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University of Melbourne
1.
Ng, Amanda Ching Lih.
Techniques for the processing and analysis of magnetic resonance imaging phase data.
Degree: 2013, University of Melbourne
URL: http://hdl.handle.net/11343/38674
► From its beginnings in the 1970s, the medical imaging field of magnetic resonance (MR) imaging has focussed primarily on the magnitude of the acquired complex…
(more)
▼ From its beginnings in the 1970s, the medical imaging field of magnetic resonance (MR) imaging has focussed primarily on the magnitude of the acquired complex data. With ever increasing magnet field strengths, interest in the phase, or argument, of complex T2*-weighted gradient echo MR data has grown. Compared to magnitude images, phase images provide novel contrast and increased sensitivity to tissue properties such as magnetic susceptibility.
Several post-acquisition processing methods exploit this sensitivity to susceptibility, notably Susceptibility-Weighted Imaging (SWI) and Quantitative Susceptibility Mapping (QSM). These methods provide greater contrast valuable in the visualisation of biological structures, such as venous vessels, tumours, haemorrhages and subcortical structures. QSM, in particular, may provide the ability to infer changes in chemical composition, such as iron deposition, which is important in the progression of several neurodegenerative disorders such as Parkinson's Disease and Alzheimer's Disease.
Phase imaging-based methods such as SWI and QSM operate on processed phase data. The argument of a complex number is inherently circular, and the MR phase is often affected by spatially slow varying inhomogeneities. In order to extract the localised phase contrast required for SWI and QSM, a combination of phase unwrapping and high pass filtering is necessary. This task is non-trivial, with several methods having been proposed in the literature.
This thesis investigates the processing and analysis of MR phase imaging, proposing four novel techniques that address boundary artefacts introduced by existing phase processing methods, correct for inaccurate structural segmentation in standard SWI at high field strengths, provide optimised contrast images through the combination of magnitude and phase data, and increase accuracy in magnetic susceptibility estimation in QSM.
Subjects/Keywords: MRI; phase imaging; biomedical imaging
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APA (6th Edition):
Ng, A. C. L. (2013). Techniques for the processing and analysis of magnetic resonance imaging phase data. (Doctoral Dissertation). University of Melbourne. Retrieved from http://hdl.handle.net/11343/38674
Chicago Manual of Style (16th Edition):
Ng, Amanda Ching Lih. “Techniques for the processing and analysis of magnetic resonance imaging phase data.” 2013. Doctoral Dissertation, University of Melbourne. Accessed January 19, 2021.
http://hdl.handle.net/11343/38674.
MLA Handbook (7th Edition):
Ng, Amanda Ching Lih. “Techniques for the processing and analysis of magnetic resonance imaging phase data.” 2013. Web. 19 Jan 2021.
Vancouver:
Ng ACL. Techniques for the processing and analysis of magnetic resonance imaging phase data. [Internet] [Doctoral dissertation]. University of Melbourne; 2013. [cited 2021 Jan 19].
Available from: http://hdl.handle.net/11343/38674.
Council of Science Editors:
Ng ACL. Techniques for the processing and analysis of magnetic resonance imaging phase data. [Doctoral Dissertation]. University of Melbourne; 2013. Available from: http://hdl.handle.net/11343/38674

Washington University in St. Louis
2.
Hai, Pengfei.
Photoacoustic Elastography and Next-generation Photoacoustic Tomography Techniques Towards Clinical Translation.
Degree: PhD, Biomedical Engineering, 2018, Washington University in St. Louis
URL: https://openscholarship.wustl.edu/eng_etds/325
► Ultrasonically probing optical absorption, photoacoustic tomography (PAT) combines rich optical contrast with high ultrasonic resolution at depths beyond the optical diffusion limit. With consistent…
(more)
▼ Ultrasonically probing optical absorption, photoacoustic tomography (PAT) combines rich optical contrast with high ultrasonic resolution at depths beyond the optical diffusion limit. With consistent optical absorption contrast at different scales and highly scalable spatial resolution and penetration depth, PAT holds great promise as an important tool for both fundamental research and clinical application. Despite tremendous progress, PAT still encounters certain limitations that prevent it from becoming readily adopted in the clinical settings. This dissertation aims to advance both the technical development and application of PAT towards its clinical translation. The first part of this dissertation describes the development of photoacoustic elastography techniques, which complement PAT with the capability to image the elastic properties of biological tissue and detect pathological conditions associated with its alterations. First, I demonstrated vascular-elastic PAT (VE-PAT), capable of quantifying blood vessel compliance changes due to thrombosis and occlusions. Then, I developed photoacoustic elastography to noninvasively map the elasticity distribution in biological tissue. Third, I further enhanced its performance by combing conventional photoacoustic elastography with a stress sensor having known stress–strain behavior to achieve quantitative photoacoustic elastography (QPAE). QPAE can quantify the Young’s modulus of biological tissues on an absolute scale. The second part of this dissertation introduces technical improvements of photoacoustic microscopy (PAM). First, by employing near-infrared (NIR) light for illumination, a greater
imaging depth and finer lateral resolution were achieved by near-infrared optical-resolution PAM (NIR-OR-PAM). In addition, NIR-OR-PAM was capable of
imaging other tissue components, including lipid and melanin. Second, I upgraded a high-speed functional OR-PAM (HF-OR-PAM) system and applied it to image neurovascular coupling during epileptic seizure propagation in mouse brains in vivo with high spatio-temporal resolution. Last, I developed a single-cell metabolic PAM (SCM-PAM) system, which improves the current single-cell oxygen consumption rate (OCR) measurement throughput from ~30 cells over 15 minutes to ~3000 cells over 15 minutes. This throughput enhancement of two orders of magnitude achieves modeling of single-cell OCR distribution with a statistically meaningful cell count. SCM-PAM enables
imaging of intratumoral metabolic heterogeneity with single-cell resolution. The third part of this dissertation introduces the application of linear-array-based PAT (LA-PAT) in label-free high-throughput
imaging of melanoma circulating tumor cells (CTCs) in patients in vivo. Taking advantage of the strong optical absorption of melanin and the unique capability of PAT to image optical absorption, with 100% relative sensitivity, at depths with high ultrasonic spatial resolution, LA-PAT is inherently suitable for melanoma CTC
imaging. First, with a center ultrasonic…
Advisors/Committee Members: Lihong V. Wang, Mark Anastasio, Philip V. Bayly, Jin-Moo Lee, James G. Miller.
Subjects/Keywords: Biomedical imaging; Elastography; Optical imaging; Photoacoustic imaging; Biomedical Engineering and Bioengineering
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
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to Zotero / EndNote / Reference
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APA (6th Edition):
Hai, P. (2018). Photoacoustic Elastography and Next-generation Photoacoustic Tomography Techniques Towards Clinical Translation. (Doctoral Dissertation). Washington University in St. Louis. Retrieved from https://openscholarship.wustl.edu/eng_etds/325
Chicago Manual of Style (16th Edition):
Hai, Pengfei. “Photoacoustic Elastography and Next-generation Photoacoustic Tomography Techniques Towards Clinical Translation.” 2018. Doctoral Dissertation, Washington University in St. Louis. Accessed January 19, 2021.
https://openscholarship.wustl.edu/eng_etds/325.
MLA Handbook (7th Edition):
Hai, Pengfei. “Photoacoustic Elastography and Next-generation Photoacoustic Tomography Techniques Towards Clinical Translation.” 2018. Web. 19 Jan 2021.
Vancouver:
Hai P. Photoacoustic Elastography and Next-generation Photoacoustic Tomography Techniques Towards Clinical Translation. [Internet] [Doctoral dissertation]. Washington University in St. Louis; 2018. [cited 2021 Jan 19].
Available from: https://openscholarship.wustl.edu/eng_etds/325.
Council of Science Editors:
Hai P. Photoacoustic Elastography and Next-generation Photoacoustic Tomography Techniques Towards Clinical Translation. [Doctoral Dissertation]. Washington University in St. Louis; 2018. Available from: https://openscholarship.wustl.edu/eng_etds/325

