subject:(Magnetization Transfer imaging)

Boston University

1. Maier, Mihaela. Magnetization transfer effect on T1 relaxometry on 1.5T vs. 3T.

Degree: MS, Bioimaging, 2017, Boston University

► PURPOSE: To assess the variability of incidental magnetization transfer effect (MT) by the number of slices and the magnetic field strength. METHODS: Various magnetic resonance… (more)

Subjects/Keywords: Medical imaging; Relaxometry; Magnetization transfer

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APA (6^th Edition):

Maier, M. (2017). Magnetization transfer effect on T1 relaxometry on 1.5T vs. 3T. (Masters Thesis). Boston University. Retrieved from http://hdl.handle.net/2144/26732

Chicago Manual of Style (16^th Edition):

Maier, Mihaela. “Magnetization transfer effect on T1 relaxometry on 1.5T vs. 3T.” 2017. Masters Thesis, Boston University. Accessed March 03, 2021. http://hdl.handle.net/2144/26732.

MLA Handbook (7^th Edition):

Maier, Mihaela. “Magnetization transfer effect on T1 relaxometry on 1.5T vs. 3T.” 2017. Web. 03 Mar 2021.

Vancouver:

Maier M. Magnetization transfer effect on T1 relaxometry on 1.5T vs. 3T. [Internet] [Masters thesis]. Boston University; 2017. [cited 2021 Mar 03]. Available from: http://hdl.handle.net/2144/26732.

Council of Science Editors:

Maier M. Magnetization transfer effect on T1 relaxometry on 1.5T vs. 3T. [Masters Thesis]. Boston University; 2017. Available from: http://hdl.handle.net/2144/26732

Delft University of Technology

2. Vedula, Mano (author). Myelin Imaging in Brain using Inhomogeneous Magnetization Transfer(ihMT) at 3T and 7T.

Degree: 2020, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:ed118642-7370-471f-9045-948f656887e3

►

Demyelination is described as loss of myelin sheath in neurons which could lead to disruption in signal transmission in nervous system. Inhomogeneous Magnetization Transfer(ihMT) is… (more)

Subjects/Keywords: Myelin imaging; MRI; Inhomogeneous Magnetization Transfer

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APA (6^th Edition):

Vedula, M. (. (2020). Myelin Imaging in Brain using Inhomogeneous Magnetization Transfer(ihMT) at 3T and 7T. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:ed118642-7370-471f-9045-948f656887e3

Chicago Manual of Style (16^th Edition):

Vedula, Mano (author). “Myelin Imaging in Brain using Inhomogeneous Magnetization Transfer(ihMT) at 3T and 7T.” 2020. Masters Thesis, Delft University of Technology. Accessed March 03, 2021. http://resolver.tudelft.nl/uuid:ed118642-7370-471f-9045-948f656887e3.

MLA Handbook (7^th Edition):

Vedula, Mano (author). “Myelin Imaging in Brain using Inhomogeneous Magnetization Transfer(ihMT) at 3T and 7T.” 2020. Web. 03 Mar 2021.

Vancouver:

Vedula M(. Myelin Imaging in Brain using Inhomogeneous Magnetization Transfer(ihMT) at 3T and 7T. [Internet] [Masters thesis]. Delft University of Technology; 2020. [cited 2021 Mar 03]. Available from: http://resolver.tudelft.nl/uuid:ed118642-7370-471f-9045-948f656887e3.

Council of Science Editors:

Vedula M(. Myelin Imaging in Brain using Inhomogeneous Magnetization Transfer(ihMT) at 3T and 7T. [Masters Thesis]. Delft University of Technology; 2020. Available from: http://resolver.tudelft.nl/uuid:ed118642-7370-471f-9045-948f656887e3

Louisiana State University

3. Schurr, Ryan Nicholas. Z-Spectral Modeling for Magnetization Transfer Ratio Asymmetry Calculations in Chemical Exchange Saturation Transfer MRI at 3 Tesla.

Degree: MS, Physical Sciences and Mathematics, 2015, Louisiana State University

URL: etd-06182015-155915 ; https://digitalcommons.lsu.edu/gradschool_theses/2661

► Chemical exchange saturation transfer (CEST) and magnetization transfer (MT) are types of magnetic resonance imaging (MRI) experiments in which contrast is based on the transfer… (more)

▼ Chemical exchange saturation transfer (CEST) and magnetization transfer (MT) are types of magnetic resonance imaging (MRI) experiments in which contrast is based on the transfer of magnetization from selectively saturated solute or macromolecular protons to bulk water protons. These processes offer insight into the chemical composition of tissue and are quantified by the asymmetry of the magnetization transfer ratio (MTRasym). This study was to develop a Z-spectral curve fitting procedure based on the underlying physics of CEST-MRI from which MTRasym values can be calculated and applied to distinguish healthy tissue from cancer. Z-spectra were collected from CEST-MR images of a phantom. The data were fit to both the proposed model which separately fits the upfield and downfield regions of the Z-spectra, and two polynomial models from literature. A preferred model was identified using the small sample bias-corrected Akaike’s Information Criterion (AICc). Z-spectra were collected from CEST-MR images of prostate cancer patients and fit with the same models; the preferred model was selected using the AICc. CEST-MR images of bladder cancer patients were acquired and the Z-spectra were fit with the preferred model identified from the phantom images. MTRasym was calculated at frequency offsets of 3.5 ppm and 2.0 ppm to determine if these quantities were capable of distinguishing normal bladder wall (NBW) from bladder cancer. The proposed fitting model with a 5th order polynomial for the downfield region was the preferred curve fitting model by the AICc model selection procedure for the phantom while a 6th order polynomial was preferred for the prostate cancer Z-spectra. MTRasym(2.0 ppm) values calculated from the bladder cancer Z-spectra did not differ significantly between the NBW and tumor regions. A statistically significant difference existed between the NBW and tumor regions for the MTRasym(3.5 ppm) values (p < 0.001). The proposed model was preferred to the polynomial models from literature based on the AICc metric. Application of the technique to patient images showed the potential to distinguish NBW from bladder cancer based on the statistically significant MTRasym(3.5 ppm) values in these regions.

Subjects/Keywords: MRI; CEST; magnetization transfer; quantitative imaging

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APA (6^th Edition):

Schurr, R. N. (2015). Z-Spectral Modeling for Magnetization Transfer Ratio Asymmetry Calculations in Chemical Exchange Saturation Transfer MRI at 3 Tesla. (Masters Thesis). Louisiana State University. Retrieved from etd-06182015-155915 ; https://digitalcommons.lsu.edu/gradschool_theses/2661

Chicago Manual of Style (16^th Edition):

Schurr, Ryan Nicholas. “Z-Spectral Modeling for Magnetization Transfer Ratio Asymmetry Calculations in Chemical Exchange Saturation Transfer MRI at 3 Tesla.” 2015. Masters Thesis, Louisiana State University. Accessed March 03, 2021. etd-06182015-155915 ; https://digitalcommons.lsu.edu/gradschool_theses/2661.

MLA Handbook (7^th Edition):

Schurr, Ryan Nicholas. “Z-Spectral Modeling for Magnetization Transfer Ratio Asymmetry Calculations in Chemical Exchange Saturation Transfer MRI at 3 Tesla.” 2015. Web. 03 Mar 2021.

Vancouver:

Schurr RN. Z-Spectral Modeling for Magnetization Transfer Ratio Asymmetry Calculations in Chemical Exchange Saturation Transfer MRI at 3 Tesla. [Internet] [Masters thesis]. Louisiana State University; 2015. [cited 2021 Mar 03]. Available from: etd-06182015-155915 ; https://digitalcommons.lsu.edu/gradschool_theses/2661.

Council of Science Editors:

Schurr RN. Z-Spectral Modeling for Magnetization Transfer Ratio Asymmetry Calculations in Chemical Exchange Saturation Transfer MRI at 3 Tesla. [Masters Thesis]. Louisiana State University; 2015. Available from: etd-06182015-155915 ; https://digitalcommons.lsu.edu/gradschool_theses/2661

Vanderbilt University

4. Harrigan, Robert Louis. Optic Nerve Characterization using Magnetic Resonance Imaging: The Search for Biomarkers.

Degree: PhD, Electrical Engineering, 2017, Vanderbilt University

URL: http://hdl.handle.net/1803/10773

► The optic nerve is a vital bundle of axons which carries all visual information from the retina posterior to the brain for higher order processing.… (more)

Subjects/Keywords: multi atlas segmentation; Optic nerve; conjugate gradient descent; magnetic resonance imaging; quantitative magnetization transfer

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APA (6^th Edition):

Harrigan, R. L. (2017). Optic Nerve Characterization using Magnetic Resonance Imaging: The Search for Biomarkers. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/10773

Chicago Manual of Style (16^th Edition):

Harrigan, Robert Louis. “Optic Nerve Characterization using Magnetic Resonance Imaging: The Search for Biomarkers.” 2017. Doctoral Dissertation, Vanderbilt University. Accessed March 03, 2021. http://hdl.handle.net/1803/10773.

MLA Handbook (7^th Edition):

Harrigan, Robert Louis. “Optic Nerve Characterization using Magnetic Resonance Imaging: The Search for Biomarkers.” 2017. Web. 03 Mar 2021.

Vancouver:

Harrigan RL. Optic Nerve Characterization using Magnetic Resonance Imaging: The Search for Biomarkers. [Internet] [Doctoral dissertation]. Vanderbilt University; 2017. [cited 2021 Mar 03]. Available from: http://hdl.handle.net/1803/10773.

Council of Science Editors:

Harrigan RL. Optic Nerve Characterization using Magnetic Resonance Imaging: The Search for Biomarkers. [Doctoral Dissertation]. Vanderbilt University; 2017. Available from: http://hdl.handle.net/1803/10773

The Ohio State University

5. Clark, Daniel James. Chemical Exchange Saturation Transfer and Quantitative MRI Methods: Applications for Osteoarthritis and Cartilage Injury.

Degree: PhD, Biomedical Engineering, 2015, The Ohio State University

URL: http://rave.ohiolink.edu/etdc/view?acc_num=osu1431016691

► Osteoarthritis (OA) is a huge disease burden in United States, affecting almost 30 million Americans, and is the leading cause of disability in the elderly.… (more)

▼ Osteoarthritis (OA) is a huge disease burden in United States, affecting almost 30 million Americans, and is the leading cause of disability in the elderly. Knee and hip replacements cost over $40 billion annually, but may be avoided through early detection of at risk cartilage and early intervention. There are abundant MRI tools for non-invasive, quantitative imaging that reveal characteristics of cartilage structure and physiology such as collagen alignment, molecular content, and health of subchondral bone vasculature. However, no quantitative MRI technique has been added to clinical standard of care for cartilage imaging because of lack of specificity and technical difficulty. Chemical exchange saturation transfer (CEST) MRI is a promising technique to detect small metabolites such as glutamate, creatine and glucose, as well as large soluble molecules such as protein, proteoglycans, and glycogen. It has been demonstrated that CEST MRI can detect glycosaminoglycan (GAG), a proteoglycan crucial to the functioning of healthy articular cartilage, however only with high-field non-clinical scanners (> 3 Tesla). In osteoarthritis development, reduction in GAG content is a preliminary step before gross changes in cartilage thickness and joint space, and therefore clinical methods to detect GAG may have a tremendous impact on OA prevention. In this dissertation, we discuss multiple quantitative MRI techniques used to characterize articular cartilage, but then focus on CEST MRI. A miniature horse model of cartilage injury is used to evaluate several MRI techniques through serial imaging of the healing process over the course of one year. While promising, the techniques lack specificity and are technically challenging to perform, especially delayed gadolinium enchance MRI of cartilage (dGEMRIC), a technique used to detect GAG content. To meet the challenge of GAG detection at 3 Tesla, we hypothesized that a variant of CEST, using a novel variable saturation power (vCEST) scheme could detect the hydroxyl protons of the GAG molecule. We show through phantom studies that vCEST robustly detects glycogen and glucose (hydroxyl rich molecules) in multiple environments (aqueous, multiple solutes, and within semi-solid tissue), an improvement over typical CEST MRI. We offer in vivo imaging that shows contrast between lesions and normal cartilage using vCEST that is not apparent in typical CEST imaging. Finally, we propose an extension of vCEST that combines it with quantitative magnetization transfer (qMT). We use in vivo imaging of a healthy brain to show that vCEST/qMT can produce hydroxyl, amine/amide, and NOE maps that are consistent with results achieved at higher field-strengths. Since GAG molecules, in addition to hydroxyl moieties, also have an amine proton in each disaccharide unit, we hypothesize that the vCEST/qMT combine technique might further specify GAG detection at 3 T, which will be included in future work.The theme of this work is cartilage imaging, but it focuses on developing a novel technology for molecular… Advisors/Committee Members: Knopp, Michael (Advisor).

Subjects/Keywords: Biomedical Engineering; Medical Imaging; chemical exchange; CEST; magnetization transfer; MRI; cartilage; glycosaminoglycan

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APA (6^th Edition):

Clark, D. J. (2015). Chemical Exchange Saturation Transfer and Quantitative MRI Methods: Applications for Osteoarthritis and Cartilage Injury. (Doctoral Dissertation). The Ohio State University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=osu1431016691

Chicago Manual of Style (16^th Edition):

Clark, Daniel James. “Chemical Exchange Saturation Transfer and Quantitative MRI Methods: Applications for Osteoarthritis and Cartilage Injury.” 2015. Doctoral Dissertation, The Ohio State University. Accessed March 03, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=osu1431016691.

MLA Handbook (7^th Edition):

Clark, Daniel James. “Chemical Exchange Saturation Transfer and Quantitative MRI Methods: Applications for Osteoarthritis and Cartilage Injury.” 2015. Web. 03 Mar 2021.

Vancouver:

Clark DJ. Chemical Exchange Saturation Transfer and Quantitative MRI Methods: Applications for Osteoarthritis and Cartilage Injury. [Internet] [Doctoral dissertation]. The Ohio State University; 2015. [cited 2021 Mar 03]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1431016691.

Council of Science Editors:

Clark DJ. Chemical Exchange Saturation Transfer and Quantitative MRI Methods: Applications for Osteoarthritis and Cartilage Injury. [Doctoral Dissertation]. The Ohio State University; 2015. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1431016691

University of Western Ontario

6. Booth, William J. Reductions in Muscle Quantity and Quality in Old and Very Old Men: New Insights into the Progression of Sarcopenia.

Degree: 2012, University of Western Ontario

URL: https://ir.lib.uwo.ca/etd/511

► Healthy adult aging is associated with sarcopenia; a loss of skeletal muscle mass known as. Major contributors to this process include functional and morphological changes… (more)

▼ Healthy adult aging is associated with sarcopenia; a loss of skeletal muscle mass known as. Major contributors to this process include functional and morphological changes in the contractile tissue and within the neuromuscular system. Currently, the relationship between muscle mass, normalized strength, structural integrity, and neuromuscular properties [such as motor unit number estimates (MUNE)], in the tibialis anterior (TA) with aging is largely unknown. Therefore, to examine this relationship we recruited twelve young (25 ± 3 years old), six old (68 ± 5 years old) and six very old (79 ± 3 years old) men. Magnetic resonance (MR) images were obtained from the entire musculature of the leg from the tibial plateau to the malleoli. Muscle cross-sectional areas (CSA) were calculated using image processing software. Strength was measured as maximal isometric voluntary dorsiflexion contraction (MVC) torque; this was then normalized to CSA. Structural integrity of the muscle was evaluated by magnetization transfer ratio (MTR) using magnetic resonance imaging (MRI). Neuromuscular measures were also collected and decomposition-enhanced spike-triggered averaging was used to collect surface and intramuscular electromyography (EMG) signals. From these data, estimates of motor unit numbers were made. Muscle CSA was less only in the very old (11.2cm2), no differences existed between the young (13.4cm2) and old (11.7cm2). Strength was ~26% lower in the old and ~24% in the very old than the young. When strength was normalized to CSA there were no differences between the groups. Very old men had ~8% lower MTR values than the young and old men, with no differences between young and old. Neuromuscular measures, specifically the combination of a decreased compound muscle action potential (CMAP) and increased surface motor unit potential (SMUP), resulted in a decrease in MUNE between young [~147 motor units (MU)] and old (~109 MUs) and also between young and very old (~80 MUs). In conclusion, muscular structure and function appear to be maintained in the older adult due to compensatory motor unit remodeling; however in the very old adult the structural integrity of the muscle becomes compromised as motor unit losses are greater resulting in the acceleration of sarcopenia.

Subjects/Keywords: aging; normalized strength; magnetic resonance imaging; magnetization transfer ratio; motor unit number estimates; neuromuscular; Other Medicine and Health Sciences

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APA (6^th Edition):

Booth, W. J. (2012). Reductions in Muscle Quantity and Quality in Old and Very Old Men: New Insights into the Progression of Sarcopenia. (Thesis). University of Western Ontario. Retrieved from https://ir.lib.uwo.ca/etd/511

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Booth, William J. “Reductions in Muscle Quantity and Quality in Old and Very Old Men: New Insights into the Progression of Sarcopenia.” 2012. Thesis, University of Western Ontario. Accessed March 03, 2021. https://ir.lib.uwo.ca/etd/511.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Booth, William J. “Reductions in Muscle Quantity and Quality in Old and Very Old Men: New Insights into the Progression of Sarcopenia.” 2012. Web. 03 Mar 2021.

Vancouver:

Booth WJ. Reductions in Muscle Quantity and Quality in Old and Very Old Men: New Insights into the Progression of Sarcopenia. [Internet] [Thesis]. University of Western Ontario; 2012. [cited 2021 Mar 03]. Available from: https://ir.lib.uwo.ca/etd/511.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Booth WJ. Reductions in Muscle Quantity and Quality in Old and Very Old Men: New Insights into the Progression of Sarcopenia. [Thesis]. University of Western Ontario; 2012. Available from: https://ir.lib.uwo.ca/etd/511

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Duke University

7. Avram, Alexandru Vlad. Diffusion Tensor Imaging of Myelin Water .

Degree: 2011, Duke University

URL: http://hdl.handle.net/10161/5700

► In recent years, the emergence of diffusion tensor imaging (DTI) has provided a unique means via water diffusional characteristics to investigate the white matter… (more)

▼ In recent years, the emergence of diffusion tensor imaging (DTI) has provided a unique means via water diffusional characteristics to investigate the white matter integrity in the human brain, and its impact on neuronal functions. However, since the characterization of white matter integrity using DTI often lacks tissue specificity, most research studies report changes in anisotropy that are not explicitly correlated with particular cellular origins. To improve the utility of DTI in translational neuroimaging, it is critical to develop DTI acquisition techniques that are quantitative and tissue specific. There are, nevertheless, existing methods for tissue specificity. For example, myelin water images can be generated using multiple echo time (TE) or magnetization transfer techniques. These techniques can detect changes in the concentration of myelin associated markers, but not in their spatial organization. Most white matter pathologies however start with early microstructural changes in the myelin sheaths during which the tissue contents remain similar and are thus not differentiable on a conventional MR image. Thus, the ability to construct a diffusion tensor that is myelin specific can have an immediate impact on our better understanding myelin physiology and pathophysiology during brain development. Unfortunately, the myelin water signal decays rapidly because of its short transverse relaxation time constant (T2 < 50 ms), especially in DTI experiments where the echo time (TE) can be as large as 100ms. Even in special cases where the TE is shorter, the lack of myelin selectivity in conventional DTI techniques makes assessment of myelin microstructure extremely challenging. Thus we need to develop a DTI methodology that will greatly shorten the TE and allow myelin selectivity. To address these challenges we have developed innovative DTI acquisition methodologies that can specifically assess myelin microstructural changes in white matter. To preserve more signal from myelin water we used a stimulated echo DTI implementation. In our initial approach we integrated this sequence with a magnetization transfer preparation to achieve additional differentiating sensitization to myelin water and derive a myelin water weighted (MWW) diffusion tensor. Our results indicate that, compared to the conventional DTI, myelin water diffuses along the axis of the fiber, but has the same has larger fractional anisotropy (FA) due to significantly smaller radial diffusivity. The limited specificity of MT and high radio frequency power deposition of MT-DTI restrict its applicability in clinical studies. To obtain increased myelin specificity we implemented a robust stimulated echo DTI sequence with segmented spiral-out readout trajectory for achieving minimal TE on clinical MRI scanners. To ensure high spatial accuracy throughout the DTI scan we further develop a methodology for inherently and dynamically correcting both motion induced phase errors and off-resonance effects due to magnetic field… Advisors/Committee Members: Song, Allen W (advisor).