The Ohio State University
3.
Huang, Jiwei.
Multispectral Imaging of Skin Oxygenation.
Degree: PhD, Biophysics, 2012, The Ohio State University
URL: http://rave.ohiolink.edu/etdc/view?acc_num=osu1356637098
► This research focuses on the investigation of a multispectral imaging technique for quantitative measurement of skin tissue oxygen saturation (StO2). Oxygen saturation is the percentage…
(more)
▼ This research focuses on the investigation of a
multispectral
imaging technique for quantitative measurement of
skin tissue oxygen saturation (StO2). Oxygen saturation is the
percentage of oxygen carried in the blood over the total oxygen
carrying capacity of blood. Skin StO2 is an important indicator of
skin tissue clinical status. Measurement of skin tissue oxygenation
has been in many clinical applications such as cosmetic product
development, chronic wound care and plastic surgery tissue recovery
monitoring. For decades, researchers have been investigating
optical spectroscopy and
imaging techniques for measuring tissue
oxygen saturation. However, many existing techniques are subjective
and qualitative due to background bias, tissue heterogeneity, and
inter-patient variation. A technique for quantitative and reliable
measurement of skin tissue oxygen saturation is necessary.
Multispectral / hyperspectral
imaging is a promising technique
which has been proposed for quantitative measurement of skin StO2
by capturing and analyzing skin images at multiple wavelengths.This
dissertation reports a multispectral
imaging method which is
capable of (1) quantitative measurement of skin oxygen saturation
with minimal bias from different skin types, and (2)
imaging skin
oxygen saturation dynamics. There’re mainly three parts of this
research.First, theoretical study and algorithm development. A
numerical model was established to simulate skin tissue reflectance
of different skin conditions including oxygen saturation, blood
concentration, tissue scattering and melanin concentration. From
the simulation result, a parameter SDR, which can be calculated
from skin reflectance images of 544, 552, 568, 576, 592, 600nm, was
found to be mainly determined by oxygenation regardless of
different tissue conditions. Thus, skin oxygen saturation can be
measured by taking multispectral images of six wavelengths. Second,
imaging system development. A multispectral / hyperspectral
imaging
system was built by integrating camera, filter and light source. A
graphical user interface was developed for equipment control,
synchronization and image acquisition.
Imaging processing algorithm
was developed for generation of skin oxygen saturation map from the
reflectance image of six wavelengths. Third, benchtop experiments
and human
subject test. The
imaging method was first verified using
a phantom which was a liquid mixture of different concentrations of
blood, intralipid and ink to simulate different skin conditions.
StO2 measured by our method was not affected by the different
concentration of phantom materials. Then, multispectral
imaging of
skin oxygenation was demonstrated by a human
subject test in which
10 subjects with different skin types were recruited. The variation
of skin StO2(%) measured by multispectral
imaging is over two times
smaller than the measurements from other two oximetry techniques,
which indicates that skin StO2 measurement by our method is not
affected by different skin types. After that, skin StO2 dynamics
was measured…
Advisors/Committee Members: Xu, Ronald (Committee Chair).
Subjects/Keywords: Biomedical Engineering; Biomedical Research; Medical Imaging; Optics
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Huang, J. (2012). Multispectral Imaging of Skin Oxygenation. (Doctoral Dissertation). The Ohio State University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=osu1356637098
Chicago Manual of Style (16th Edition):
Huang, Jiwei. “Multispectral Imaging of Skin Oxygenation.” 2012. Doctoral Dissertation, The Ohio State University. Accessed January 19, 2021.
http://rave.ohiolink.edu/etdc/view?acc_num=osu1356637098.
MLA Handbook (7th Edition):
Huang, Jiwei. “Multispectral Imaging of Skin Oxygenation.” 2012. Web. 19 Jan 2021.
Vancouver:
Huang J. Multispectral Imaging of Skin Oxygenation. [Internet] [Doctoral dissertation]. The Ohio State University; 2012. [cited 2021 Jan 19].
Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1356637098.
Council of Science Editors:
Huang J. Multispectral Imaging of Skin Oxygenation. [Doctoral Dissertation]. The Ohio State University; 2012. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1356637098
4.
Lakhotia, Kritika.
Visualization and quantification of 3D tumor-host interface architecture reconstructed from digital histopathology slides.
Degree: 2016, State University of New York at Buffalo
URL: http://pqdtopen.proquest.com/#viewpdf?dispub=10127616
► Oral cavity cancer (OCC) is a type of cancer of the lip, tongue, salivary glands and other sites in the mouth <i>(buccal or oral…
(more)
▼ Oral cavity cancer (OCC) is a type of cancer of the lip, tongue, salivary glands and other sites in the mouth <i>(buccal or oral cavity)</i> and is the sixth leading cause of cancer worldwide. Patients with OCC are treated based on a staging system: low-stage patients typically receive less aggressive therapy compared to high-stage patients. Unfortunately, low-stage patients are sometimes at risk for locoregional recurrence. Recently, a semi-quantitative risk scoring system has been developed to assess the locoregional recurrence risk for low-stage patients. This risk scoring system is based on tissue characteristics determined on 2D histopathology images under a microscope. This modality limits the appreciation of the 3D architecture of the tumor and its associated morphological features. This thesis aims to visualize 3D models of the tumor-host interface reconstructed from serially-sectioned histopathology slides and quantify their clinically validated morphological features to predict locoregional recurrence after treatment. The 3D models are developed and quantified for 6 patient cases using readily available tools. This pilot study provides a framework for an automated diagnostic technique for 3D visualization and morphological analysis of tumor biology which is traditionally done using 2D analysis.
Subjects/Keywords: Biomedical engineering; Medical imaging
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Lakhotia, K. (2016). Visualization and quantification of 3D tumor-host interface architecture reconstructed from digital histopathology slides. (Thesis). State University of New York at Buffalo. Retrieved from http://pqdtopen.proquest.com/#viewpdf?dispub=10127616
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Lakhotia, Kritika. “Visualization and quantification of 3D tumor-host interface architecture reconstructed from digital histopathology slides.” 2016. Thesis, State University of New York at Buffalo. Accessed January 19, 2021.
http://pqdtopen.proquest.com/#viewpdf?dispub=10127616.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lakhotia, Kritika. “Visualization and quantification of 3D tumor-host interface architecture reconstructed from digital histopathology slides.” 2016. Web. 19 Jan 2021.
Vancouver:
Lakhotia K. Visualization and quantification of 3D tumor-host interface architecture reconstructed from digital histopathology slides. [Internet] [Thesis]. State University of New York at Buffalo; 2016. [cited 2021 Jan 19].
Available from: http://pqdtopen.proquest.com/#viewpdf?dispub=10127616.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lakhotia K. Visualization and quantification of 3D tumor-host interface architecture reconstructed from digital histopathology slides. [Thesis]. State University of New York at Buffalo; 2016. Available from: http://pqdtopen.proquest.com/#viewpdf?dispub=10127616
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
5.
Vaidya, Manushka.
Steering Electromagnetic Fields in MRI| Investigating Radiofrequency Field Interactions with Endogenous and External Dielectric Materials for Improved Coil Performance at High Field.
Degree: 2017, New York University
URL: http://pqdtopen.proquest.com/#viewpdf?dispub=10261392
► Although 1.5 and 3 Tesla (T) magnetic resonance (MR) systems remain the clinical standard, the number of 7 T MR systems has increased over…
(more)
▼ Although 1.5 and 3 Tesla (T) magnetic resonance (MR) systems remain the clinical standard, the number of 7 T MR systems has increased over the past decade because of the promise of higher signal-to-noise ratio (SNR), which can translate to images with higher resolution, improved image quality and faster acquisition times. However, there are a number of technical challenges that have prevented exploiting the full potential of ultra-high field (≥ 7 T) MR imaging (MRI), such as the inhomogeneous distribution of the radiofrequency (RF) electromagnetic field and specific energy absorption rate (SAR), which can compromise image quality and patient safety. To better understand the origin of these issues, we first investigated the dependence of the spatial distribution of the magnetic field associated with a surface RF coil on the operating frequency and electrical properties of the sample. Our results demonstrated that the asymmetries between the transmit (<i>B</i>1+) and receive (<i>B</i> 1<sup>–</sup>) circularly polarized components of the magnetic field, which are in part responsible for RF inhomogeneity, depend on the electric conductivity of the sample. On the other hand, when sample conductivity is low, a high relative permittivity can result in an inhomogeneous RF field distribution, due to significant constructive and destructive interference patterns between forward and reflected propagating magnetic field within the sample. We then investigated the use of high permittivity materials (HPMs) as a method to alter the field distribution and improve transmit and receive coil performance in MRI. We showed that HPM placed at a distance from an RF loop coil can passively shape the field within the sample. Our results showed improvement in transmit and receive sensitivity overlap, extension of coil field-of-view, and enhancement in transmit/receive efficiency. We demonstrated the utility of this concept by employing HPM to improve performance of an existing commercial head coil for the inferior regions of the brain, where the specific coil’s imaging efficiency was inherently poor. Results showed a gain in SNR, while the maximum local and head SAR values remained below the prescribed limits. We showed that increasing coil performance with HPM could improve detection of functional MR activation during a motor-based task for whole brain fMRI. Finally, to gain an intuitive understanding of how HPM improves coil performance, we investigated how HPM separately affects signal and noise sensitivity to improve SNR. For this purpose, we employed a theoretical model based on dyadic Green’s functions to compare the characteristics of current patterns, i.e. the optimal spatial distribution of coil conductors, that would either maximize SNR (ideal current patterns), maximize signal reception (signal-only optimal current patterns), or minimize sample noise (dark mode current patterns). Our results demonstrated that the presence of a lossless HPM…
Subjects/Keywords: Biomedical engineering; Medical imaging; Physics
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Vaidya, M. (2017). Steering Electromagnetic Fields in MRI| Investigating Radiofrequency Field Interactions with Endogenous and External Dielectric Materials for Improved Coil Performance at High Field. (Thesis). New York University. Retrieved from http://pqdtopen.proquest.com/#viewpdf?dispub=10261392
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Vaidya, Manushka. “Steering Electromagnetic Fields in MRI| Investigating Radiofrequency Field Interactions with Endogenous and External Dielectric Materials for Improved Coil Performance at High Field.” 2017. Thesis, New York University. Accessed January 19, 2021.
http://pqdtopen.proquest.com/#viewpdf?dispub=10261392.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Vaidya, Manushka. “Steering Electromagnetic Fields in MRI| Investigating Radiofrequency Field Interactions with Endogenous and External Dielectric Materials for Improved Coil Performance at High Field.” 2017. Web. 19 Jan 2021.
Vancouver:
Vaidya M. Steering Electromagnetic Fields in MRI| Investigating Radiofrequency Field Interactions with Endogenous and External Dielectric Materials for Improved Coil Performance at High Field. [Internet] [Thesis]. New York University; 2017. [cited 2021 Jan 19].
Available from: http://pqdtopen.proquest.com/#viewpdf?dispub=10261392.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Vaidya M. Steering Electromagnetic Fields in MRI| Investigating Radiofrequency Field Interactions with Endogenous and External Dielectric Materials for Improved Coil Performance at High Field. [Thesis]. New York University; 2017. Available from: http://pqdtopen.proquest.com/#viewpdf?dispub=10261392
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of California – Irvine
6.
Le, Vivian.
Self-Assembly of an Optically-Responsive Polydiacetylene-Coating on Iron Ferrite Magnetic Nanoparticles for Tumor Detection and Targeting.
Degree: Chemical and Biochemical Engineering, 2016, University of California – Irvine
URL: http://www.escholarship.org/uc/item/066162xs
► Nanoparticles are a promising diagnostic agent with applications in tumor imaging and targeted cancer treatment. They can offer multifunctional properties by combining imaging methods to…
(more)
▼ Nanoparticles are a promising diagnostic agent with applications in tumor imaging and targeted cancer treatment. They can offer multifunctional properties by combining imaging methods to improve cancer diagnosis, treatment, and disease monitoring. Two such complementary tools are magnetic resonance imaging (MRI) and fluorescence imaging. In this thesis, a dual solvent exchange approach was chosen to facilitate the self-assembly of amphiphlic diacetylene monomers onto hydrophobic iron ferrite magnetic nanoparticles (MNPs). Various concentrations of the diacetylene monomers, 10,12-pentacosadiynoic acid (PCDA) and 10,12-heptacosadiynoic acid (HCDA), were coated onto ~14 nm iron ferrite MNPs. The diacetylene monomer coating were cross-linked to a stable blue colored polydiacetylene (PDA) coating after applying UV light. The resulting PDA-MNP hybrid displayed characteristic chromogenic and fluorogenic in response to thermal stress. This novel multifunctional nanoparticle system holds exciting potential for dual-modality diagnostics applications.
Subjects/Keywords: Nanotechnology; Biomedical engineering; Medical imaging
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Le, V. (2016). Self-Assembly of an Optically-Responsive Polydiacetylene-Coating on Iron Ferrite Magnetic Nanoparticles for Tumor Detection and Targeting. (Thesis). University of California – Irvine. Retrieved from http://www.escholarship.org/uc/item/066162xs
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Le, Vivian. “Self-Assembly of an Optically-Responsive Polydiacetylene-Coating on Iron Ferrite Magnetic Nanoparticles for Tumor Detection and Targeting.” 2016. Thesis, University of California – Irvine. Accessed January 19, 2021.
http://www.escholarship.org/uc/item/066162xs.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Le, Vivian. “Self-Assembly of an Optically-Responsive Polydiacetylene-Coating on Iron Ferrite Magnetic Nanoparticles for Tumor Detection and Targeting.” 2016. Web. 19 Jan 2021.
Vancouver:
Le V. Self-Assembly of an Optically-Responsive Polydiacetylene-Coating on Iron Ferrite Magnetic Nanoparticles for Tumor Detection and Targeting. [Internet] [Thesis]. University of California – Irvine; 2016. [cited 2021 Jan 19].
Available from: http://www.escholarship.org/uc/item/066162xs.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Le V. Self-Assembly of an Optically-Responsive Polydiacetylene-Coating on Iron Ferrite Magnetic Nanoparticles for Tumor Detection and Targeting. [Thesis]. University of California – Irvine; 2016. Available from: http://www.escholarship.org/uc/item/066162xs
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of California – Berkeley
7.
Croft, Laura Rose.
Relaxation in Magnetic Particle Imaging.
Degree: Bioengineering, 2013, University of California – Berkeley
URL: http://www.escholarship.org/uc/item/4tm8n7kh
► Magnetic particle imaging (MPI) is a novel medical imaging modality that spatially detects a tracer of superparamagnetic iron oxide nanoparticles (SPIOs) with high sensitivity, contrast,…
(more)
▼ Magnetic particle imaging (MPI) is a novel medical imaging modality that spatially detects a tracer of superparamagnetic iron oxide nanoparticles (SPIOs) with high sensitivity, contrast, and no tissue penetration limitations. MPI has great potential for safer angiography, in vivo cell tracking, and cancer detection, among other applications. Current MPI theoretical descriptions and reconstruction techniques make an adiabatic assumption that the SPIO tracer instantaneously follows the applied magnetic fields of the MPI scanner. This assumption is not strictly true, and we refer to SPIO magnetization delays as relaxation effects.We begin by extending the x-space theory of MPI to include relaxation effects. We choose this MPI theory because it directly converts the temporal MPI signal to the image (spatial) domain, lending itself well to investigating how relaxation time delays translate into spatial effects. Using the non-adiabatic x-space theory and experimentally-measured data, we demonstrate that relaxation blurs the x-space image in the scanning direction. Next, we study how we may design MPI scanning sequences to minimize relaxation-induced blurring. From the non-adiabatic x-space theory we derive a mathematical description of how this blur can vary with scanning parameters for a given relaxation time. We compare theoretical predictions to experimental data by measuring relaxation times and spatial resolution under various scanning conditions. Despite increased relaxation time delays with slower scanning conditions, we observe that relaxation-induced blurring can be minimized when scanning slower. Finally, we derive a magnetic field-driven relaxation mechanism called magneto-viscous relaxation. This mechanism describes how the applied magnetic field creates a magnetic torque on the SPIO, inducing physical rotation of the SPIO to align with the field; however viscous resistance of the carrier liquid hinders this movement. We compare predicted relaxation times to measured values for a range of SPIO characteristics and scanning conditions. In this dissertation, we show how relaxation can have deleterious effects on the MPI signal and image. We explore how relaxation-induced blurring and relaxation times may be minimized through improved SPIO characteristics and MPI scanning sequence design. In addition to improving MPI image quality, this important area of research can lead to future clinical applications. Using this knowledge and specially-designed MPI pulse sequences, we can exploit variations in relaxation behavior as a source of contrast, which will increase the diagnostic potential of MPI.
Subjects/Keywords: Biomedical engineering; Medical imaging
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Croft, L. R. (2013). Relaxation in Magnetic Particle Imaging. (Thesis). University of California – Berkeley. Retrieved from http://www.escholarship.org/uc/item/4tm8n7kh
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Croft, Laura Rose. “Relaxation in Magnetic Particle Imaging.” 2013. Thesis, University of California – Berkeley. Accessed January 19, 2021.
http://www.escholarship.org/uc/item/4tm8n7kh.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Croft, Laura Rose. “Relaxation in Magnetic Particle Imaging.” 2013. Web. 19 Jan 2021.
Vancouver:
Croft LR. Relaxation in Magnetic Particle Imaging. [Internet] [Thesis]. University of California – Berkeley; 2013. [cited 2021 Jan 19].
Available from: http://www.escholarship.org/uc/item/4tm8n7kh.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Croft LR. Relaxation in Magnetic Particle Imaging. [Thesis]. University of California – Berkeley; 2013. Available from: http://www.escholarship.org/uc/item/4tm8n7kh
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Cornell University
8.
Horton, Nicholas.
Three-Photon Microscopy At 1700 Nm For In Vivo Imaging.
Degree: PhD, Applied Physics, 2015, Cornell University
URL: http://hdl.handle.net/1813/40694
► Multiphoton fluorescence microscopy (MPM) allows scientists to noninvasively observe structures deep within tissue. Two-photon microscopy (2PM) in the 750-1000 nm excitation region has been the…
(more)
▼ Multiphoton fluorescence microscopy (MPM) allows scientists to noninvasively observe structures deep within tissue. Two-photon microscopy (2PM) in the 750-1000 nm excitation region has been the standard MPM technique since its first demonstration in 1990. However, the maximum
imaging depth for 2PM is limited by the signal-to-background ratio (SBR). In this dissertation, three-photon
imaging at 1700 nm excitation wavelength (1700 nm 3PM) is presented. The combination of the long excitation wavelength and the higher order nonlinear excitation overcomes the SBR limitations of 2PM, enabling biological investigations to take place at greater depth within tissue. In chapter 1, tissue
imaging is discussed, paying special attention to the development of laser scanning fluorescence microscopy. In chapter 2, non-invasive, high resolution, in vivo
imaging of subcortical structures within an intact mouse brain using 1700 nm 3PM is presented. Vascular structures as well as red fluorescent protein (RFP)-labeled neurons within the mouse hippocampus are imaged. In chapter 3, dispersion compensation of 1700 nm 3PM is discussed. Signal generation in 3PM is proportional to the inverse-squared of the pulse width. We show that the high normal dispersion of a silicon wafer can be conveniently used to compensate the anomalous dispersion of a 1,700 nm excitation three-photon microscope. We achieved over a factor of two reduction in pulse width at the sample, which corresponded to over a 4x increase in the three-photon signal. This signal increase was demonstrated within the mouse brain in vivo. In chapter 4, through-skull
imaging using 1700 nm 3PM is demonstrated. The strong scattering properties of the skull traditionally require either its partial or total removal in order to achieve a sufficient penetration depth. Skull modifications have been shown to alter brain properties, which can subsequently affect
imaging experiments. We demonstrate in vivo vascular
imaging 720 m below the skull-brain interface through an unthinned, intact mouse skull and RFP-labeled neuron
imaging 350 m below the skull-brain interface. Our results show that long-wavelength 3PM has the potential to perform high spatial resolution in vivo
imaging deep in the mouse brain without the removal of the skull.
Advisors/Committee Members: Xu,Chunhui (chair), Schaffer,Chris (committee member), Harris-Warrick,Ronald Morgan (committee member).
Subjects/Keywords: Multiphoton Microscopy; Biomedical Imaging; Optics
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APA (6th Edition):
Horton, N. (2015). Three-Photon Microscopy At 1700 Nm For In Vivo Imaging. (Doctoral Dissertation). Cornell University. Retrieved from http://hdl.handle.net/1813/40694
Chicago Manual of Style (16th Edition):
Horton, Nicholas. “Three-Photon Microscopy At 1700 Nm For In Vivo Imaging.” 2015. Doctoral Dissertation, Cornell University. Accessed January 19, 2021.
http://hdl.handle.net/1813/40694.
MLA Handbook (7th Edition):
Horton, Nicholas. “Three-Photon Microscopy At 1700 Nm For In Vivo Imaging.” 2015. Web. 19 Jan 2021.
Vancouver:
Horton N. Three-Photon Microscopy At 1700 Nm For In Vivo Imaging. [Internet] [Doctoral dissertation]. Cornell University; 2015. [cited 2021 Jan 19].
Available from: http://hdl.handle.net/1813/40694.
Council of Science Editors:
Horton N. Three-Photon Microscopy At 1700 Nm For In Vivo Imaging. [Doctoral Dissertation]. Cornell University; 2015. Available from: http://hdl.handle.net/1813/40694