Subjects/Keywords: Biomedical Engineering; Medical Imaging and Radiology; Neurosciences; diffusion tensor imaging; magnetization transfer; multi-TE imaging; myelin microstructure; myelin water; white matter disease

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APA (6^th Edition):

Avram, A. V. (2011). Diffusion Tensor Imaging of Myelin Water . (Thesis). Duke University. Retrieved from http://hdl.handle.net/10161/5700

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Avram, Alexandru Vlad. “Diffusion Tensor Imaging of Myelin Water .” 2011. Thesis, Duke University. Accessed March 03, 2021. http://hdl.handle.net/10161/5700.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Avram, Alexandru Vlad. “Diffusion Tensor Imaging of Myelin Water .” 2011. Web. 03 Mar 2021.

Vancouver:

Avram AV. Diffusion Tensor Imaging of Myelin Water . [Internet] [Thesis]. Duke University; 2011. [cited 2021 Mar 03]. Available from: http://hdl.handle.net/10161/5700.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Avram AV. Diffusion Tensor Imaging of Myelin Water . [Thesis]. Duke University; 2011. Available from: http://hdl.handle.net/10161/5700

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Vanderbilt University

8. Ou, Xiawei. Quantitative magnetization transfer imaging techniques and applications.

Degree: PhD, Physics, 2007, Vanderbilt University

URL: http://hdl.handle.net/1803/14808

► This dissertation discusses magnetization transfer effects in magnetic resonance imaging and the development and applications of quantitative magnetization transfer imaging techniques. Specifically, the magnetization transfer… (more)

Subjects/Keywords: diffusion tensor imaging; quantitative magnetization transfer; magnetic resonance imaging; myelin; central nervous system

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APA (6^th Edition):

Ou, X. (2007). Quantitative magnetization transfer imaging techniques and applications. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/14808

Chicago Manual of Style (16^th Edition):

Ou, Xiawei. “Quantitative magnetization transfer imaging techniques and applications.” 2007. Doctoral Dissertation, Vanderbilt University. Accessed March 03, 2021. http://hdl.handle.net/1803/14808.

MLA Handbook (7^th Edition):

Ou, Xiawei. “Quantitative magnetization transfer imaging techniques and applications.” 2007. Web. 03 Mar 2021.

Vancouver:

Ou X. Quantitative magnetization transfer imaging techniques and applications. [Internet] [Doctoral dissertation]. Vanderbilt University; 2007. [cited 2021 Mar 03]. Available from: http://hdl.handle.net/1803/14808.

Council of Science Editors:

Ou X. Quantitative magnetization transfer imaging techniques and applications. [Doctoral Dissertation]. Vanderbilt University; 2007. Available from: http://hdl.handle.net/1803/14808

Vanderbilt University

9. Dula, Adrienne Nicole. Micro-anatomical characterization of central white matter using magnetic resonance imaging.

Degree: PhD, Biomedical Engineering, 2008, Vanderbilt University

URL: http://hdl.handle.net/1803/12177

► Most magnetic resonance imaging techniques offer tissue contrast but provide limited information regarding the variation of the magnetic resonance signal that exists on a smaller… (more)

Subjects/Keywords: quantitative magnetization transfer; multiexponential T2; Spinal cord – Magnetic resonance imaging; myelin; Myelination

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APA (6^th Edition):

Dula, A. N. (2008). Micro-anatomical characterization of central white matter using magnetic resonance imaging. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/12177

Chicago Manual of Style (16^th Edition):

Dula, Adrienne Nicole. “Micro-anatomical characterization of central white matter using magnetic resonance imaging.” 2008. Doctoral Dissertation, Vanderbilt University. Accessed March 03, 2021. http://hdl.handle.net/1803/12177.

MLA Handbook (7^th Edition):

Dula, Adrienne Nicole. “Micro-anatomical characterization of central white matter using magnetic resonance imaging.” 2008. Web. 03 Mar 2021.

Vancouver:

Dula AN. Micro-anatomical characterization of central white matter using magnetic resonance imaging. [Internet] [Doctoral dissertation]. Vanderbilt University; 2008. [cited 2021 Mar 03]. Available from: http://hdl.handle.net/1803/12177.

Council of Science Editors:

Dula AN. Micro-anatomical characterization of central white matter using magnetic resonance imaging. [Doctoral Dissertation]. Vanderbilt University; 2008. Available from: http://hdl.handle.net/1803/12177

10. Prevost, Valentin. Validation du transfert d'aimantation inhomogène (ihMT) comme nouveau biomarqueur IRM de la myéline : Validation of inhomogeneous magnetization transfer (ihMT) as a new MRI myelin biomarker.

Degree: Docteur es, Neurosciences, 2018, Aix Marseille Université

URL: http://www.theses.fr/2018AIXM0037

►

L’imagerie par résonance magnétique (IRM) est une technique d’imagerie médicale largement utilisée pour son caractère non-invasif et pour sa capacité à explorer les tissus mous.… (more)

▼

L’imagerie par résonance magnétique (IRM) est une technique d’imagerie médicale largement utilisée pour son caractère non-invasif et pour sa capacité à explorer les tissus mous. Des techniques IRM avancées et innovantes ont été développées de manière à améliorer la spécificité du signal des techniques conventionnelles et ainsi accéder à de nouvelles informations. Un axe de recherche particulièrement important en IRM concerne la possibilité d’accéder in vivo à des informations sur la myéline. Cette dernière est un constituant majeur du système nerveux central qui assure la bonne conduction nerveuse. Sa dégradation est l’une des caractéristiques de la sclérose en plaques, qui est la première cause de handicap sévère non traumatique chez le jeune adulte. Imager la myéline par IRM demeure néanmoins un challenge du fait du temps de relaxation T2 très court des protons la constituant. Le transfert d’aimantation inhomogène (ihMT) est une technique récemment découverte qui permet d’isoler le signal de composantes macromoléculaires grâce à leurs propriétés de relaxation dipolaire, caractérisées par la constante T1D. L’objectif de ce travail de thèse a concerné la validation de la technique ihMT comme biomarqueur de la myéline et l’évaluation de la spécificité du signal pour la myéline, sur des modèles murins (souris).

Magnetic resonance imaging (MRI) is a non-invasive medical imaging technique, widely used to explore soft tissues. Advanced and innovated MRI techniques have been developed to improve the specificity of conventional MR sequences thus allowing accessing new information. A particularly important research topic concerns the ability to in vivo access myelin information. Myelin is a major component of the central nervous system responsible for a good nerve conduction. Myelin alteration occurs in multiple sclerosis, one of the main cause for young adult permanent disability. However, myelin MRI is challenged by the very short relaxation time, T2, of myelin protons. Inhomogeneous magnetization transfer (ihMT) is a recent technique, which allows assessing macromolecular tissue component by exploiting their dipolar order relaxation properties, characterized by the time constant T1D. The objective of this thesis concerned the validation of ihMT as a myelin biomarker and the evaluation of the specificity of ihMT for myelin on mouse models.

Advisors/Committee Members: Duhamel, Guillaume (thesis director), Alsop, David (thesis director).

Subjects/Keywords: Imagerie; Irm; Myéline; IhMT; Transfert d'aimantation; Inhomogène; Modèle; Cuprizone; Validation; Biomarqueur; Imaging; Mri; Myelin; IhMT; Magnetization transfer; Inhomogeneous; Model; Cuprizone; Validation; Biomarker

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APA (6^th Edition):

Prevost, V. (2018). Validation du transfert d'aimantation inhomogène (ihMT) comme nouveau biomarqueur IRM de la myéline : Validation of inhomogeneous magnetization transfer (ihMT) as a new MRI myelin biomarker. (Doctoral Dissertation). Aix Marseille Université. Retrieved from http://www.theses.fr/2018AIXM0037

Chicago Manual of Style (16^th Edition):

Prevost, Valentin. “Validation du transfert d'aimantation inhomogène (ihMT) comme nouveau biomarqueur IRM de la myéline : Validation of inhomogeneous magnetization transfer (ihMT) as a new MRI myelin biomarker.” 2018. Doctoral Dissertation, Aix Marseille Université. Accessed March 03, 2021. http://www.theses.fr/2018AIXM0037.

MLA Handbook (7^th Edition):

Prevost, Valentin. “Validation du transfert d'aimantation inhomogène (ihMT) comme nouveau biomarqueur IRM de la myéline : Validation of inhomogeneous magnetization transfer (ihMT) as a new MRI myelin biomarker.” 2018. Web. 03 Mar 2021.

Vancouver:

Prevost V. Validation du transfert d'aimantation inhomogène (ihMT) comme nouveau biomarqueur IRM de la myéline : Validation of inhomogeneous magnetization transfer (ihMT) as a new MRI myelin biomarker. [Internet] [Doctoral dissertation]. Aix Marseille Université 2018. [cited 2021 Mar 03]. Available from: http://www.theses.fr/2018AIXM0037.

Council of Science Editors:

Prevost V. Validation du transfert d'aimantation inhomogène (ihMT) comme nouveau biomarqueur IRM de la myéline : Validation of inhomogeneous magnetization transfer (ihMT) as a new MRI myelin biomarker. [Doctoral Dissertation]. Aix Marseille Université 2018. Available from: http://www.theses.fr/2018AIXM0037

11. Oh, Jiwon. QUANTITATIVE SPINAL CORD MRI IN MULTIPLE SCLEROSIS.

Degree: 2014, Johns Hopkins University

URL: http://jhir.library.jhu.edu/handle/1774.2/36960

► Background: The spinal cord (SC) is a compact structure with a functional anatomic organization that makes it an ideal substrate to study structure-function relationships in… (more)

▼ Background: The spinal cord (SC) is a compact structure with a functional anatomic organization that makes it an ideal substrate to study structure-function relationships in multiple sclerosis (MS). Despite these benefits, the SC has been challenging to study using conventional MRI measures due to limited clinical-radiological correlations and technical difficulties. Quantitative MRI techniques in the SC, including diffusion tensor imaging (DTI) and magnetization-transfer imaging have demonstrated increased sensitivity to underlying tissue microstructural properties in comparison to conventional MRI techniques, and have the potential to provide new insights into the extent and type of tissue damage mediating clinical disability in MS tissue. Methods: 133 MS patients underwent 3-tesla cervical SC-MRI, clinical assessment, and optical coherence tomography on an annual basis over a median duration of 726 days. Quantitative SC-MRI indices, including SC-cross-sectional area (CSA), fractional anisotropy (FA), mean diffusivity (MD), perpendicular diffusivity (λ⊥), parallel diffusivity (λ||), and magnetization-transfer ratio (MTR) were calculated across segments C3-C4. Cross-sectional relationships between clinical disability, SC-MRI indices, and retinal layers were assessed. Longitudinal change in MRI-indices over the follow-up period, and its relationship to clinical disability were assessed. The impact of SC volume normalization by subject height, SC length, and intracranial volume on the ability to detect group differences and clinical-radiological correlations were assessed. Results: Quantitative SC-MRI indices demonstrate independent associations with system-specific and global clinical dysfunction beyond what can be detected by conventional MRI. Significant correlations exist between SC-MRI and retinal layers, and both exhibit independent relationships with clinical dysfunction. There are measurable longitudinal changes in SC-MRI indices, and subject-specific trajectories of SC-MRI index change are relevant to disability at follow-up. SC normalization by SC length was consistently the best strategy to accentuate group differences and to strengthen clinical-radiological correlations. Interpretation: Quantitative SC-MRI measures provide clinically relevant information in MS patients beyond that which can be gleaned from conventional, lesion-based measurements alone. Longitudinal changes in SC MRI-measures are detectable over 2 years, and subject-specific trajectories of SC-MRI index change are relevant to disability progression, warranting further investigation. Further development of quantitative SC-MRI techniques will expand their practical utility in the clinical setting. Advisors/Committee Members: Diener-West, Marie (advisor).

Subjects/Keywords: multiple sclerosis; magnetic resonance imaging; spinal cord; diffusion tensor imaging; magnetization transfer imaging

…approach that holds promise in MS is magnetization transfer imaging (MTI).5 MTI is a… …diffusion-tensor imaging (DTI) and magnetization-transfer imaging (MTI) to… …technique based on the transfer of magnetization from restricted water molecules in macromolecular… …tissues such as myelin to unrestricted free water. The degree of magnetization transfer… …measured as the magnetization transfer ratio (MTR), is sensitive to myelin content…

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APA (6^th Edition):

Oh, J. (2014). QUANTITATIVE SPINAL CORD MRI IN MULTIPLE SCLEROSIS. (Thesis). Johns Hopkins University. Retrieved from http://jhir.library.jhu.edu/handle/1774.2/36960

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Oh, Jiwon. “QUANTITATIVE SPINAL CORD MRI IN MULTIPLE SCLEROSIS.” 2014. Thesis, Johns Hopkins University. Accessed March 03, 2021. http://jhir.library.jhu.edu/handle/1774.2/36960.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Oh, Jiwon. “QUANTITATIVE SPINAL CORD MRI IN MULTIPLE SCLEROSIS.” 2014. Web. 03 Mar 2021.

Vancouver:

Oh J. QUANTITATIVE SPINAL CORD MRI IN MULTIPLE SCLEROSIS. [Internet] [Thesis]. Johns Hopkins University; 2014. [cited 2021 Mar 03]. Available from: http://jhir.library.jhu.edu/handle/1774.2/36960.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Oh J. QUANTITATIVE SPINAL CORD MRI IN MULTIPLE SCLEROSIS. [Thesis]. Johns Hopkins University; 2014. Available from: http://jhir.library.jhu.edu/handle/1774.2/36960

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

12. Rasoanandrianina, Rivo. Toward the characterization of micro- and macro- traumatisms of the human cervical spinal cord in rugby : a multimodal approach combining magnetic resonance imaging and biomechanical finite element modelling : Vers la caractérisation des micros et macro-traumatismes de la moelle épinière cervicale dans la pratique du rugby : une approche multimodale combinant imagerie par résonnance magnétique et modélisation biomécanique par éléments finis.

Degree: Docteur es, Biomécanique, 2019, Aix Marseille Université

URL: http://www.theses.fr/2019AIXM0035

►

Dans la pratique du rugby à XV, l’intégrité de la moelle épinière (ME) est menacée par les rares macro-traumatismes du rachis cervical, et par les… (more)

▼

Dans la pratique du rugby à XV, l’intégrité de la moelle épinière (ME) est menacée par les rares macro-traumatismes du rachis cervical, et par les chargements répétitifs entrainant l’apparition de pathologies dégénératives. Comment quantifier ces altérations, quels sont les mécanismes qui les président ?Pour aborder ces questions, la faisabilité et l’intérêt d’un protocole IRM multiparamétrique en contexte dégénératif ont tout d’abord été investigués. Puis, une récente technique de relaxométrie T1 3D et une acquisition ihMT multi-coupes à multiples orientations permettant d’évaluer le contenu macromoléculaire des tissus, en particulier la myéline, ont été développées pour évaluer le caractère diffus des altérations. Préliminairement appliqué sur quelques joueurs, ce protocole a ainsi démontré la faisabilité d’une exploration approfondie par IRM multiparamétrique de la ME cervicale dans le rugby.En complément de cela, une étude préliminaire utilisant un modèle éléments finis (MEF) détaillé a été menée pour évaluer la réponse mécanique des sous-régions de la ME soumises à des chargements mécaniques primaires. Par la suite, une étude préliminaire des risques neurologiques liés à un canal vertébral étroit (observé chez certains joueurs) a été conduite en modifiant la géométrie du MEF. A l’interface entre l’IRM et la biomécanique, ces travaux préliminaires ont posé les premiers jalons pour une caractérisation fine et robuste des altérations tissulaires au niveau médullaire dans le rugby. A terme, cette approche permettrait de proposer de nouveaux éléments pour une éventuelle amélioration du bilan d’aptitude des joueurs et de proposer des programmes préventifs améliorés.

In Rugby Union practice, the cervical spinal cord (CSC) could be involved in rare cervical spine (CS) traumatic injuries and also be threatened by the neck exposure to repetitive impacts assumed to induce early degenerative tissue alterations. How to quantify these impairments? What are the underlying pathophysiological mechanisms? To answer these questions, efforts were first directed towards the investigative potential of an advanced multiparametric Magnetic Resonance Imaging (MRI) protocol in degenerative contexts. Then, a new MRI protocol covering the whole CSC, including a recent 3D T1 relaxometry technique and a multi-slice multi-angle ihMT acquisition evaluating tissue myelin-content, was optimized. Preliminarily-applied to few players, this new optimized protocol showed the feasibility of a fine and diffuse CSC characterization in rugby. In parallel and as a complement, preliminary finite element modelling (FEM) analyses were also conducted to evaluate the mechanical responses of CSC sub-regions under primary loading mechanisms. Then, the same loading mechanisms were applied to a geometrically-modified FEM reproducing a narrow vertebral canal, reported to occur in some players therefore allowing to evaluate the effect of rugby-related CS degenerative changes on the CSC mechanical response under traumatic loadings. These preliminary,…

Advisors/Committee Members: Arnoux, Pierre-Jean (thesis director), Callot, Virginie (thesis director).