Purdue University
9.
Shen, Litao.
Diffusion tensor imaging application.
Degree: 2015, Purdue University
URL: http://pqdtopen.proquest.com/#viewpdf?dispub=1602902
► Central nervous system (CNS) related conditions and diseases like mild traumatic brain injury (mTBI) and multiple sclerosis (MS) affect people’s life quality, yet there…
(more)
▼ Central nervous system (CNS) related conditions and diseases like mild traumatic brain injury (mTBI) and multiple sclerosis (MS) affect people’s life quality, yet there is no single test for the diagnosis of these diseases or conditions. Patients may need to wait for years until they are diagnosed correctly to get the correct treatment, which is often too late. Thus, there is a strong need to develop some techniques to aid the diagnosis of CNS-related conditions and diseases. The conventional MRI can reveal the structure of the brain but cannot detect the difference between the healthy tissue and the anomalies. Diffusion tensor imaging (DTI) has been used for detecting white matter integrity and demyelination for the past decade in experiments and has been proven to have the ability to depict the problem effectively. In the past decade, many techniques were found based on DTI data, and these techniques improved pre-processing, processing, and post-processing. Though there are many software and APIs that can provide functions for DTI file input/output (IO), visualization and other DTI related topics, there is no general software or API that is dedicated to covering the whole processing procedure of DTI that at the same time can be extended easily by the user. This thesis is dedicated to developing a software that can be used to aid in the diagnosis of CNS-related conditions and diseases while at the same time trying to cover as many topics as possible. Another purpose is to make the software highly extensible. This thesis work first introduces the background of CNS-related disease and uses MS as an example to introduce the process of demyelination and the white matter integrity problem, which are involved in these CNS-related diseases and conditions. Then the diffusion process and the technique that can detect the diffusion signal (DTI) is presented. After this, concepts and meaning of the secondary metrics are discussed. Then, current existing software and APIs and their advantages and disadvantages are outlined. After these points, the techniques that are discussed in this thesis as well as their advantages are outlined. This part is followed by the charts and code samples which can illustrate the process and structure of this software. Then different modules and their results are explained. In this software, the results are represented by images and 3D models. There are color images, pseudo color images with different schemes and gray scale images. Images are mainly included to represent the FA and MD data. In this software, streamlines are generated from the eigenvalue and eigenvector. Then a bundled result for the streamline is also realized in this software. The streamline and bundled results are 3D models. For 3D models, there are mainly two ways to display the real 3D model. One is the naked eye 3D which doesn’t require the user to wear glasses but has less stereoscopic characteristics. As the stereoscopic monitors and glasses are more and more popular and…
Subjects/Keywords: Biomedical engineering; Medical imaging
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Chicago ·
MLA ·
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APA (6th Edition):
Shen, L. (2015). Diffusion tensor imaging application. (Thesis). Purdue University. Retrieved from http://pqdtopen.proquest.com/#viewpdf?dispub=1602902
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Shen, Litao. “Diffusion tensor imaging application.” 2015. Thesis, Purdue University. Accessed January 19, 2021.
http://pqdtopen.proquest.com/#viewpdf?dispub=1602902.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Shen, Litao. “Diffusion tensor imaging application.” 2015. Web. 19 Jan 2021.
Vancouver:
Shen L. Diffusion tensor imaging application. [Internet] [Thesis]. Purdue University; 2015. [cited 2021 Jan 19].
Available from: http://pqdtopen.proquest.com/#viewpdf?dispub=1602902.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Shen L. Diffusion tensor imaging application. [Thesis]. Purdue University; 2015. Available from: http://pqdtopen.proquest.com/#viewpdf?dispub=1602902
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
10.
Gordon, Andrew Christian.
Tuning Your RADIOembolization| Imaging-guidance of Yttrium-90 Radioembolization.
Degree: 2016, Northwestern University
URL: http://pqdtopen.proquest.com/#viewpdf?dispub=10160495
► Hepatocellular carcinoma (HCC) is the second leading cause of cancer death in the world and the liver is a common site of metastases from…
(more)
▼ Hepatocellular carcinoma (HCC) is the second leading cause of cancer death in the world and the liver is a common site of metastases from other primary neoplasms. Many patients are not surgical candidates. Radioembolization is an intra-arterial therapy delivering high doses of radiation emitted from microspheres infused selectively into the tumor feeding arteries. These microspheres land in the tumor microcirculation and deposit radiation to the tumor tissues. Over the past ten years, radioembolization has become part of the treatment guidelines for unresectable HCC, liver-dominant metastatic colorectal cancer, and neuroendocrine liver metastases, and it is often used in the salvage setting for patients with hepatic malignancy progressing on other therapies. The overarching goal of the thesis work was to advance the basic science of 90Y radioembolization based on existing clinical needs to ultimately improve patient outcomes. This included 1) setup of pre-clinical laboratory to study radioembolization, 2) optimization of radioembolization protocols in research animals, 3) validation of 90Y PET/CT imaging techniques to monitor microsphere delivery and dosing, 4) blood oxygen-level dependent (BOLD) imaging and evaluation of tumor biology and physiology after radioembolization in the VX2 rabbit model at a fixed dose of 50 Gy, 5) evaluation of normal tissue pathology (fibrosis, atrophy) and biology (hepatocyte proliferation, microvessel density, stellate cell activation) in rats after 90Y radiation lobectomy at clinically relevant dosing from 150 to >4,000 Gy, and 6) development of new yttrium microsphere compositions for combination therapy with electromagnetic hyperthermia.
Subjects/Keywords: Biomedical engineering; Medical imaging; Oncology
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Chicago ·
MLA ·
Vancouver ·
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Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Gordon, A. C. (2016). Tuning Your RADIOembolization| Imaging-guidance of Yttrium-90 Radioembolization. (Thesis). Northwestern University. Retrieved from http://pqdtopen.proquest.com/#viewpdf?dispub=10160495
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Gordon, Andrew Christian. “Tuning Your RADIOembolization| Imaging-guidance of Yttrium-90 Radioembolization.” 2016. Thesis, Northwestern University. Accessed January 19, 2021.
http://pqdtopen.proquest.com/#viewpdf?dispub=10160495.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Gordon, Andrew Christian. “Tuning Your RADIOembolization| Imaging-guidance of Yttrium-90 Radioembolization.” 2016. Web. 19 Jan 2021.
Vancouver:
Gordon AC. Tuning Your RADIOembolization| Imaging-guidance of Yttrium-90 Radioembolization. [Internet] [Thesis]. Northwestern University; 2016. [cited 2021 Jan 19].
Available from: http://pqdtopen.proquest.com/#viewpdf?dispub=10160495.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Gordon AC. Tuning Your RADIOembolization| Imaging-guidance of Yttrium-90 Radioembolization. [Thesis]. Northwestern University; 2016. Available from: http://pqdtopen.proquest.com/#viewpdf?dispub=10160495
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Toronto
11.
Atchia, Yaaseen.
Optical Neural Imaging in Rodents using VCSELs.
Degree: 2013, University of Toronto
URL: http://hdl.handle.net/1807/42673
► Optical brain imaging is proven to be useful to understand brain function and morphology at cellular and network level. Different optical imaging modalities were developed…
(more)
▼ Optical brain imaging is proven to be useful to understand brain function and morphology at cellular and network level. Different optical imaging modalities were developed over the years, with our group developing multi-modal simultaneous imaging using Vertical Cavity Surface Emitting Lasers (VCSELs). This thesis improves and demonstrates the applicability of the imaging system and adapts it to portable imaging. Specifically, it was found that using multiple exposures provide better flow measurements when compared to tracking measurements. An intrinsic parameter to monitor the state of the Blood Brain Barrier (BBB) was also discovered, proving more practical than previous fluorescence methods. We finally demonstrate initial results of imaging flow velocities and fluorescence in awake and moving rodents using VCSELs, achromatic doublets and a CMOS camera. Future work involves developing new prototypes of the portable system for imaging of disease states in awake animals and minimizing movement artefacts for oxygenation measurements.
MAST
Advisors/Committee Members: Levi, Ofer, Electrical and Computer Engineering.
Subjects/Keywords: Biomedical Imaging; VCSEL; 0544; 0541
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Atchia, Y. (2013). Optical Neural Imaging in Rodents using VCSELs. (Masters Thesis). University of Toronto. Retrieved from http://hdl.handle.net/1807/42673
Chicago Manual of Style (16th Edition):
Atchia, Yaaseen. “Optical Neural Imaging in Rodents using VCSELs.” 2013. Masters Thesis, University of Toronto. Accessed January 19, 2021.
http://hdl.handle.net/1807/42673.
MLA Handbook (7th Edition):
Atchia, Yaaseen. “Optical Neural Imaging in Rodents using VCSELs.” 2013. Web. 19 Jan 2021.
Vancouver:
Atchia Y. Optical Neural Imaging in Rodents using VCSELs. [Internet] [Masters thesis]. University of Toronto; 2013. [cited 2021 Jan 19].
Available from: http://hdl.handle.net/1807/42673.
Council of Science Editors:
Atchia Y. Optical Neural Imaging in Rodents using VCSELs. [Masters Thesis]. University of Toronto; 2013. Available from: http://hdl.handle.net/1807/42673