Subjects/Keywords: Moelle épinière; Rugby; Micro-Traumatismes; Macro-Traumatismes; Imagerie par Résonance Magnétique; Modélisation par éléments finis; Simulation numérique; Imagerie du tenseur de diffusion; Imagerie du transfert d'aimantation; Relaxométrie; Spinal cord; Rugby; Micro-Traumatisms; Macro-Traumatisms; Magnetic Resonance Imaging; Finite element modelling; Numerical simulation; Diffusion Tensor Imaging; Magnetization Transfer imaging; Relaxometry; 612

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Rasoanandrianina, R. (2019). Toward the characterization of micro- and macro- traumatisms of the human cervical spinal cord in rugby : a multimodal approach combining magnetic resonance imaging and biomechanical finite element modelling : Vers la caractérisation des micros et macro-traumatismes de la moelle épinière cervicale dans la pratique du rugby : une approche multimodale combinant imagerie par résonnance magnétique et modélisation biomécanique par éléments finis. (Doctoral Dissertation). Aix Marseille Université. Retrieved from http://www.theses.fr/2019AIXM0035

Chicago Manual of Style (16^th Edition):

Rasoanandrianina, Rivo. “Toward the characterization of micro- and macro- traumatisms of the human cervical spinal cord in rugby : a multimodal approach combining magnetic resonance imaging and biomechanical finite element modelling : Vers la caractérisation des micros et macro-traumatismes de la moelle épinière cervicale dans la pratique du rugby : une approche multimodale combinant imagerie par résonnance magnétique et modélisation biomécanique par éléments finis.” 2019. Doctoral Dissertation, Aix Marseille Université. Accessed March 03, 2021. http://www.theses.fr/2019AIXM0035.

MLA Handbook (7^th Edition):

Rasoanandrianina, Rivo. “Toward the characterization of micro- and macro- traumatisms of the human cervical spinal cord in rugby : a multimodal approach combining magnetic resonance imaging and biomechanical finite element modelling : Vers la caractérisation des micros et macro-traumatismes de la moelle épinière cervicale dans la pratique du rugby : une approche multimodale combinant imagerie par résonnance magnétique et modélisation biomécanique par éléments finis.” 2019. Web. 03 Mar 2021.

Vancouver:

Rasoanandrianina R. Toward the characterization of micro- and macro- traumatisms of the human cervical spinal cord in rugby : a multimodal approach combining magnetic resonance imaging and biomechanical finite element modelling : Vers la caractérisation des micros et macro-traumatismes de la moelle épinière cervicale dans la pratique du rugby : une approche multimodale combinant imagerie par résonnance magnétique et modélisation biomécanique par éléments finis. [Internet] [Doctoral dissertation]. Aix Marseille Université 2019. [cited 2021 Mar 03]. Available from: http://www.theses.fr/2019AIXM0035.

Council of Science Editors:

Rasoanandrianina R. Toward the characterization of micro- and macro- traumatisms of the human cervical spinal cord in rugby : a multimodal approach combining magnetic resonance imaging and biomechanical finite element modelling : Vers la caractérisation des micros et macro-traumatismes de la moelle épinière cervicale dans la pratique du rugby : une approche multimodale combinant imagerie par résonnance magnétique et modélisation biomécanique par éléments finis. [Doctoral Dissertation]. Aix Marseille Université 2019. Available from: http://www.theses.fr/2019AIXM0035

13. Santos, José Eduardo Peixoto. Estudo das relações entre populações celulares, expressão de aquaporina-4 e sulfato de condroitina com o tempo de relaxamento e a taxa de transferência de magnetização no hipocampo de pacientes com epilepsia do lobo temporal farmacorresistente.

Degree: PhD, Neurologia, 2014, University of São Paulo

URL: http://www.teses.usp.br/teses/disponiveis/17/17140/tde-19122014-154406/ ;

► Racional: A epilepsia do lobo temporal está comumente associada à farmacorresistência e tem a esclerose hipocampal como achado neuropatológico em mais da metade dos casos.… (more)

▼ Racional: A epilepsia do lobo temporal está comumente associada à farmacorresistência e tem a esclerose hipocampal como achado neuropatológico em mais da metade dos casos. Histologicamente, a esclerose hipocampal está associada à perda neuronal diferencial e gliose, além de alterações nos níveis de moléculas associadas à homeostase da água tecidual, como a aquaporina 4 e a molécula de matriz sulfato de condroitina. Em imagens de ressonância nuclear magnética, a esclerose é caracterizada por redução de volume em sequências ponderadas em T1, aumento de sinal e tempo de relaxamento em sequências ponderadas em T2 e redução na transferência de magnetização. Justificativa e Objetivos: Uma vez que tanto o sinal T2 quando a transferência de magnetização são dependentes da água tecidual, nosso objetivo é avaliar, na formação hipocampal de pacientes com epilepsia do lobo temporal, as correlações entre populações celulares e moléculas ligadas à homeostase da água e as imagens ponderadas em T2 e transferência de magnetização. Visamos ainda definir, na formação hipocampal de indivíduos sem alterações neuropatológicas, o volume de cada um dos subcampos hipocampais. Metodologia: Pacientes com epilepsia do lobo temporal farmacorresistente (ELT, n = 43), bem como voluntários sadios (controle radiológico, CH, n = 20), foram submetidos a exames de ressonância magnética em máquina de 3T para mensuração da volumetria hipocampal, tempo de relaxamento T2 e transferência de magnetização hipocampal (exames in vivo). Após o tratamento cirúrgico para o controle das crises, os hipocampos dos pacientes com ELT foram fixados por 8 dias e submetidos aos exames ex vivo em máquina de 3T para cálculo do tempo de relaxamento T2 de cada subcampo hipocampal. Hipocampos controle (Controle historadiológico, CHR, n = 14), foram obtidos de autópsias de pacientes sem histórico ante-mortem de doença neurológica ou presença de patologia no exame do encéfalo pos mortem. Ambos os grupos controle foram pareados para idade em relação ao grupo ELT. Alguns dos casos CHR (n = 6) foram também submetidos à imagem 3D T2 em máquina de 4,7T para cálculo de volumetria dos subcampos hipocampais. Após emblocamento em parafina, secções coronais hipocampais dos casos CHR e ELT foram submetidas às técnicas de histoquímica básica Hematoxilina e Eosina e Luxol Fast Blue, e às imuno-histoquímicas para avaliação das populações neuronais (NeuN), astrócitos reativos (GFAP), micróglias ativadas (HLA-DR) e para a expressão de aquaporina 4 (AQP4) e níveis de sulfato de condroitina (CS-56). Para a comparação entre os grupos, foram realizados testes t para dados paramétricos e Mann-Whitney para dados não-paramétricos. Testes de correlação foram empregados para análise da associação entre as avaliações histológicas e os exames de ressonância magnética. Resultados: Pacientes com ELT apresentaram menor volume hipocampal, maior tempo de relaxamento T2 e menor transferência de magnetização no exame in vivo, quando comparados com o CR. O exame ex vivo para a volumetria dos subcampos… Advisors/Committee Members: Leite, João Pereira.

Subjects/Keywords: aquaporin 4; aquaporina 4; chondroitin sulfate; densidade neuronal; epilepsia do lobo temporal; extracellular matrix; gliose; gliosis; hipocampo; hippocampus; magnetic resonance imaging; magnetization transfer; matriz extracelular; neuron density; relaxometria; relaxometry; ressonância magnética; sulfato de condroitina; temporal lobe epilepsy; transferência de magnetização; volumetria; volumetry

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Santos, J. E. P. (2014). Estudo das relações entre populações celulares, expressão de aquaporina-4 e sulfato de condroitina com o tempo de relaxamento e a taxa de transferência de magnetização no hipocampo de pacientes com epilepsia do lobo temporal farmacorresistente. (Doctoral Dissertation). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/17/17140/tde-19122014-154406/ ;

Chicago Manual of Style (16^th Edition):

Santos, José Eduardo Peixoto. “Estudo das relações entre populações celulares, expressão de aquaporina-4 e sulfato de condroitina com o tempo de relaxamento e a taxa de transferência de magnetização no hipocampo de pacientes com epilepsia do lobo temporal farmacorresistente.” 2014. Doctoral Dissertation, University of São Paulo. Accessed March 03, 2021. http://www.teses.usp.br/teses/disponiveis/17/17140/tde-19122014-154406/ ;.

MLA Handbook (7^th Edition):

Santos, José Eduardo Peixoto. “Estudo das relações entre populações celulares, expressão de aquaporina-4 e sulfato de condroitina com o tempo de relaxamento e a taxa de transferência de magnetização no hipocampo de pacientes com epilepsia do lobo temporal farmacorresistente.” 2014. Web. 03 Mar 2021.

Vancouver:

Santos JEP. Estudo das relações entre populações celulares, expressão de aquaporina-4 e sulfato de condroitina com o tempo de relaxamento e a taxa de transferência de magnetização no hipocampo de pacientes com epilepsia do lobo temporal farmacorresistente. [Internet] [Doctoral dissertation]. University of São Paulo; 2014. [cited 2021 Mar 03]. Available from: http://www.teses.usp.br/teses/disponiveis/17/17140/tde-19122014-154406/ ;.

Council of Science Editors:

Santos JEP. Estudo das relações entre populações celulares, expressão de aquaporina-4 e sulfato de condroitina com o tempo de relaxamento e a taxa de transferência de magnetização no hipocampo de pacientes com epilepsia do lobo temporal farmacorresistente. [Doctoral Dissertation]. University of São Paulo; 2014. Available from: http://www.teses.usp.br/teses/disponiveis/17/17140/tde-19122014-154406/ ;

14. Jiang, Xu. QUANTITATIVE STUDY OF LONGITUDINAL RELAXATION (T₁) CONTRAST MECHANISMS IN BRAIN MRI.

Degree: Physics, 2017, University of Maryland

URL: http://hdl.handle.net/1903/19315

► Longitudinal relaxation (T₁) contrast in MRI is important for studying brain morphology and is widely used in clinical applications. Although MRI only detects signals from… (more)

▼ Longitudinal relaxation (T₁) contrast in MRI is important for studying brain morphology and is widely used in clinical applications. Although MRI only detects signals from water hydrogen (¹H) protons (WPs), T₁ contrast is known to be influenced by other species of ¹H protons, including those in macromolecules (MPs), such as lipids and proteins, through magnetization transfer (MT) between WPs and MPs. This complicates the use and quantification of T₁ contrast for studying the underlying tissue composition and the physiology of the brain. MT contributes to T₁ contrast to an extent that is generally dependent on MT kinetics, as well as the concentration and NMR spectral properties of MPs. However, the MP spectral properties and MT kinetics are both difficult to measure directly, as the signal from MPs is generally invisible to MRI. Therefore, to investigate MT kinetics and further quantify T₁ contrast, we first developed a reliable way to indirectly measure the MP fraction and their exchange rate with WPs, with minimal dependence on the spectral properties of MPs. For this purpose, we used brief, high-power radiofrequency (RF) NMR excitation pulses to almost completely saturate the magnetization of MPs. Based on this, both MT kinetics and the contribution of MPs to T₁ contrast through MT were studied. The thus obtained knowledge allowed us to subsequently infer the spectral properties of MPs by applying low-power, frequency-selective off-resonance RF pulses and measuring the offset-frequency dependent effect of MPs on the WP MRI signal. A two-pool exchange model was used in both cases to account for direct effects of the RF pulse on WP magnetization. Consistent with earlier works using MRI at low-field and post-mortem analysis of brain tissue, our novel measurement approach found that MPs constitute an up to 27% fraction of the total ¹H protons in human brain white matter, and their spectrum follows a super-Lorentzian line with a T₂ of 9.6±0.6 μs and a resonance frequency centered at -2.58±0.05 ppm, at 7 T. T₁ contrast was found to be dominated by MP fraction, with iron only modestly contributing even in the iron-rich regions of brain. Advisors/Committee Members: Anlage, Steven M. (advisor).

Subjects/Keywords: Physics; Medical imaging; Biophysics; contrast mechanism; longitudinal relaxation; macromolecular proton; magnetization transfer; MRI; t1 relaxation

…macromolecular protons magnetic resonance imaging magnetization transfer magnetization transfer ratio… …Effects of Magnetization Transfer on the T1 Contrast of Human Brain White Matter… …76 Chapter 4: Study of Magnetization Transfer and Macromolecular Proton T2 in Marmoset… …exchange saturation transfer cerebrospinal fluid X-ray computed tomography echo planar imaging… …significance and previous studies of T1 contrast and magnetization transfer (MT) associated…

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Jiang, X. (2017). QUANTITATIVE STUDY OF LONGITUDINAL RELAXATION (T₁) CONTRAST MECHANISMS IN BRAIN MRI. (Thesis). University of Maryland. Retrieved from http://hdl.handle.net/1903/19315

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Jiang, Xu. “QUANTITATIVE STUDY OF LONGITUDINAL RELAXATION (T₁) CONTRAST MECHANISMS IN BRAIN MRI.” 2017. Thesis, University of Maryland. Accessed March 03, 2021. http://hdl.handle.net/1903/19315.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Jiang, Xu. “QUANTITATIVE STUDY OF LONGITUDINAL RELAXATION (T₁) CONTRAST MECHANISMS IN BRAIN MRI.” 2017. Web. 03 Mar 2021.

Vancouver:

Jiang X. QUANTITATIVE STUDY OF LONGITUDINAL RELAXATION (T₁) CONTRAST MECHANISMS IN BRAIN MRI. [Internet] [Thesis]. University of Maryland; 2017. [cited 2021 Mar 03]. Available from: http://hdl.handle.net/1903/19315.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Jiang X. QUANTITATIVE STUDY OF LONGITUDINAL RELAXATION (T₁) CONTRAST MECHANISMS IN BRAIN MRI. [Thesis]. University of Maryland; 2017. Available from: http://hdl.handle.net/1903/19315

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

15. Wang, Charlie, Wang. High Energy Phosphate Metabolism Measurement by Phosphorus-31 Magnetic Resonance Fingerprinting.

Degree: PhD, Biomedical Engineering, 2018, Case Western Reserve University School of Graduate Studies

URL: http://rave.ohiolink.edu/etdc/view?acc_num=case1509364666422789

► Adenosine Triphosphate (ATP) serves as the universal currency of energy in cellular systems. Hydrolysis of ATP thermodynamically drives the majority of cellular processes fundamental to… (more)

▼ Adenosine Triphosphate (ATP) serves as the universal currency of energy in cellular systems. Hydrolysis of ATP thermodynamically drives the majority of cellular processes fundamental to life. The existence of a fast and robust method to observe ATP and its reactions in vivo would have profound applications both in the clinical diagnosis of metabolic abnormalities, and in the evaluation of therapies. Phosphorus-31 (³¹P) spectroscopy is the only modality capable of non-invasive non-destructive in vivo detection of ATP and its reactions. However, ³¹P spectroscopy methods are often challenging to perform due to two reasons. First, the instruments have an inherently low sensitivity to the biological signal. Second, conventional ³¹P spectroscopy methods have emphasized mathematical tractability rather than optimal signal detection. Consequently, ³¹P spectroscopy methods require long experiment times, and this has precluded their use in many applications. In this thesis, a new acquisition paradigm, the Magnetic Resonance Fingerprinting (MRF) framework, was applied to ³¹P spectroscopy method design in order to shorten experiment times. By prioritizing signal detection over mathematical tractability, the methods designed in this thesis sought to overcome the limitations imposed by instrument sensitivity and shorten experiment times. Success in this goal may enable new applications.Three main projects are described in this thesis. First, the MRF framework based ³¹P-MRF method was used to obtain efficient and simultaneous quantification of T₁ relaxation time and concentration of multiple metabolites. This method was tested in simulation and validated ex-vivo. Second, sensitivity to magnetization transfer (MT) effects between phosphocreatine (PCr) and ATP was added to the ³¹P-MRF method to measure the in vivo chemical exchange rate of creatine kinase enzyme. This new method, the CK-MRF method, was assessed in vivo rat hindlimb. Finally, the ³¹P-MRF method was further adapted to additionally incorporate measurements of ATP synthesis and hydrolysis. This third method, the MT-MRF method, was assessed in both simulation and in vivo experiments. Advisors/Committee Members: Durand, Dominique (Committee Chair), Yu, Xin (Advisor).

Subjects/Keywords: Medical Imaging; Biomedical Engineering; Phosphorus-31 Spectroscopy; Magnetization Transfer; Phosphate Metabolism; Magnetic Resonance Fingerprinting

…magnetization transfer (MT) effects between phosphocreatine (PCr) and ATP was… …leveraging the phenomena of magnetization transfer (MT) that accompanies all chemical… …Measurement by Magnetization Transfer encoded MRS The most common method to quantify metabolism… …rates, particularly the CK rate constant, is the magnetization transfer method (MT-MRS… …Furthermore, 31P Magnetization Transfer encoded MRS (MT-MRS) methods are able to…

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Wang, Charlie, W. (2018). High Energy Phosphate Metabolism Measurement by Phosphorus-31 Magnetic Resonance Fingerprinting. (Doctoral Dissertation). Case Western Reserve University School of Graduate Studies. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=case1509364666422789

Chicago Manual of Style (16^th Edition):

Wang, Charlie, Wang. “High Energy Phosphate Metabolism Measurement by Phosphorus-31 Magnetic Resonance Fingerprinting.” 2018. Doctoral Dissertation, Case Western Reserve University School of Graduate Studies. Accessed March 03, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=case1509364666422789.

MLA Handbook (7^th Edition):

Wang, Charlie, Wang. “High Energy Phosphate Metabolism Measurement by Phosphorus-31 Magnetic Resonance Fingerprinting.” 2018. Web. 03 Mar 2021.

Vancouver:

Wang, Charlie W. High Energy Phosphate Metabolism Measurement by Phosphorus-31 Magnetic Resonance Fingerprinting. [Internet] [Doctoral dissertation]. Case Western Reserve University School of Graduate Studies; 2018. [cited 2021 Mar 03]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=case1509364666422789.

Council of Science Editors:

Wang, Charlie W. High Energy Phosphate Metabolism Measurement by Phosphorus-31 Magnetic Resonance Fingerprinting. [Doctoral Dissertation]. Case Western Reserve University School of Graduate Studies; 2018. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=case1509364666422789

University of Florida

16. Bryant, Nathan. Noninvasive Characterization of Skeletal Muscle Damage and Repair in Murine Models of Muscular Dystrophy.

Degree: PhD, Medical Sciences - Physiology and Pharmacology (IDP), 2010, University of Florida

URL: https://ufdc.ufl.edu/UFE0041231

► The muscular dystrophies represent a class of devastating neuromuscular diseases that lead to the rapid wasting of muscle. Currently, there is no cure for muscular… (more)

▼ The muscular dystrophies represent a class of devastating neuromuscular diseases that lead to the rapid wasting of muscle. Currently, there is no cure for muscular dystrophy. Duchenne muscular dystrophy is one of the most devastating forms of muscular dystrophy resulting rapid progression and loss of ambulation in the early teenage years. Eventually the disease will prove to be fatal, due to both respiratory and cardiac muscle failure. Current invasive assays, such as muscle biopsy, are limited in their ability to accurately represent the entire tissue. The heterogeneous distribution, both spatially and temporally, of damaged and regenerating muscle fibers in the presence of fibrosis and fatty tissue infiltration makes biopsy much less reliable until later stages when the entire muscle is uniformly involved. In contrast, noninvasive imaging methods, such as magnetic resonance imaging (MRI), have the advantage of noninvasive detection of tissue pathology in three dimensions. A wide range of endogenous MRI contrast methods provides tools for researchers and clinicians to locate pathological features like muscle damage, edema, atrophy, and fat infiltration but most of these have been used in a purely qualitative manner. With this in mind, I set out to establish several working models of muscle damage, repair, and therapeutic correction in animal models of muscular dystrophy in order to develop effective monitoring and quantitative assessment protocols using MRI. I established that transverse relaxation (T2) is a consistent indicator of sarcolemmal damage in dystrophic skeletal muscle in both Duchenne and limb-girdle models of muscular dystrophy. I also explored the multi-exponential nature of muscle tissue T2 and its relationship to muscle damage. Taking it a step further, I studied changes in myofiber structure noninvasively using diffusion weighted imaging follow eccentric damage from downhill running. The use of diffusion tensor imaging (DTI) provided detailed insight into the underlying changes occurring over the throughout a two week period post injury. Ultimately, the muscle exhausts it ability to undergo this regenerative phase and its contractile tissue is replaced by fibro-fatty tissue. Unfortunately, fibrosis is extremely difficult to directly image, due to its extremely short transverse relaxation times. Therefore, I investigated an alternative approach to image tightly bound water molecules associated with tissue fibrosis. Magnetization transfer (MT) allows for the indirect imaging of fibrosis by looking at the proton MT between a free liquid pool and a macromolecular bound pool, of which, collagen is a major component in fibrosis. Combining these different basic MR imaging properties of muscle, I developed a multimodal approach to gain new prospectives in monitoring disease progression and detecting efficacy of potential treatments in animal models of muscular dystrophy. ( en ) Advisors/Committee Members: Walter, Glenn A. (committee chair), Vandenborne, Krista (committee member), Blackband, Stephen J. (committee member), Byrne, Barry J. (committee member), Johnson, Sally (committee member).