University of Washington
12.
Hammond, Ryan.
Reduction of Off-Axis Clutter in Plane-wave Ultrasound Imaging.
Degree: 2020, University of Washington
URL: http://hdl.handle.net/1773/45841
► In ultrasound imaging, an abrupt change in medium, such as the interface between tissue and bone can have a dramatic effect on the image. A…
(more)
▼ In ultrasound
imaging, an abrupt change in medium, such as the interface between tissue and bone can have a dramatic effect on the image. A bone-tissue interface strongly reflects acoustic signals in comparison to soft tissue. Large amplitude scatterers can lead to artifacts spreading across adjacent regions of the tissue during the spatial filtering of beamformation. The following work investigates three different approaches to minimize the influence of large amplitude off-axis echoes, while minimally impacting regions of smaller amplitude echoes. We have observed thresholding the large amplitude signals before beamformation can prevent side lobe artifacts into lower amplitude echoes. However, the selection of thresholds too low can impact the signal of interest. Ideally, a threshold would be as high as possible to not impact signals of interest, but still adequately remove artifacts. In order to address this limitation of a simple threshold we have investigated the use of a neural net to adaptively select an optimal threshold. Lastly, we have also investigated the use of adaptive selection of aperture apodization to further suppress high amplitude off-axis signals. Specifically, we image spinal cord blood flow and changes in blood flow following spinal cord injury in a rodent model. The lamina or top of the vertebral bones are surgically removed for injury permitting ultrasound
imaging. With the spinal cord resting on top of vertebral bone, large amplitude reflections from bone can contaminate surrounding weaker reflecting spinal cord tissue. These artifacts impede visualization of blood flow and further analysis in detecting changes in blood flow resulting from spinal cord injury.
Advisors/Committee Members: Averkiou, Michalakis (advisor).
Subjects/Keywords:
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Hammond, R. (2020). Reduction of Off-Axis Clutter in Plane-wave Ultrasound Imaging. (Thesis). University of Washington. Retrieved from http://hdl.handle.net/1773/45841
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Hammond, Ryan. “Reduction of Off-Axis Clutter in Plane-wave Ultrasound Imaging.” 2020. Thesis, University of Washington. Accessed January 19, 2021.
http://hdl.handle.net/1773/45841.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Hammond, Ryan. “Reduction of Off-Axis Clutter in Plane-wave Ultrasound Imaging.” 2020. Web. 19 Jan 2021.
Vancouver:
Hammond R. Reduction of Off-Axis Clutter in Plane-wave Ultrasound Imaging. [Internet] [Thesis]. University of Washington; 2020. [cited 2021 Jan 19].
Available from: http://hdl.handle.net/1773/45841.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Hammond R. Reduction of Off-Axis Clutter in Plane-wave Ultrasound Imaging. [Thesis]. University of Washington; 2020. Available from: http://hdl.handle.net/1773/45841
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Columbia University
13.
Burgess, Sean Adam.
Development and Applications of Laminar Optical Tomography for In Vivo Imaging.
Degree: 2011, Columbia University
URL: https://doi.org/10.7916/D8XW4RRV
► Laminar optical tomography (LOT) is an optical imaging technique capable of making depth-resolved measurements of absorption and fluorescence contrast in scattering tissue. LOT was first…
(more)
▼ Laminar optical tomography (LOT) is an optical imaging technique capable of making depth-resolved measurements of absorption and fluorescence contrast in scattering tissue. LOT was first demonstrated in 2004 by Hillman et al [1]. The technique combines a non-contact laser scanning geometry, similar to a low magnification confocal microscope, with the imaging principles of diffuse optical tomography (DOT). This thesis describes the development and application of a second generation LOT system, which acquires both fluorescence and multi-wavelength measurements simultaneously and is better suited for in vivo measurements. Chapter 1 begins by reviewing the interactions of light with tissue that form the foundation of optical imaging. A range of related optical imaging techniques and the basic principles of LOT imaging are then described. In Chapter 2, the development of the new LOT imaging system is described including the implementation of a series of interfaces to allow clinical imaging. System performance is then evaluated on a range of imaging phantoms. Chapter 3 describes two in vivo imaging applications explored using the second generation LOT system, first in a clinical setting where skin lesions were imaged, and then in a laboratory setting where LOT imaging was performed on exposed rat cortex. The final chapter provides a brief summary and describes future directions for LOT. LOT has the potential to find applications in medical diagnostics, surgical guidance, and in-situ monitoring owing to its sensitivity to absorption and fluorescence contrast as well as its ability to provide depth sensitive measures. Optical techniques can characterize blood volume and oxygenation, two important biological parameters, through measurements at different wavelengths. Fluorescence measurements, either from autofluorescence or fluorescent dyes, have shown promise for identifying and analyzing lesions in various epithelial tissues including skin [2, 3], colon [4], esophagus [5, 6], oral mucosa [7, 8], and cervix [9]. The desire to capture these types of measurements with LOT motivated much of the work presented here.
Subjects/Keywords: Biomedical engineering; Diagnostic imaging
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Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Burgess, S. A. (2011). Development and Applications of Laminar Optical Tomography for In Vivo Imaging. (Doctoral Dissertation). Columbia University. Retrieved from https://doi.org/10.7916/D8XW4RRV
Chicago Manual of Style (16th Edition):
Burgess, Sean Adam. “Development and Applications of Laminar Optical Tomography for In Vivo Imaging.” 2011. Doctoral Dissertation, Columbia University. Accessed January 19, 2021.
https://doi.org/10.7916/D8XW4RRV.
MLA Handbook (7th Edition):
Burgess, Sean Adam. “Development and Applications of Laminar Optical Tomography for In Vivo Imaging.” 2011. Web. 19 Jan 2021.
Vancouver:
Burgess SA. Development and Applications of Laminar Optical Tomography for In Vivo Imaging. [Internet] [Doctoral dissertation]. Columbia University; 2011. [cited 2021 Jan 19].
Available from: https://doi.org/10.7916/D8XW4RRV.
Council of Science Editors:
Burgess SA. Development and Applications of Laminar Optical Tomography for In Vivo Imaging. [Doctoral Dissertation]. Columbia University; 2011. Available from: https://doi.org/10.7916/D8XW4RRV

Columbia University
14.
Taei-Tehrani, Mohammad Reza.
Pseudo Random Arterial Modulation (PRAM): A Novel ASL Approach to Measure Flow and Blood Transit Times.
Degree: 2012, Columbia University
URL: https://doi.org/10.7916/D88S4WWC
► The Pseudo Random Arterial Modulation (PRAM) is a non-invasive MRI based method to measure blood flow. It does not require any contrast agent but rather…
(more)
▼ The Pseudo Random Arterial Modulation (PRAM) is a non-invasive MRI based method to measure blood flow. It does not require any contrast agent but rather uses water protons in the body as the contrast. PRAM is based on a pseudo random sequence of inversions and non-inversions of the arterial blood using radio frequency (RF) pulses at a labeling plane inferior to the imaging plane. A series of images are taken at the imaging plane and flow reconstructed from the transit time measurements. PRAM does not require separate control and label acquisition as is common in Arterial Spin Labeling (ASL) but rather measures the distribution of transit times to a voxel within one integrated scan. Adiabatic inversion or non-inversion pre-pulses (PRAM pulses) are performed prior to a gradient echo imaging. The PRAM method has been tested on a flow phantom and the results were in confirmation with the theoretical flow and velocity measurements. Subsequently the PRAM method was tested on a human leg and the results were comparable with the Ultrasound measurements. The final testing phase was performed on a human brain and the results were compared with the phased contrast MRA. We have demonstrated here that that the PRAM technique can measure the velocity profile and the transit time accurately and efficiently on any organ such as human brain.
Subjects/Keywords: Biomedical engineering; Diagnostic imaging; Psychometrics
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APA ·
Chicago ·
MLA ·
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Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Taei-Tehrani, M. R. (2012). Pseudo Random Arterial Modulation (PRAM): A Novel ASL Approach to Measure Flow and Blood Transit Times. (Doctoral Dissertation). Columbia University. Retrieved from https://doi.org/10.7916/D88S4WWC
Chicago Manual of Style (16th Edition):
Taei-Tehrani, Mohammad Reza. “Pseudo Random Arterial Modulation (PRAM): A Novel ASL Approach to Measure Flow and Blood Transit Times.” 2012. Doctoral Dissertation, Columbia University. Accessed January 19, 2021.
https://doi.org/10.7916/D88S4WWC.
MLA Handbook (7th Edition):
Taei-Tehrani, Mohammad Reza. “Pseudo Random Arterial Modulation (PRAM): A Novel ASL Approach to Measure Flow and Blood Transit Times.” 2012. Web. 19 Jan 2021.
Vancouver:
Taei-Tehrani MR. Pseudo Random Arterial Modulation (PRAM): A Novel ASL Approach to Measure Flow and Blood Transit Times. [Internet] [Doctoral dissertation]. Columbia University; 2012. [cited 2021 Jan 19].
Available from: https://doi.org/10.7916/D88S4WWC.
Council of Science Editors:
Taei-Tehrani MR. Pseudo Random Arterial Modulation (PRAM): A Novel ASL Approach to Measure Flow and Blood Transit Times. [Doctoral Dissertation]. Columbia University; 2012. Available from: https://doi.org/10.7916/D88S4WWC

Columbia University
15.
Atanasova, Iliyana.
Non-contrast Magnetic Resonance Angiography for Evaluation of Peripheral Arterial Disease.
Degree: 2012, Columbia University
URL: https://doi.org/10.7916/D89W0NW9
► Peripheral arterial disease (PAD) is a major cause of morbidity and mortality in the USA with an estimated prevalence of up to 20% in those…
(more)
▼ Peripheral arterial disease (PAD) is a major cause of morbidity and mortality in the USA with an estimated prevalence of up to 20% in those over 75 years. Vascular disease and kidney impairment frequently coexist; prevalence of moderate to severe renal dysfunction in PAD patients is estimated at 27-36%. Knowledge of location, severity, and extent of PAD is imperative for accurate diagnosis and treatment planning. However, all established imaging modalities that are routinely used for treatment planning are contra-indicated in kidney disease patients. Contrast-enhanced x-ray and CT angiography are unsafe due to exposure to nephrotoxic contrast material and ionizing radiation. Recently, the FDA has also warned against the use of gadolinium-enhanced MRA (Gd-MRA) due to evidence that gadolinium could trigger a life-threatening condition known as nephrogenic systemic fibrosis (NSF) in patients with moderate to severe kidney dysfunction. There is a clinical need to develop vascular imaging techniques that are safe in patients with coexisting PAD and renal insufficiency. The focus of this thesis was the development of a non-contrast alternative to Gd-MRA for imaging of peripheral vessels from renal to pedal arteries with MRI. A new imaging sequence for non-contrast visualization of the abdominal and pelvic arteries was designed, implemented, and validated in a small cohort of PAD patients against Gd-MRA. In addition, an existing fast spin-echo based technique for unenhanced imaging of the lower extremities was optimized for improved performance in a clinical setting.
Subjects/Keywords: Diagnostic imaging; Biomedical engineering
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Atanasova, I. (2012). Non-contrast Magnetic Resonance Angiography for Evaluation of Peripheral Arterial Disease. (Doctoral Dissertation). Columbia University. Retrieved from https://doi.org/10.7916/D89W0NW9
Chicago Manual of Style (16th Edition):
Atanasova, Iliyana. “Non-contrast Magnetic Resonance Angiography for Evaluation of Peripheral Arterial Disease.” 2012. Doctoral Dissertation, Columbia University. Accessed January 19, 2021.
https://doi.org/10.7916/D89W0NW9.
MLA Handbook (7th Edition):
Atanasova, Iliyana. “Non-contrast Magnetic Resonance Angiography for Evaluation of Peripheral Arterial Disease.” 2012. Web. 19 Jan 2021.
Vancouver:
Atanasova I. Non-contrast Magnetic Resonance Angiography for Evaluation of Peripheral Arterial Disease. [Internet] [Doctoral dissertation]. Columbia University; 2012. [cited 2021 Jan 19].
Available from: https://doi.org/10.7916/D89W0NW9.
Council of Science Editors:
Atanasova I. Non-contrast Magnetic Resonance Angiography for Evaluation of Peripheral Arterial Disease. [Doctoral Dissertation]. Columbia University; 2012. Available from: https://doi.org/10.7916/D89W0NW9