Subjects/Keywords: Fibrosis; Flood damage; Imaging; Magnetic resonance imaging; Magnetization; Muscle tissues; Muscles; Muscular dystrophies; Signals; Skeletal muscle; aav, damage, diffussion, dmd, dystrophy, lgmd, magnetization, mdx, mri, muscular, noninvasive, repair, t2, transfer

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Bryant, N. (2010). Noninvasive Characterization of Skeletal Muscle Damage and Repair in Murine Models of Muscular Dystrophy. (Doctoral Dissertation). University of Florida. Retrieved from https://ufdc.ufl.edu/UFE0041231

Chicago Manual of Style (16^th Edition):

Bryant, Nathan. “Noninvasive Characterization of Skeletal Muscle Damage and Repair in Murine Models of Muscular Dystrophy.” 2010. Doctoral Dissertation, University of Florida. Accessed March 03, 2021. https://ufdc.ufl.edu/UFE0041231.

MLA Handbook (7^th Edition):

Bryant, Nathan. “Noninvasive Characterization of Skeletal Muscle Damage and Repair in Murine Models of Muscular Dystrophy.” 2010. Web. 03 Mar 2021.

Vancouver:

Bryant N. Noninvasive Characterization of Skeletal Muscle Damage and Repair in Murine Models of Muscular Dystrophy. [Internet] [Doctoral dissertation]. University of Florida; 2010. [cited 2021 Mar 03]. Available from: https://ufdc.ufl.edu/UFE0041231.

Council of Science Editors:

Bryant N. Noninvasive Characterization of Skeletal Muscle Damage and Repair in Murine Models of Muscular Dystrophy. [Doctoral Dissertation]. University of Florida; 2010. Available from: https://ufdc.ufl.edu/UFE0041231

17. Παπαδάκη, Ευφροσύνη. Μελέτη της σκλήρυνσης κατά πλάκας με νεότερες τεχνικές μαγνητικής τομογραφίας.

Degree: 2004, University of Crete (UOC); Πανεπιστήμιο Κρήτης

URL: http://hdl.handle.net/10442/hedi/15835

Subjects/Keywords: Σκλήρυνση κατά πλάκας; Μαγνητική τομογραφία; Τεχνική μεταφοράς μαγνήτισης; Τεχνική κυτταρικής διάχυσης; Τεχνική αιματικής διήθησης; Multiple sclerosis; Magnetic resonance imaging; Magnetization transfer imaging technique; Diffusion-weighted imaging technique; Perfusion-weighted imaging technique

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Παπαδάκη, . �. (2004). Μελέτη της σκλήρυνσης κατά πλάκας με νεότερες τεχνικές μαγνητικής τομογραφίας. (Thesis). University of Crete (UOC); Πανεπιστήμιο Κρήτης. Retrieved from http://hdl.handle.net/10442/hedi/15835

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Παπαδάκη, Ευφροσύνη. “Μελέτη της σκλήρυνσης κατά πλάκας με νεότερες τεχνικές μαγνητικής τομογραφίας.” 2004. Thesis, University of Crete (UOC); Πανεπιστήμιο Κρήτης. Accessed March 03, 2021. http://hdl.handle.net/10442/hedi/15835.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Παπαδάκη, Ευφροσύνη. “Μελέτη της σκλήρυνσης κατά πλάκας με νεότερες τεχνικές μαγνητικής τομογραφίας.” 2004. Web. 03 Mar 2021.

Vancouver:

Παπαδάκη �. Μελέτη της σκλήρυνσης κατά πλάκας με νεότερες τεχνικές μαγνητικής τομογραφίας. [Internet] [Thesis]. University of Crete (UOC); Πανεπιστήμιο Κρήτης; 2004. [cited 2021 Mar 03]. Available from: http://hdl.handle.net/10442/hedi/15835.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Παπαδάκη �. Μελέτη της σκλήρυνσης κατά πλάκας με νεότερες τεχνικές μαγνητικής τομογραφίας. [Thesis]. University of Crete (UOC); Πανεπιστήμιο Κρήτης; 2004. Available from: http://hdl.handle.net/10442/hedi/15835

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

18. Thiessen, Jonathan. Development and application of quantitative MRI methods for assessing white matter integrity in the mouse brain.

Degree: Physics and Astronomy, 2012, University of Manitoba

URL: http://hdl.handle.net/1993/9221

► Healthy white matter in the brain and spinal cord is composed primarily of myelinated axons and glial cells. Myelinated axons transfer information between the peripheral… (more)

▼ Healthy white matter in the brain and spinal cord is composed primarily of myelinated axons and glial cells. Myelinated axons transfer information between the peripheral nervous system and the central nervous system (CNS) as well as between centres within the CNS. Demyelination, a hallmark of neurodegenerative autoimmune diseases such as multiple sclerosis (MS), can cause nerve damage and degrade signal propagation. Magnetic resonance imaging (MRI) methods thought to assess myelin integrity and the structural integrity of axons are improving both the diagnosis and understanding of white matter diseases such as MS. Current methods, however, are sensitive to many different pathologies, making the interpretation of individual MRI results difficult. For this dissertation, several quantitative MRI methods were developed and compared, including single component T1 and T2 relaxometry, multicomponent T2 relaxometry, diffusion tensor imaging (DTI), and quantitative magnetization transfer imaging (qMTI). These methods were tested on agarose gels, fixed rat spinal cords, healthy control mice, and the cuprizone mouse model of demyelination. Quantitative MRI measurements were correlated to ultrastructural measurements of white matter to determine the influence myelin content and axonal structure have on different MRI methods. Cellular distributions measured in electron micrographs of the corpus callosum correlated strongly to several different quantitative MRI metrics. The largest Spearman correlation coefficient varied depending on cellular type: longitudinal relaxation rates (RA/T1) vs. the myelinated axon fraction ( r = 0.90/-0.90), the qMTI-derived bound pool fraction (f) vs. the myelin sheath fraction ( r = 0.93), and the DTI-derived axial diffusivity vs. the non-myelinated cell fraction (r = 0.92). Using Pearson’s correlation coefficient, f was strongly correlated to the myelin sheath fraction (r = 0.98) with a linear equation predicting myelin content (5.37f −0.25). Of the calculated MRI metrics, f was the strongest indicator of myelin content while longitudinal relaxation rates and diffusivity measurements were the strongest indicators of changes in tissue structure. Multiparametric MRI measurements of relaxation, diffusion, and magnetization transfer give a more complete picture of white matter integrity. Advisors/Committee Members: Martin, Melanie (Physics and Astronomy) (supervisor), Gericke, Michael (Physics and Astronomy) King, Scott (Physics and Astronomy) Gough, Kathy (Chemistry) Kozlowski, Piotr (Physics and Astronomy, University of British Columbia) (examiningcommittee).

Subjects/Keywords: magnetic resonance imaging; diffusion tensor imaging; magnetization transfer imaging; relaxometry; demyelination; cuprizone; corpus callosum; myelin; electron microscopy; multiple sclerosis; white matter; image processing

…3.3 Magnetization Transfer Imaging . . . . . . . . . . . . . 3.3.1 Pulsed Magnetization… …Transfer Imaging . . . . 3.3.2 Two-Pool Model of Magnetization Transfer . . 3.3.3 qMTI Metrics… …magnetization transfer imaging (MTI) or multicomponent T2 analysis (mcT2 ) [… …such as myelin (e.g. magnetization transfer imaging, MTI). T1 and T2 Relaxometry… …x28;μm2/ms) 0 1 0 Magnetization Transfer Imaging ƒ RA RM0A 0 0.2 0 (s-1)…

10 more images…

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Thiessen, J. (2012). Development and application of quantitative MRI methods for assessing white matter integrity in the mouse brain. (Thesis). University of Manitoba. Retrieved from http://hdl.handle.net/1993/9221

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Thiessen, Jonathan. “Development and application of quantitative MRI methods for assessing white matter integrity in the mouse brain.” 2012. Thesis, University of Manitoba. Accessed March 03, 2021. http://hdl.handle.net/1993/9221.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Thiessen, Jonathan. “Development and application of quantitative MRI methods for assessing white matter integrity in the mouse brain.” 2012. Web. 03 Mar 2021.