Columbia University
16.
Cohen, Ouri.
In-Vivo Three Dimensional Proton Hadamard Spectroscopic Imaging in the Human Brain.
Degree: 2013, Columbia University
URL: https://doi.org/10.7916/D8639X3V
► Magnetic resonance spectroscopic imaging (MRSI) is a useful tool for obtaining information on the biochemical processes underlying various pathologies. A widely used multi-voxel localization method…
(more)
▼ Magnetic resonance spectroscopic imaging (MRSI) is a useful tool for obtaining information on the biochemical processes underlying various pathologies. A widely used multi-voxel localization method is chemical shift imaging (CSI) which uses gradients for phase encoding. Although simple to implement, low in specific absorption rate (SAR) and immune to chemical shift displacement (CSD), it also suffers from some well known drawbacks caused by its sinc-shaped point spread function (PSF). This results in loss of both signal-to-noise ratio (SNR) as well as localization, an effect that is exacerbated at low resolutions. In contrast, an alternative localization method, Hadamard spectroscopic imaging (HSI) benefits from a theoretically ideal PSF and consequently does not suffer from these drawbacks. In this work we exploit the theoretically ideal PSF of HSI encoding to develop a novel three dimensional (3D) multi-voxel MR localization method based on transverse HSI (T-HSI). The advantages of T HSI are that unlike gradient phase-encoding: (i) the volume of interest (VOI) does not need to be smaller than the field-of-view to prevent aliasing; (ii) the number of partitions in each direction can be small, 8, 4 or even 2 at no cost in PSF; (iii) the VOI does not have to be contiguous; and (iv) the voxel profile depends on the available B1 and pulse synthesis paradigm and can therefore, at least theoretically, approach "ideal" "1" inside and "0" elsewhere. Clinical utility of the new method is shown by spectra obtained from the brain of a healthy volunteer. The benefits of T-HSI are demonstrated by a quantitative comparison to CSI of the SNR and localization in a phantom in both one and three dimensions at clinical resolutions. A novel matrix formalism is used to quantify the impact of non-ideal flip angles on T-HSI. The superior PSF of T-HSI is then used to demonstrate the feasibility of scanning regions near or on the skull while limiting the impact of lipid contamination and obtaining quantifiable spectra. A comparison to spectra obtained using CSI is shown for a healthy volunteer. The new method is also used in a clinical pathology: to scan multiple sclerosis (MS) lesions occurring near the skull. To maintain the benefits provided by the PSF of HSI at higher fields, despite its susceptibility to CSD, a additional hybrid sequence is also developed that limits both the SAR and the CSD, regardless of the size of the VOI. A comparison to CSI in a phantom and in-vivo is carried out and spectra obtained from the brain of a healthy volunteer at 3T are shown. Finally, future research avenues involving extension of this research to ultra high fields (7T) are discussed and possible clinical uses are described.
Subjects/Keywords: Biomedical engineering; Diagnostic imaging
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Cohen, O. (2013). In-Vivo Three Dimensional Proton Hadamard Spectroscopic Imaging in the Human Brain. (Doctoral Dissertation). Columbia University. Retrieved from https://doi.org/10.7916/D8639X3V
Chicago Manual of Style (16th Edition):
Cohen, Ouri. “In-Vivo Three Dimensional Proton Hadamard Spectroscopic Imaging in the Human Brain.” 2013. Doctoral Dissertation, Columbia University. Accessed January 19, 2021.
https://doi.org/10.7916/D8639X3V.
MLA Handbook (7th Edition):
Cohen, Ouri. “In-Vivo Three Dimensional Proton Hadamard Spectroscopic Imaging in the Human Brain.” 2013. Web. 19 Jan 2021.
Vancouver:
Cohen O. In-Vivo Three Dimensional Proton Hadamard Spectroscopic Imaging in the Human Brain. [Internet] [Doctoral dissertation]. Columbia University; 2013. [cited 2021 Jan 19].
Available from: https://doi.org/10.7916/D8639X3V.
Council of Science Editors:
Cohen O. In-Vivo Three Dimensional Proton Hadamard Spectroscopic Imaging in the Human Brain. [Doctoral Dissertation]. Columbia University; 2013. Available from: https://doi.org/10.7916/D8639X3V

Columbia University
17.
Montejo, Ludguier.
Computational Methods For The Diagnosis of Rheumatoid Arthritis With Diffuse Optical Tomography.
Degree: 2014, Columbia University
URL: https://doi.org/10.7916/D8NS0S0C
► Diffuse optical tomography (DOT) is an imaging technique where near infrared (NIR) photons are used to probe biological tissue. DOT allows for the recovery of…
(more)
▼ Diffuse optical tomography (DOT) is an imaging technique where near infrared (NIR) photons are used to probe biological tissue. DOT allows for the recovery of three-dimensional maps of tissue optical properties, such as tissue absorption and scattering coefficients. The application of DOT as a tool to aid in the diagnosis of rheumatoid arthritis (RA) is explored in this work. Algorithms for improving the image reconstruction process and for enhancing the clinical value of DOT images are presented in detail. The clinical data considered in this work consists of 99 fingers from subjects with RA and 120 fingers from healthy subjects. DOT scans of the proximal interphalangeal (PIP) joint of each finger is performed with modulation frequencies of 0, 300, and 600 MHz.
A computer-aided diagnosis (CAD) framework for extracting heuristic features from DOT images and a method for using these same features to classify each joint as affected or not affected by RA is presented. The framework is applied to the clinical data and results are discussed in detail. Then, an algorithm for recovering the optical properties of biological media using the simplified spherical harmonics (SPN) light propagation model is presented. The computational performance of the algorithm is analyzed and reported. Finally, the SPN reconstruction algorithm is applied to clinical data of subjects with RA and the resulting images are analyzed with the CAD framework.
As the first part of the CAD framework, heuristic image features are extracted from the absorption and the scattering coefficient images using multiple compression and dimensionality reduction techniques. Overall, 594 features are extracted from the images of each joint. Then, machine-learning techniques are used to evaluate the ability to discriminate between images of joints with RA and images of healthy joints. An evolution-strategy optimization algorithm is developed to evaluate the classification strength of each feature and to find the multidimensional feature combination that results in optimal classification accuracy. Classification is performed with k-nearest neighbors (KNN), linear (LDA) and quadratic discriminate analysis (QDA), self-organizing maps (SOM), or support vector machines (SVM). Classification accuracy is evaluated based on diagnostic sensitivity and specificity values.
Strong evidence is presented that suggest there are clear differences between the tissue optical parameters of joints with RA and joints without RA. It is first shown that data obtained at 600 MHz leads to better classification results than data obtained at 300 and 0 MHz. Analysis of each extracted feature shows that DOT images of subjects with RA are statistically different (p < 0.05) from images of subjects without RA for over 90% of the features. Evidence shows that subjects with RA that do not have detectable signs of erosion, effusion, or synovitis (i.e. asymptomatic subjects) in MRI and US images have optical profiles similar to subjects who do have signs of erosion, effusion, or…
Subjects/Keywords: Biomedical engineering; Diagnostic imaging
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APA (6th Edition):
Montejo, L. (2014). Computational Methods For The Diagnosis of Rheumatoid Arthritis With Diffuse Optical Tomography. (Doctoral Dissertation). Columbia University. Retrieved from https://doi.org/10.7916/D8NS0S0C
Chicago Manual of Style (16th Edition):
Montejo, Ludguier. “Computational Methods For The Diagnosis of Rheumatoid Arthritis With Diffuse Optical Tomography.” 2014. Doctoral Dissertation, Columbia University. Accessed January 19, 2021.
https://doi.org/10.7916/D8NS0S0C.
MLA Handbook (7th Edition):
Montejo, Ludguier. “Computational Methods For The Diagnosis of Rheumatoid Arthritis With Diffuse Optical Tomography.” 2014. Web. 19 Jan 2021.
Vancouver:
Montejo L. Computational Methods For The Diagnosis of Rheumatoid Arthritis With Diffuse Optical Tomography. [Internet] [Doctoral dissertation]. Columbia University; 2014. [cited 2021 Jan 19].
Available from: https://doi.org/10.7916/D8NS0S0C.
Council of Science Editors:
Montejo L. Computational Methods For The Diagnosis of Rheumatoid Arthritis With Diffuse Optical Tomography. [Doctoral Dissertation]. Columbia University; 2014. Available from: https://doi.org/10.7916/D8NS0S0C

Columbia University
18.
Jia, Jingfei.
Fast Radiative-Transfer-Equation-Based Image Reconstruction Algorithms for Non-Contact Diffuse Optical Tomography Systems.
Degree: 2015, Columbia University
URL: https://doi.org/10.7916/D8KD1X4S
► It is well known that the radiative transfer equation (RTE) is the most accurate deterministic light propagation model employed in diffuse optical tomography (DOT). RTE-based…
(more)
▼ It is well known that the radiative transfer equation (RTE) is the most accurate deterministic light propagation model employed in diffuse optical tomography (DOT). RTE-based algorithms provide more accurate tomographic results than codes that rely on the diffusion equation (DE), which is an approximation to the RTE, in scattering dominant media. However, RTE based DOT (RTE-DOT) has limited utility in practice due to its high computational cost and lack of support for general non-contact imaging systems. In this dissertation, I developed fast reconstruction algorithms for RTE-based DOT (RTE-DOT), which consists of three independent components: an efficient linear solver for forward problems, an improved optimization solver for inverse problem, and the first light propagation model in free space that fully considers the angular dependency, which can provide a suitable measurement operator for RTE-DOT. This algorithm is validated and evaluated with numerical experiments and clinical data. According to these studies, the novel reconstruction algorithm is up to 30 times faster than traditional reconstruction techniques, while achieving comparable reconstruction accuracy.
Subjects/Keywords: Biomedical engineering; Diagnostic imaging
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APA (6th Edition):
Jia, J. (2015). Fast Radiative-Transfer-Equation-Based Image Reconstruction Algorithms for Non-Contact Diffuse Optical Tomography Systems. (Doctoral Dissertation). Columbia University. Retrieved from https://doi.org/10.7916/D8KD1X4S
Chicago Manual of Style (16th Edition):
Jia, Jingfei. “Fast Radiative-Transfer-Equation-Based Image Reconstruction Algorithms for Non-Contact Diffuse Optical Tomography Systems.” 2015. Doctoral Dissertation, Columbia University. Accessed January 19, 2021.
https://doi.org/10.7916/D8KD1X4S.
MLA Handbook (7th Edition):
Jia, Jingfei. “Fast Radiative-Transfer-Equation-Based Image Reconstruction Algorithms for Non-Contact Diffuse Optical Tomography Systems.” 2015. Web. 19 Jan 2021.
Vancouver:
Jia J. Fast Radiative-Transfer-Equation-Based Image Reconstruction Algorithms for Non-Contact Diffuse Optical Tomography Systems. [Internet] [Doctoral dissertation]. Columbia University; 2015. [cited 2021 Jan 19].
Available from: https://doi.org/10.7916/D8KD1X4S.
Council of Science Editors:
Jia J. Fast Radiative-Transfer-Equation-Based Image Reconstruction Algorithms for Non-Contact Diffuse Optical Tomography Systems. [Doctoral Dissertation]. Columbia University; 2015. Available from: https://doi.org/10.7916/D8KD1X4S

University of California – San Francisco
19.
Kuo, Wesley.
Binding Kinetics of Cisplatin with Ion-exchange Resins.
Degree: Biomedical Imaging, 2016, University of California – San Francisco
URL: http://www.escholarship.org/uc/item/4wq6f15t
► AbstractObjective: Localized chemotherapy can be more effective at treating cancers than traditional chemotherapy methods. Increased dosage leads to increased systemic toxicity, a critical issue that…
(more)
▼ AbstractObjective: Localized chemotherapy can be more effective at treating cancers than traditional chemotherapy methods. Increased dosage leads to increased systemic toxicity, a critical issue that must be addressed. The ChemoFilter - a temporarily deployable, endovascular device - aims to extract chemotherapeutic agents from the bloodstream in order to reduce adverse side effects in other areas of the body. In this study, we report the binding effectiveness of ion-exchange resins with cisplatin, a commonly administered chemotherapeutic.Materials and Methods: All experiments were conducted in vitro using cisplatin in distilled water and phosphate buffered saline. Ion-exchange resins (Dowex 50Wx2, Amberlite FPC22, Tulsion T-66, Amberlite IRC, Purolite S930/950) were tested in solution individually and the total amount of free cisplatin in solution was quantified using ultraviolet-visible spectroscopy and inductively coupled plasma mass spectroscopy.Results: Quantification of cisplatin using UV-visible methods demonstrated that strong acid cation exchangers perform exceptionally well in saline solutions, removing over 90% of free cisplatin within one minute. The concentration of free cisplatin did not drop when reacted with strong cation exchangers in water. Weak acid cation exchangers and chelating resins also displayed no binding of cisplatin in PBS. Assessing the performance of the strong cation exchange resin, Dowex 50Wx2, using ICP-MS showed that ion exchange filtration was comparable in both water and PBS.Conclusion: The current effectiveness of localized chemotherapy is limited by its corresponding increased systemic toxicity. The ChemoFilter seeks to mitigate the effects of chemotherapeutics on non-targeted areas of the body by extracting or inactivating the chemotherapy agents that pass through it. Our benchtop OPDA method of quantifying cisplatin in solution indicated that strong acid cation exchangers were exceptionally well-suited to the task. However, quantification using ICP-MS revealed that our previous UV-visible method of cisplatin quantification was not compatible with ion exchange resin studies and that these resins may not be very useful at fulfilling the ChemoFilter’s objective of removing cisplatin from solution.
Subjects/Keywords: Biomedical engineering; Medical imaging
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APA (6th Edition):
Kuo, W. (2016). Binding Kinetics of Cisplatin with Ion-exchange Resins. (Thesis). University of California – San Francisco. Retrieved from http://www.escholarship.org/uc/item/4wq6f15t
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Kuo, Wesley. “Binding Kinetics of Cisplatin with Ion-exchange Resins.” 2016. Thesis, University of California – San Francisco. Accessed January 19, 2021.
http://www.escholarship.org/uc/item/4wq6f15t.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Kuo, Wesley. “Binding Kinetics of Cisplatin with Ion-exchange Resins.” 2016. Web. 19 Jan 2021.
Vancouver:
Kuo W. Binding Kinetics of Cisplatin with Ion-exchange Resins. [Internet] [Thesis]. University of California – San Francisco; 2016. [cited 2021 Jan 19].
Available from: http://www.escholarship.org/uc/item/4wq6f15t.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Kuo W. Binding Kinetics of Cisplatin with Ion-exchange Resins. [Thesis]. University of California – San Francisco; 2016. Available from: http://www.escholarship.org/uc/item/4wq6f15t
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Florida
20.
Menon, Kannan M.
Design of an Efficient Framework to Improve the Outcomes and Usability of a Clinical Diffusion MRI Protocol.
Degree: PhD, Biomedical Engineering, 2019, University of Florida
URL: https://ufdc.ufl.edu/UFE0054328
► Diffusion MRI is an essential imaging protocol used in clinics on a daily basis. It serves an important role in the diagnosis and localization of…
(more)
▼ Diffusion MRI is an essential
imaging protocol used in clinics on a daily basis. It serves an important role in the diagnosis and localization of various neuropathologies such as Stroke, Dementia and Traumatic Brain Injury (TBI) among others. The depth of information that can be revealed from this methodology aids Physicians in making essential decisions such as designing a treatment strategy or selecting the choice of drug for a given diseased state.
Advisors/Committee Members: Forder,John R (committee chair), Vemuri,Baba C (committee member), Entezari,Alireza (committee member).
Subjects/Keywords: biomedical – imaging – medicine – mri – signals
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APA (6th Edition):
Menon, K. M. (2019). Design of an Efficient Framework to Improve the Outcomes and Usability of a Clinical Diffusion MRI Protocol. (Doctoral Dissertation). University of Florida. Retrieved from https://ufdc.ufl.edu/UFE0054328
Chicago Manual of Style (16th Edition):
Menon, Kannan M. “Design of an Efficient Framework to Improve the Outcomes and Usability of a Clinical Diffusion MRI Protocol.” 2019. Doctoral Dissertation, University of Florida. Accessed January 19, 2021.
https://ufdc.ufl.edu/UFE0054328.
MLA Handbook (7th Edition):
Menon, Kannan M. “Design of an Efficient Framework to Improve the Outcomes and Usability of a Clinical Diffusion MRI Protocol.” 2019. Web. 19 Jan 2021.
Vancouver:
Menon KM. Design of an Efficient Framework to Improve the Outcomes and Usability of a Clinical Diffusion MRI Protocol. [Internet] [Doctoral dissertation]. University of Florida; 2019. [cited 2021 Jan 19].
Available from: https://ufdc.ufl.edu/UFE0054328.
Council of Science Editors:
Menon KM. Design of an Efficient Framework to Improve the Outcomes and Usability of a Clinical Diffusion MRI Protocol. [Doctoral Dissertation]. University of Florida; 2019. Available from: https://ufdc.ufl.edu/UFE0054328

University of Oxford
21.
Woods, Joseph.
Time-efficient methods for non-invasive brain blood flow imaging using arterial spin labelling MRI.
Degree: PhD, 2019, University of Oxford
URL: http://ora.ox.ac.uk/objects/uuid:d56e1d6b-551d-4a54-9b6e-be390fdcd757
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.791666
► Accurate knowledge of brain tissue perfusion and clear visualisation of cerebral arteries are of great interest for the diagnosis and research of a range of…
(more)
▼ Accurate knowledge of brain tissue perfusion and clear visualisation of cerebral arteries are of great interest for the diagnosis and research of a range of diseases and conditions such as stroke, dementia, Moyamoya, and cancer, as well as in drug development. 15O-H20 PET imaging is considered the gold standard for measuring cerebral blood flow (CBF), while contrast-enhanced x-ray digital subtraction angiography is the gold standard for visualising cerebral arteries. However, both methods use ionising radiation and injectable contrast agents so carry some risks to the patient and are not appropriate for longitudinal monitoring or research. There is growing interest in arterial spin labelling (ASL) magnetic resonance imaging (MRI), which uses magnetically labelled blood as an endogenous and freely diffusible tracer and can be flexibly used to visualise the arterial tree as well as to measure CBF. However, ASL is an intrinsically low SNR technique, requiring signal averaging and long scan times. The main aim of this thesis is to improve the time-efficiency of ASL MRI perfusion and angiographic scans, increasing the accuracy and SNR of CBF measurements and vessel depiction in clinically relevant scan times. First, a statistical framework was developed and validated for optimising multi- delay ASL perfusion protocol timings to improve the accuracy of CBF and arterial transit time measurements. This flexible framework can be targeted to improve the accuracy of specific parameters and provides a more informed method for designing ASL protocols. Next, this framework was used to optimise and objectively compare a range of existing pseudo-continuous ASL (PCASL) perfusion protocol designs, including time- encoded preparations, from the literature and to explore novel protocol designs. These comparisons allowed the advantages and disadvantages of each approach to be explored, and recommendations about the best ASL experimental designs to be made. Finally, the benefits of time-encoded PCASL preparations for ASL angiography were investigated. Angiography visualises the pass-through of labelled blood, in contrast to perfusion imaging which relies on the accumulation of labelled blood in tissue, and so the short label durations used in time-encoded PCASL have a greatly reduced impact on the magnitude of the ASL signal. A variable flip-angle approach was also used to remove signal discontinuities and demonstrate a significant SNR improvement over conventional PCASL angiography.
Subjects/Keywords: Magnetic resonance imaging; Biomedical Engineering
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Woods, J. (2019). Time-efficient methods for non-invasive brain blood flow imaging using arterial spin labelling MRI. (Doctoral Dissertation). University of Oxford. Retrieved from http://ora.ox.ac.uk/objects/uuid:d56e1d6b-551d-4a54-9b6e-be390fdcd757 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.791666
Chicago Manual of Style (16th Edition):
Woods, Joseph. “Time-efficient methods for non-invasive brain blood flow imaging using arterial spin labelling MRI.” 2019. Doctoral Dissertation, University of Oxford. Accessed January 19, 2021.
http://ora.ox.ac.uk/objects/uuid:d56e1d6b-551d-4a54-9b6e-be390fdcd757 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.791666.
MLA Handbook (7th Edition):
Woods, Joseph. “Time-efficient methods for non-invasive brain blood flow imaging using arterial spin labelling MRI.” 2019. Web. 19 Jan 2021.
Vancouver:
Woods J. Time-efficient methods for non-invasive brain blood flow imaging using arterial spin labelling MRI. [Internet] [Doctoral dissertation]. University of Oxford; 2019. [cited 2021 Jan 19].
Available from: http://ora.ox.ac.uk/objects/uuid:d56e1d6b-551d-4a54-9b6e-be390fdcd757 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.791666.
Council of Science Editors:
Woods J. Time-efficient methods for non-invasive brain blood flow imaging using arterial spin labelling MRI. [Doctoral Dissertation]. University of Oxford; 2019. Available from: http://ora.ox.ac.uk/objects/uuid:d56e1d6b-551d-4a54-9b6e-be390fdcd757 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.791666

Rutgers University
22.
Mohabir, Justin Heeralaal.
Knee cartilage segmentation of ultrasound images using convolutional neural networks and local phase enhancement.
Degree: MS, Knee Cartilage, 2020, Rutgers University
URL: https://rucore.libraries.rutgers.edu/rutgers-lib/64045/
► Osteoarthritis (OA) is a chronic disorder that results from the inflammation of body joints and the degradation of cartilage. The most prominent form of OA…
(more)
▼ Osteoarthritis (OA) is a chronic disorder that results from the inflammation of body joints and the degradation of cartilage. The most prominent form of OA is knee OA, where the cartilage between the femur and tibia degrades from regular use. To measure the progression of knee OA in patients, clinicians use a metric of cartilage thickness known as Joint Space Width (JSW) to see how much cartilage is degraded over time. The most common method of measuring JSW is to perform a planar X-ray on the knee and manually measure the space between the joints from that image. This, however, gives patients a dose of ionizing radiation. Magnetic Resonance (MR)
imaging and Ultrasound (US) have arisen as alternatives to
imaging knee cartilage. MR
imaging is reserved to research settings due to the expensive operation. This leaves US as the main alternative to show promise from clinical studies but has limitations such as noise and artifacts that make segmentation of the knee cartilage within images difficult to segment manually. A previous study has shown that enhancing images prior to segmentation can allow a more accurate segmentation. This thesis investigated the efficacy of using different Convolutional Neural Network (CNN) architectures to segment knee cartilage from US images, as well as the effect of enhancing the images prior to segmentation from the CNNs compared to a Random Walker (RW) algorithm.
The CNN architectures used in this study are: U-Net, Stacked U-Net and W-Net. Each of these architectures were trained by either B-mode images, local phase enhanced images, or an early-stage combination of both the B-mode and enhanced images. The 150-image training set of data used was augmented to artificially increase the amount of training images to improve the robustness and to prevent overfitting. 10-fold cross-validation was performed on each combination of CNN architecture and input type to prevent outliers.
Validation was performed on each of the CNNs generated by comparison against a manual segmentation of the US images using the Dice Similarity Coefficient (DSC). Validation was performed on 50 images from a similar dataset used to train the CNNs and a second set of 50 images from a different US system. The average DSC for the U-Net, Stacked U-Net and W-Net were: 0.8566, 0.8289 and 0.8675 in the similar dataset and 0.779, 0.7185 and 0.772 in the different dataset, respectively. The average DSC for the B-Mode, enhanced, and combined input types were: 0.8071, 0.8552 and 0.8908 in the similar dataset and 0.6869, 0.7756 and 0.807 in the different dataset, respectively. Compared to a RW algorithm, 53% of U-Nets, 67% of Stacked U-Nets, and 70% of W-Nets had significantly (p>0.05) higher average DSCs. 30% of B-Mode networks, 77% of enhanced image networks and 83% combined image networks had significantly higher DSCs. This study presents an automated US cartilage segmentation method using CNNs. The results presented show significant improvements in segmentation using local phase enhancement instead of an unaltered B-Mode US…
Advisors/Committee Members: Hacihaliloglu, Ilker (chair), Pierce, Mark (internal member), Boustany, Nada (internal member), School of Graduate Studies.
Subjects/Keywords: Knee – Imaging; Biomedical Engineering
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APA (6th Edition):
Mohabir, J. H. (2020). Knee cartilage segmentation of ultrasound images using convolutional neural networks and local phase enhancement. (Masters Thesis). Rutgers University. Retrieved from https://rucore.libraries.rutgers.edu/rutgers-lib/64045/
Chicago Manual of Style (16th Edition):
Mohabir, Justin Heeralaal. “Knee cartilage segmentation of ultrasound images using convolutional neural networks and local phase enhancement.” 2020. Masters Thesis, Rutgers University. Accessed January 19, 2021.
https://rucore.libraries.rutgers.edu/rutgers-lib/64045/.
MLA Handbook (7th Edition):
Mohabir, Justin Heeralaal. “Knee cartilage segmentation of ultrasound images using convolutional neural networks and local phase enhancement.” 2020. Web. 19 Jan 2021.
Vancouver:
Mohabir JH. Knee cartilage segmentation of ultrasound images using convolutional neural networks and local phase enhancement. [Internet] [Masters thesis]. Rutgers University; 2020. [cited 2021 Jan 19].
Available from: https://rucore.libraries.rutgers.edu/rutgers-lib/64045/.
Council of Science Editors:
Mohabir JH. Knee cartilage segmentation of ultrasound images using convolutional neural networks and local phase enhancement. [Masters Thesis]. Rutgers University; 2020. Available from: https://rucore.libraries.rutgers.edu/rutgers-lib/64045/

Rutgers University
23.
Patel, Hridayi, 1997-.
Improved automatic bone segmentation using large-scale simulated ultrasound data to segment real ultrasound bone surface data.
Degree: MS, Ultrasound segmentation, 2020, Rutgers University
URL: https://rucore.libraries.rutgers.edu/rutgers-lib/64047/
► Automatic segmentation of bone surfaces from ultrasound images is of great interest in the ultrasound-guided computer assisted orthopedic surgery field. These automatic segmentations help the…
(more)
▼ Automatic segmentation of bone surfaces from ultrasound images is of great interest in the ultrasound-guided computer assisted orthopedic surgery field. These automatic segmentations help the system locate where the bone surface is in the image which can allow for proper surgical manipulation. Methods that involve using image processing tools have previously been used to perform the segmentations however, they have faced problems due to the noise and various
imaging artifacts associated with ultrasound data. Most recently, methods based on deep learning have achieved promising results. However, a drawback is that these methods require large number of training dataset. Therefore, new methods which can overcome these drawbacks need to be investigated in order to accurately segment bone surfaces from real ultrasound data.
This thesis introduces the concept of training the deep learning methods with large-scale simulated bone ultrasound data and investigating how using large-scale simulated data along with limited real ultrasound data affects the segmentation performance of the deep learning network. A transfer learning approach and using a training dataset consisting of both real and simulated ultrasound bone surface data was applied for the investigation. We show that by using simulated bone ultrasound data, the success of traditional deep learning methods increases compared to using small-scale real ultrasound data only.
Data used in the study consisted of real ultrasound data collected from different subjects and utilizing 3D Slicer and PLUS for generating simulate ultrasound data. Various networks were trained in order to determine how well the network of a certain dataset is able to perform automatic segmentations on the same type of data. Additionally, networks trained with both large-scale simulated US data and limited real ultrasound data were trained and tested on real ultrasound data to determine if using large-scale simulated data improves network performance. The automatic segmentations of the neural networks were compared against manual segmentations of the same data by calculating the Sorensen- Dice Coefficient and Average Euclidean Distance. Results of the thesis show that using large- scale simulated ultrasound data can be used to train a neural network to segment real ultrasound data if both types of datasets are used together to develop the network.
Advisors/Committee Members: Hacihaliloglu, Ilker (chair), Boustany, Nada (internal member), Pierce, Mark (internal member), School of Graduate Studies.
Subjects/Keywords: Skeleton – Imaging; Biomedical Engineering
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APA (6th Edition):
Patel, Hridayi, 1. (2020). Improved automatic bone segmentation using large-scale simulated ultrasound data to segment real ultrasound bone surface data. (Masters Thesis). Rutgers University. Retrieved from https://rucore.libraries.rutgers.edu/rutgers-lib/64047/
Chicago Manual of Style (16th Edition):
Patel, Hridayi, 1997-. “Improved automatic bone segmentation using large-scale simulated ultrasound data to segment real ultrasound bone surface data.” 2020. Masters Thesis, Rutgers University. Accessed January 19, 2021.
https://rucore.libraries.rutgers.edu/rutgers-lib/64047/.
MLA Handbook (7th Edition):
Patel, Hridayi, 1997-. “Improved automatic bone segmentation using large-scale simulated ultrasound data to segment real ultrasound bone surface data.” 2020. Web. 19 Jan 2021.
Vancouver:
Patel, Hridayi 1. Improved automatic bone segmentation using large-scale simulated ultrasound data to segment real ultrasound bone surface data. [Internet] [Masters thesis]. Rutgers University; 2020. [cited 2021 Jan 19].
Available from: https://rucore.libraries.rutgers.edu/rutgers-lib/64047/.
Council of Science Editors:
Patel, Hridayi 1. Improved automatic bone segmentation using large-scale simulated ultrasound data to segment real ultrasound bone surface data. [Masters Thesis]. Rutgers University; 2020. Available from: https://rucore.libraries.rutgers.edu/rutgers-lib/64047/