Vancouver:

Thiessen J. Development and application of quantitative MRI methods for assessing white matter integrity in the mouse brain. [Internet] [Thesis]. University of Manitoba; 2012. [cited 2021 Mar 03]. Available from: http://hdl.handle.net/1993/9221.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Thiessen J. Development and application of quantitative MRI methods for assessing white matter integrity in the mouse brain. [Thesis]. University of Manitoba; 2012. Available from: http://hdl.handle.net/1993/9221

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

19. Nunes Dourado de Carvalho, Victor. Dipolar order relaxation (T1D) in myelin : a combined inhomogeneous MT (ihMT) MRI and Jeener-Broekaert NMR approach : Relaxation dipolaire (T1D) dans la myéline : une approche par IRM du transfert d’aimantation inhomogène (ihMT) et RMN Jeener-Broekaert.

Degree: Docteur es, Neurosciences, 2020, Aix Marseille Université

URL: http://www.theses.fr/2020AIXM0195

►

Le transfert d’aimantation inhomogène (ihMT) est une technique IRM qui permet d’accéder in vivo au contenu de myéline dans le système nerveux central. La technique… (more)

▼

Le transfert d’aimantation inhomogène (ihMT) est une technique IRM qui permet d’accéder in vivo au contenu de myéline dans le système nerveux central. La technique ihMT met en évidence des effets d’ordre dipolaire pondérés par le temps de relaxation dipolaire, T1D. T1D est modulé par la dynamique moléculaire, fournissant néanmoins une sensibilité plus accrue aux processus liés aux mouvements lents. Accéder aux valeurs de T1D représente une nouvelle voie d’investigation dans la caractérisation des tissus biologiques et des pathologies associées. IhMT est hautement spécifique de la myéline, et pourrait être utilisée in vivo pour aider au diagnostic et au suivi des patients atteints de sclérose en plaques. Des expériences ont suggéré l’existence de plusieurs composantes T1D dans les tissus myélinisés probablement due à une mobilité moléculaire hétérogène. Une méthode de RMN, technique Jeener-Broekaert, a été utilisée dans ce travail afin de mieux appréhender la relaxation T1D dans les membranes. Avec cette séquence, une relaxation T1D multi-composante a été observé dans des membranes lipidiques synthétiques, simulant la myéline. Ce travail propose un nouveau modèle quantitatif ihMT permettant de considérer plusieurs composantes T1Ds. Des cartes T1D quantitatives ont ainsi été générées. L’application du modèle proposé a permis de révéler l’existence de deux composantes T1Ds, une courte de l’ordre de 500 μs et une longue de l’ordre de 10 ms, dans la moelle épinière de rat. La mesure combinée de T1D par RMN JB et IRM ihMT permettra de caractériser plus précisément les composantes de composition, structure et dynamique moléculaire des membranes contribuant au signal ihMT.

Inhomogeneous magnetization transfer (ihMT) is a MRI technique that enables accurate measurement of myelin content in the central nervous system in vivo. ihMT highlights the dipolar order effects and is weighted by the associated relaxation time T1D. T1D is modulated by molecular dynamics, however it provides additional sensitivity to slow motional processes. Hence assessing T1D is important to add new information to characterize biological tissues and associated pathophysiology. ihMT and other MRI techniques can be used to evaluate myelin in vivo, and help diagnosis and follow-up of multiple sclerosis patients. New experiments have suggested that myelinated tissues and membranes would exhibit multiple T1D components probably due to a heterogeneous molecular mobility and relatively slow magnetization mixing mechanisms. To better understand T1D relaxation, the presented work uses a NMR method, the Jeener-Broekaert sequence. With this sequence, multi-T1D relaxation was observed on synthetic lipid membranes, surrogate models of myelin. This work proposes a new ihMT model with two dipolar order reservoirs and associated T1Ds. Quantitative T1D maps were generated. Implementation of the proposed model found short and long T1D on the order of 500 μs and 10 ms, respectively, in fixed rat spinal cord. Combining NMR and MRI assessments of T1D may help understand…

Advisors/Committee Members: Duhamel, Guillaume (thesis director), Thureau, Pierre (thesis director).

Subjects/Keywords: Temps de relaxation dipolaire (T1D); Transfert d'aimantation inhomogène (ihMT); Contrast d’IRM; Séquence Jeener-Broekaert; Myéline; Lipides; Dynamique moléculaire; Résonance Magnétique Nucléaire (RMN); Imagerie par Résonance Magnétique (IRM).; Dipolar relaxation time (T1D); Inhomogeneous magnetization transfer (ihMT); MRI contrast; Jeener-Broekaert sequence; Myelin; Lipids; Molecular dynamics; Nuclear Magnetic Resonance (NMR); Magnetic Resonance Imaging (MRI).

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Nunes Dourado de Carvalho, V. (2020). Dipolar order relaxation (T1D) in myelin : a combined inhomogeneous MT (ihMT) MRI and Jeener-Broekaert NMR approach : Relaxation dipolaire (T1D) dans la myéline : une approche par IRM du transfert d’aimantation inhomogène (ihMT) et RMN Jeener-Broekaert. (Doctoral Dissertation). Aix Marseille Université. Retrieved from http://www.theses.fr/2020AIXM0195

Chicago Manual of Style (16^th Edition):

Nunes Dourado de Carvalho, Victor. “Dipolar order relaxation (T1D) in myelin : a combined inhomogeneous MT (ihMT) MRI and Jeener-Broekaert NMR approach : Relaxation dipolaire (T1D) dans la myéline : une approche par IRM du transfert d’aimantation inhomogène (ihMT) et RMN Jeener-Broekaert.” 2020. Doctoral Dissertation, Aix Marseille Université. Accessed March 03, 2021. http://www.theses.fr/2020AIXM0195.

MLA Handbook (7^th Edition):

Nunes Dourado de Carvalho, Victor. “Dipolar order relaxation (T1D) in myelin : a combined inhomogeneous MT (ihMT) MRI and Jeener-Broekaert NMR approach : Relaxation dipolaire (T1D) dans la myéline : une approche par IRM du transfert d’aimantation inhomogène (ihMT) et RMN Jeener-Broekaert.” 2020. Web. 03 Mar 2021.

Vancouver:

Nunes Dourado de Carvalho V. Dipolar order relaxation (T1D) in myelin : a combined inhomogeneous MT (ihMT) MRI and Jeener-Broekaert NMR approach : Relaxation dipolaire (T1D) dans la myéline : une approche par IRM du transfert d’aimantation inhomogène (ihMT) et RMN Jeener-Broekaert. [Internet] [Doctoral dissertation]. Aix Marseille Université 2020. [cited 2021 Mar 03]. Available from: http://www.theses.fr/2020AIXM0195.

Council of Science Editors:

Nunes Dourado de Carvalho V. Dipolar order relaxation (T1D) in myelin : a combined inhomogeneous MT (ihMT) MRI and Jeener-Broekaert NMR approach : Relaxation dipolaire (T1D) dans la myéline : une approche par IRM du transfert d’aimantation inhomogène (ihMT) et RMN Jeener-Broekaert. [Doctoral Dissertation]. Aix Marseille Université 2020. Available from: http://www.theses.fr/2020AIXM0195

20. Παπανικολάου, Νικόλαος. Ανάπτυξη και κλινική αξιολόγηση νέων απεικονιστικών μεθόδων του γαστρεντερικού σωλήνα με μαγνητική τομογραφία.

Degree: 2005, University of Crete (UOC); Πανεπιστήμιο Κρήτης

URL: http://hdl.handle.net/10442/hedi/16123

Subjects/Keywords: Μαγνητική τομογραφία; Ακολουθίες παλμών; Σκιαγραφικές ουσίες; Συμβατική εντερόκλυση; Νόσος Crohn; Μεταφορά μαγνήτισης; Μαγνητική ακτινοσκόπηση; Ιστικός χαρακτηρισμός; Magnetic resonance imaging; Pulse sequences; Contpast media; Conventional enteroclysis; Crohn's disease; Magnetization transfer; MR fluoroscopy; Tissue characterization

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Παπανικολάου, . �. (2005). Ανάπτυξη και κλινική αξιολόγηση νέων απεικονιστικών μεθόδων του γαστρεντερικού σωλήνα με μαγνητική τομογραφία. (Thesis). University of Crete (UOC); Πανεπιστήμιο Κρήτης. Retrieved from http://hdl.handle.net/10442/hedi/16123

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Παπανικολάου, Νικόλαος. “Ανάπτυξη και κλινική αξιολόγηση νέων απεικονιστικών μεθόδων του γαστρεντερικού σωλήνα με μαγνητική τομογραφία.” 2005. Thesis, University of Crete (UOC); Πανεπιστήμιο Κρήτης. Accessed March 03, 2021. http://hdl.handle.net/10442/hedi/16123.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Παπανικολάου, Νικόλαος. “Ανάπτυξη και κλινική αξιολόγηση νέων απεικονιστικών μεθόδων του γαστρεντερικού σωλήνα με μαγνητική τομογραφία.” 2005. Web. 03 Mar 2021.

Vancouver:

Παπανικολάου �. Ανάπτυξη και κλινική αξιολόγηση νέων απεικονιστικών μεθόδων του γαστρεντερικού σωλήνα με μαγνητική τομογραφία. [Internet] [Thesis]. University of Crete (UOC); Πανεπιστήμιο Κρήτης; 2005. [cited 2021 Mar 03]. Available from: http://hdl.handle.net/10442/hedi/16123.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Παπανικολάου �. Ανάπτυξη και κλινική αξιολόγηση νέων απεικονιστικών μεθόδων του γαστρεντερικού σωλήνα με μαγνητική τομογραφία. [Thesis]. University of Crete (UOC); Πανεπιστήμιο Κρήτης; 2005. Available from: http://hdl.handle.net/10442/hedi/16123

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

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Open Access Theses and Dissertations