University of Oxford
24.
Fisher, Katherine Rose.
Devising new biomedical imaging applications for metallodrugs based on an improved understanding of their electronic and magnetic properties.
Degree: PhD, 2020, University of Oxford
URL: http://ora.ox.ac.uk/objects/uuid:1b8b99fc-b0f7-4094-a5c0-5c6b1e8a55cc
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.816610
► Ligand field anisotropy plays a key role in defining the spectroscopic properties of lanthanide complexes. Changes to the local ligand field can have profound consequences…
(more)
▼ Ligand field anisotropy plays a key role in defining the spectroscopic properties of lanthanide complexes. Changes to the local ligand field can have profound consequences for the NMR, luminescence and EPR properties of lanthanide ions with inherent anisotropy. In this project ligand field effects are shown to be significant for even Gd(III) complexes, where the ground state of the free ion has an isotropic electron distribution. In these systems, changes to the ligand field and the axial donor are shown to have dramatic effects on the form of the EPR spectrum. These can be rationalized through considering the donor set. A number of EPR techniques were used to characterize the systems: CW EPR and pulsed PEANUT measurements can be correlated with the splitting of the Ms states within the 8S ground state of Gd(III). These effects can also be seen for systems with broken symmetry and these variations, with relatively small changes to the local field, can provide useful information and aid in the development of new contrast media. There are also potential further applications for electron polarization agents for DNP MRI. This potential was explored using CW EPR of polymetallic lanthanide complexes and subsequent DNP NMR experiments. Whilst build-up of hyperpolarization could be observed, further development of these complexes is needed in order to surpass the current “gold-standard” and be translated for clinical practice.
Subjects/Keywords: Biomedical Imaging; Inorganic Chemistry
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Manager
APA (6th Edition):
Fisher, K. R. (2020). Devising new biomedical imaging applications for metallodrugs based on an improved understanding of their electronic and magnetic properties. (Doctoral Dissertation). University of Oxford. Retrieved from http://ora.ox.ac.uk/objects/uuid:1b8b99fc-b0f7-4094-a5c0-5c6b1e8a55cc ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.816610
Chicago Manual of Style (16th Edition):
Fisher, Katherine Rose. “Devising new biomedical imaging applications for metallodrugs based on an improved understanding of their electronic and magnetic properties.” 2020. Doctoral Dissertation, University of Oxford. Accessed January 19, 2021.
http://ora.ox.ac.uk/objects/uuid:1b8b99fc-b0f7-4094-a5c0-5c6b1e8a55cc ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.816610.
MLA Handbook (7th Edition):
Fisher, Katherine Rose. “Devising new biomedical imaging applications for metallodrugs based on an improved understanding of their electronic and magnetic properties.” 2020. Web. 19 Jan 2021.
Vancouver:
Fisher KR. Devising new biomedical imaging applications for metallodrugs based on an improved understanding of their electronic and magnetic properties. [Internet] [Doctoral dissertation]. University of Oxford; 2020. [cited 2021 Jan 19].
Available from: http://ora.ox.ac.uk/objects/uuid:1b8b99fc-b0f7-4094-a5c0-5c6b1e8a55cc ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.816610.
Council of Science Editors:
Fisher KR. Devising new biomedical imaging applications for metallodrugs based on an improved understanding of their electronic and magnetic properties. [Doctoral Dissertation]. University of Oxford; 2020. Available from: http://ora.ox.ac.uk/objects/uuid:1b8b99fc-b0f7-4094-a5c0-5c6b1e8a55cc ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.816610

University of Arizona
25.
Uthoff, Ross David.
Applications, Devices, and Methods for Smartphone-Based Medical Imaging Systems
.
Degree: 2019, University of Arizona
URL: http://hdl.handle.net/10150/636597
► As cancer rates continue to increase, new adjunctive tools are needed to augment the skills of clinicians to enable earlier detection and diagnosis, a key…
(more)
▼ As cancer rates continue to increase, new adjunctive tools are needed to augment the skills of clinicians to enable earlier detection and diagnosis, a key to reducing morbidity, mortality, and overall healthcare costs. Autofluorescence
imaging (AFI) and multispectral
imaging (MSI) systems have the potential to increase detection rates in oral cancer and skin cancer screening programs, respectively. With limited resources in many areas where cancer rates are highest, the devices should be low-cost for the opportunity to reach the most communities and easy-to-operate by healthcare providers of any skill level. Advances in 3d-printing, hardware, and software technologies enable low-cost, smartphone-based medical
imaging devices to be quickly developed and field tested. Integration of AFI, MSI, and polarized-white light (PWLI)
imaging modalities along with machine-learning-based image classification further extends the smartphone's capabilities. Additionally, the smartphone's data transmission abilities allow the upload of images to the cloud for remote examination by specialists through web-based platforms. Presented are designs and testing results for a number of low-cost, smartphone-based
imaging devices with feature sets and efficacies that rival higher-cost systems. A dual-view oral cancer screening device with remote specialist and convolutional neural network (CNN) classification achieved sensitivities, specificities, positive predictive values, and negative predictive values ranging from 81% to 94% compared to an on-site specialist's diagnosis. A second intraoral probe device improves on the previous by significantly reducing its cross-sectional area and adding a flexible section, improving patient comfort and access to significant oral cancer areas in the oropharynx and base of tongue. Lastly, two dermascopes utilizing MSI and PWLI are compared for skin cancer screening and erythema monitoring through chromophore mapping. As image databases are built and machine learning classification algorithms improve, these devices have the potential to transition from adjunctive to primary detection tools, reducing the number of biopsies and gold-standard histopathological analyses required.
Advisors/Committee Members: Liang, Rongguang (advisor), Gmitro, Art (committeemember), Kang, Dongkyun (committeemember).
Subjects/Keywords: autofluorescence imaging;
biomedical optics;
cancer screening;
multispectral imaging;
smartphone imaging
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Uthoff, R. D. (2019). Applications, Devices, and Methods for Smartphone-Based Medical Imaging Systems
. (Doctoral Dissertation). University of Arizona. Retrieved from http://hdl.handle.net/10150/636597
Chicago Manual of Style (16th Edition):
Uthoff, Ross David. “Applications, Devices, and Methods for Smartphone-Based Medical Imaging Systems
.” 2019. Doctoral Dissertation, University of Arizona. Accessed January 19, 2021.
http://hdl.handle.net/10150/636597.
MLA Handbook (7th Edition):
Uthoff, Ross David. “Applications, Devices, and Methods for Smartphone-Based Medical Imaging Systems
.” 2019. Web. 19 Jan 2021.
Vancouver:
Uthoff RD. Applications, Devices, and Methods for Smartphone-Based Medical Imaging Systems
. [Internet] [Doctoral dissertation]. University of Arizona; 2019. [cited 2021 Jan 19].
Available from: http://hdl.handle.net/10150/636597.
Council of Science Editors:
Uthoff RD. Applications, Devices, and Methods for Smartphone-Based Medical Imaging Systems
. [Doctoral Dissertation]. University of Arizona; 2019. Available from: http://hdl.handle.net/10150/636597

Columbia University
26.
Bouchard, Matthew Bryan.
2D and 3D high-speed multispectral optical imaging systems for in-vivo biomedical research.
Degree: 2014, Columbia University
URL: https://doi.org/10.7916/D8D798G5
► Functional optical imaging encompasses the use of optical imaging techniques to study living biological systems in their native environments. Optical imaging techniques are well-suited for…
(more)
▼ Functional optical imaging encompasses the use of optical imaging techniques to study living biological systems in their native environments. Optical imaging techniques are well-suited for functional imaging because they are minimally-invasive, use non ionizing radiation, and derive contrast from a wide range of biological molecules. Modern transgenic labeling techniques, active and inactive exogenous agents, and intrinsic sources of contrast provide specific and dynamic markers of in-vivo processes at subcellular resolution. A central challenge in building functional optical imaging systems is to acquire data at high enough spatial and temporal resolutions to be able to resolve the in-vivo process(es) under study. This challenge is particularly highlighted within neuroscience where considerable effort in the field has focused on studying the structural and functional relationships within complete neurovascular units in the living brain. Many existing functional optical techniques are limited in meeting this challenge by their imaging geometries, light source(s), and/or hardware implementations. In this thesis we describe the design, construction, and application of novel 2D and 3D optical imaging systems to address this central challenge with a specific focus on functional neuroimaging applications. The 2D system is an ultra-fast, multispectral, wide-field imaging system capable of imaging 7.5 times faster than existing technologies. Its camera-first design allows for the fastest possible image acquisition rates because it is not limited by synchronization challenges that have hindered previous multispectral systems. We present the development of this system from a bench top instrument to a portable, low-cost, modular, open source, laptop based instrument. The constructed systems can acquire multispectral images at >75 frames per second with image resolutions up to 512 x 512 pixels. This increased speed means that spectral analysis more accurately reflects the instantaneous state of tissues and allows for significantly improved tracking of moving objects. We describe 3 quantitative applications of these systems to in-vivo research and clinical studies of cortical imaging and calcium signaling in stem cells. The design and source code of the portable system was released to the greater scientific community to help make high-speed, multispectral imaging more accessible to a larger number of dynamic imaging applications, and to foster further development of the software package. The second system we developed is an entirely new, high-speed, 3D fluorescence microscopy platform called Laser-Scanning Intersecting Plane Tomography (L-SIPT). L-SIPT uses a novel combination of light-sheet illumination and off-axis detection to provide en-face 3D imaging of samples. L-SIPT allows samples to move freely in their native environments, enabling a range of experiments not possible with previous 3D optical imaging techniques. The constructed system is capable of acquiring 3D images at rates >20 volumes per second (VPS) with volume…
Subjects/Keywords: Brain – Imaging; Multispectral imaging; Three-dimensional imaging; Imaging systems in biology; Biomedical engineering
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Bouchard, M. B. (2014). 2D and 3D high-speed multispectral optical imaging systems for in-vivo biomedical research. (Doctoral Dissertation). Columbia University. Retrieved from https://doi.org/10.7916/D8D798G5
Chicago Manual of Style (16th Edition):
Bouchard, Matthew Bryan. “2D and 3D high-speed multispectral optical imaging systems for in-vivo biomedical research.” 2014. Doctoral Dissertation, Columbia University. Accessed January 19, 2021.
https://doi.org/10.7916/D8D798G5.
MLA Handbook (7th Edition):
Bouchard, Matthew Bryan. “2D and 3D high-speed multispectral optical imaging systems for in-vivo biomedical research.” 2014. Web. 19 Jan 2021.
Vancouver:
Bouchard MB. 2D and 3D high-speed multispectral optical imaging systems for in-vivo biomedical research. [Internet] [Doctoral dissertation]. Columbia University; 2014. [cited 2021 Jan 19].
Available from: https://doi.org/10.7916/D8D798G5.
Council of Science Editors:
Bouchard MB. 2D and 3D high-speed multispectral optical imaging systems for in-vivo biomedical research. [Doctoral Dissertation]. Columbia University; 2014. Available from: https://doi.org/10.7916/D8D798G5
27.
Shanmugam, Akshaya.
3d On-Sensor Lensless Fluorescence Imaging.
Degree: MS(M.S.), Electrical & Computer Engineering, 2012, U of Massachusetts : Masters
URL: http://scholarworks.umass.edu/theses/847
► Fluorescence microscopy has revolutionized medicine and biological science with its ability to study the behavior and chemical expressions of living cells. Fluorescent probes can…
(more)
▼ Fluorescence microscopy has revolutionized medicine and biological science with its ability to study the behavior and chemical expressions of living cells. Fluorescent probes can label cell components or cells of a particular type. Clinically the impact of fluorescence
imaging can be seen in the diagnosis of cancers, AIDS, and other blood related disorders.
Although fluorescence
imaging devices have been established as a vital tool in medicine, the size, cost, and complexity of fluorescence microscopes limits their use to central laboratories. The work described in this thesis overcomes these limitations by developing a low cost integrated fluorescence microscope so single use fluorescence microscopy assays can be developed. These assays will enable at-home testing, diagnostics in resource limited settings, and improved emergency medicine.
Advisors/Committee Members: Christopher Salthouse.
Subjects/Keywords: 3D fluorescence imaging; Contact imaging; lensless imaging; Bioimaging and Biomedical Optics; Biomedical; Biomedical Devices and Instrumentation; Signal Processing
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Shanmugam, A. (2012). 3d On-Sensor Lensless Fluorescence Imaging. (Masters Thesis). U of Massachusetts : Masters. Retrieved from http://scholarworks.umass.edu/theses/847
Chicago Manual of Style (16th Edition):
Shanmugam, Akshaya. “3d On-Sensor Lensless Fluorescence Imaging.” 2012. Masters Thesis, U of Massachusetts : Masters. Accessed January 19, 2021.
http://scholarworks.umass.edu/theses/847.
MLA Handbook (7th Edition):
Shanmugam, Akshaya. “3d On-Sensor Lensless Fluorescence Imaging.” 2012. Web. 19 Jan 2021.
Vancouver:
Shanmugam A. 3d On-Sensor Lensless Fluorescence Imaging. [Internet] [Masters thesis]. U of Massachusetts : Masters; 2012. [cited 2021 Jan 19].
Available from: http://scholarworks.umass.edu/theses/847.
Council of Science Editors:
Shanmugam A. 3d On-Sensor Lensless Fluorescence Imaging. [Masters Thesis]. U of Massachusetts : Masters; 2012. Available from: http://scholarworks.umass.edu/theses/847

UCLA
28.
Dushyanth, Anita.
Motion Correction in Orbital Imaging Using MRI Compatible Eye Tracker.
Degree: Biomedical Engineering, 2014, UCLA
URL: http://www.escholarship.org/uc/item/7c32r72f
► The body motion of patients during magnetic resonance imaging (MRI) causes significant artifacts in the reconstructed image. Artifacts are manifested as a motion induced blur…
(more)
▼ The body motion of patients during magnetic resonance imaging (MRI) causes significant artifacts in the reconstructed image. Artifacts are manifested as a motion induced blur and ghost repetitions of the moving structures, which obscure vital anatomical and pathological detail. The techniques that have been proposed for suppressing motion artifacts fall into two major categories. Realtime techniques that attempt to prevent the motion from corrupting the data by restricting the data acquisition times or motion of the patients, and post-processing techniques that use information embedded in the corrupted data to restore the image. The post-processing techniques usually demand an appropriate model of the motion that requires the parameters be determined in order to invert the data degradation process. However, motion is manifested differently depending on the time and duration it occurred during Magnetic Resonance (MR) data acquisition. Estimating motion parameters from such cases are heavily based on assumptions and the reconstructed image is compromised on either contrast or resolution. A major challenge in high resolution MR imaging of the orbit (eyeball and associated tissues in the eye socket) is image degradation by artifacts resulting from eye movements and eyelid blinks.In this thesis a novel method for motion correction has been developed by incorporating an optical sensor that detects these eye movements during MR scan acquisition without generating signal artifacts, and which is not affected by either the strong static magnetic field or the pulsed field gradients. Detection of the subjects eye movements and blinks is essential for determining the exact times during the MR scan when each such movement occurred.This thesis presents a method for refining orbital MRI techniques to compensate for the effects of blinking and fixation instability. It employs an eye tracker system to track eye/eyelid movements in the MRI studies of strabismus in humans that is based on infrared (IR) light reflection. It incorporates custom-fabricated optical fiber probes that illuminate the eye with low intensity infrared light, while eye/eyelid movements are detected by changes in ocular surface reflectance transmitted by another optical fiber cable coupled to a photodiode. Additionally, there is another light source that serves as a visible point target for ocular fixation during MRI scanning. The volunteer's eye movements are recorded simultaneously while the orbit is scanned using MRI. The output signal from the detector is amplified and synchronized in time with the MR acquired data. Image data corrupted by motion is flagged so that the affected data can be removed during image reconstruction. The purpose of this experiment is to outline experimental protocols for acquiring and correcting the above mentioned images in high quality, discuss these protocols from a wide range of perspectives, and finally present some observations on pilot data from volunteer subjects as well as patient with pathology. The MRI methodology developed…
Subjects/Keywords: Biomedical engineering; Eye Tracker; MRI; Orbital Imaging
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Dushyanth, A. (2014). Motion Correction in Orbital Imaging Using MRI Compatible Eye Tracker. (Thesis). UCLA. Retrieved from http://www.escholarship.org/uc/item/7c32r72f
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Dushyanth, Anita. “Motion Correction in Orbital Imaging Using MRI Compatible Eye Tracker.” 2014. Thesis, UCLA. Accessed January 19, 2021.
http://www.escholarship.org/uc/item/7c32r72f.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Dushyanth, Anita. “Motion Correction in Orbital Imaging Using MRI Compatible Eye Tracker.” 2014. Web. 19 Jan 2021.
Vancouver:
Dushyanth A. Motion Correction in Orbital Imaging Using MRI Compatible Eye Tracker. [Internet] [Thesis]. UCLA; 2014. [cited 2021 Jan 19].
Available from: http://www.escholarship.org/uc/item/7c32r72f.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Dushyanth A. Motion Correction in Orbital Imaging Using MRI Compatible Eye Tracker. [Thesis]. UCLA; 2014. Available from: http://www.escholarship.org/uc/item/7c32r72f
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Rochester Institute of Technology
29.
Riddle, R. Scott.
Retopologizing MRI and Diffusion Tensor Tractography Datasets for Real-time Interactivity.
Degree: MFA, Medical Illustration (CHST), 2016, Rochester Institute of Technology
URL: https://scholarworks.rit.edu/theses/9378
► Current technology allows MRI and other patient data to be translated into voxel-based 3D models for the purpose of visualization. However, these voxel models…
(more)
▼ Current technology allows MRI and other patient data to be translated into voxel-based 3D models for the purpose of visualization. However, these voxel models are extremely complex and are not suitable for rapid real-time manipulation. For true “on-the-fly” interactivity, polygon-based models must be hand-built using other methods and imported into a game engine.This project develops an algorithm to translate complex datasets into optimized models for real-time interactivity without sacrificing accuracy of the original
imaging modality. A working prototype, ready for integration into game engines, has been built with brain tumor data exported from OSIRIX1 and 3D Slicer2 via Mudbox3, retopologized in 3D Coat4 and re-imported to Maya5. White matter tracts detected by Diffusion Tensor Tractography are exported as volume models using 3D Slicer.The model has been integrated into the Unreal Development Kit (UDK)6 game engine to facilitate real-time interactivity across multiple platforms, including Mac, PC, Apple iOS, Google Android, Xbox 360, and SONY PlayStation. New techniques are being explored to automate and accelerate the process of retopologizing models.
1.Osirix – Advanced Open-Source PACS Workstation DICOM Viewer http://www.osirix-viewer.com/
2. 3D Slicer- A multi-platform, free and open source software package for visualization and medical image computing http://www.3dslicer.org
3.MudBox – Autodesk¨ Mudbox™ 3D digital sculpting and digital painting software http://usa.autodesk. com
4.3D Coat – Retopologizing and 3D sculpting software http://3d-coat.com
5.MAYA - Autodesk¨Maya¨ 3D animation software delivers an end-to-end creative workflow with compression tools for animation, modeling, simulation, visual effects, rendering, matchmoving, and compositing on a highly extensible production platform http://usa.autodesk.com
6.Unreal Engine 3 – a complete development framework for PCs, iOS, Xbox 360¨, and PlayStation¨ 3, providing a vast array of core technologies, content creation tools and support infrastructure http://www. unrealengine.com/
Advisors/Committee Members: James Perkins.
Subjects/Keywords: Biomedical; Brain; Imaging; Medical; Neurosurgery; Realtime
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Riddle, R. S. (2016). Retopologizing MRI and Diffusion Tensor Tractography Datasets for Real-time Interactivity. (Thesis). Rochester Institute of Technology. Retrieved from https://scholarworks.rit.edu/theses/9378
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Riddle, R Scott. “Retopologizing MRI and Diffusion Tensor Tractography Datasets for Real-time Interactivity.” 2016. Thesis, Rochester Institute of Technology. Accessed January 19, 2021.
https://scholarworks.rit.edu/theses/9378.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Riddle, R Scott. “Retopologizing MRI and Diffusion Tensor Tractography Datasets for Real-time Interactivity.” 2016. Web. 19 Jan 2021.
Vancouver:
Riddle RS. Retopologizing MRI and Diffusion Tensor Tractography Datasets for Real-time Interactivity. [Internet] [Thesis]. Rochester Institute of Technology; 2016. [cited 2021 Jan 19].
Available from: https://scholarworks.rit.edu/theses/9378.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Riddle RS. Retopologizing MRI and Diffusion Tensor Tractography Datasets for Real-time Interactivity. [Thesis]. Rochester Institute of Technology; 2016. Available from: https://scholarworks.rit.edu/theses/9378
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Purdue University
30.
Bentz, Brian Z.
In Vivo Optical Imaging for Targeted Drug Kinetics and Localization for Oral Surgery and Super-Resolution, Facilitated by Printed Phantoms.
Degree: 2017, Purdue University
URL: http://pqdtopen.proquest.com/#viewpdf?dispub=10274948
► Many human cancer cell types over-express folate receptors, and this provides an opportunity to develop targeted anti-cancer drugs. For these drugs to be effective,…
(more)
▼ Many human cancer cell types over-express folate receptors, and this provides an opportunity to develop targeted anti-cancer drugs. For these drugs to be effective, their kinetics must be well understood <i>in vivo</i> and in deep tissue where tumors occur. We demonstrate a method for imaging these parameters by incorporating a kinetic compartment model and fluorescence into optical diffusion tomography (ODT). The kinetics were imaged in a live mouse, and found to be in agreement with previous <i>in vitro</i> studies, demonstrating the validity of the method and its feasibility as an effective tool in preclinical drug development studies. Progress in developing optical imaging for biomedical applications requires customizable and often complex objects known as “phantoms” for testing and evaluation. We present new optical phantoms fabricated using inexpensive 3D printing methods with multiple materials, allowing for the placement of complex inhomogeneities in heterogeneous or anatomically realistic geometries, as opposed to previous phantoms which were limited to simple shapes formed by molds or machining. Furthermore, we show that Mie theory can be used to design the optical properties to match a target tissue. The phantom fabrication methods are versatile, can be applied to optical imaging methods besides diffusive imaging, and can be used in the calibration of live animal imaging data. Applications of diffuse optical imaging in the operating theater have been limited in part due to computational burden. We present an approach for the fast localization of arteries in the roof of the mouth that has the potential to reduce complications. Furthermore, we use the extracted position information to fabricate a custom surgical guide using 3D printing that could protect the arteries during surgery. The resolution of ODT is severely limited by the attenuation of high spatial frequencies. We present a super-resolution method achieved through the point localization of fluorescent inhomogeneities in a tissue-like scattering medium, and examine the localization uncertainty numerically and experimentally. Furthermore, we show numerical results for the localization of multiple fluorescent inhomogeneities by distinguishing them based on temporal characteristics. Potential applications include imaging neuron activation in the brain.
Subjects/Keywords: Biomedical engineering; Electrical engineering; Medical imaging; Optics
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Bentz, B. Z. (2017). In Vivo Optical Imaging for Targeted Drug Kinetics and Localization for Oral Surgery and Super-Resolution, Facilitated by Printed Phantoms. (Thesis). Purdue University. Retrieved from http://pqdtopen.proquest.com/#viewpdf?dispub=10274948
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Bentz, Brian Z. “In Vivo Optical Imaging for Targeted Drug Kinetics and Localization for Oral Surgery and Super-Resolution, Facilitated by Printed Phantoms.” 2017. Thesis, Purdue University. Accessed January 19, 2021.
http://pqdtopen.proquest.com/#viewpdf?dispub=10274948.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Bentz, Brian Z. “In Vivo Optical Imaging for Targeted Drug Kinetics and Localization for Oral Surgery and Super-Resolution, Facilitated by Printed Phantoms.” 2017. Web. 19 Jan 2021.
Vancouver:
Bentz BZ. In Vivo Optical Imaging for Targeted Drug Kinetics and Localization for Oral Surgery and Super-Resolution, Facilitated by Printed Phantoms. [Internet] [Thesis]. Purdue University; 2017. [cited 2021 Jan 19].
Available from: http://pqdtopen.proquest.com/#viewpdf?dispub=10274948.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Bentz BZ. In Vivo Optical Imaging for Targeted Drug Kinetics and Localization for Oral Surgery and Super-Resolution, Facilitated by Printed Phantoms. [Thesis]. Purdue University; 2017. Available from: http://pqdtopen.proquest.com/#viewpdf?dispub=10274948
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
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