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You searched for subject:( tracked ultrasound). Showing records 1 – 2 of 2 total matches.

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Queens University

1. Chen, Kuiran. An Automated Ultrasound Calibration Framework Incorporating Elevation Beamwidth for Tracked Ultrasound Interventions .

Degree: Computing, 2012, Queens University

Image-guided surgeries employ advanced imaging and computing technologies to assist the surgeon when direct visualization is inadequate or unavailable. As modern surgeries continue to move toward minimally invasive procedures, tracked ultrasound (US), an emerging technology that uniquely combines US imaging and position tracking, has been increasingly used for intraoperative guidance in surgical interventions. The intrinsic accuracy of a tracked US system is primarily determined by a unique procedure called ``probe calibration", where a spatial registration between the coordinate systems of the transducer (provided by a tracking device affixed to the probe) and the US image plane must be established prior to imaging. Inaccurate system calibration causes misalignments between the US image and the surgical end-effectors, which may directly contribute to treatment failure. The probe calibration quality is further reduced by the "elevation beamwidth" or "slice thickness", a unique feature of the ultrasound beam pattern that gives rise to localization errors and imaging uncertainties. In this thesis, we aim to provide an automated, pure-computation-based, intraoperative calibration solution that also incorporates the slice thickness to improve the calibration accuracy, precision and reliability. The following contributions have been made during the course of this research. First, we have designed and developed an automated, freehand US calibration system with instant feedback on its calibration accuracy. The system was able to consistently achieve submillimeter accuracy with real-time performance. Furthermore, we have developed a novel beamwidth-weighted calibration framework (USB-FW) that incorporates US slice thickness to improve the estimation of calibration parameters. The new framework provides an effective means of quality control for calibration results. Extensive phantom validation demonstrated that USB-FW introduces statistically significant reduction (p = 0.001) in the calibration errors and produces calibration outcomes that are less variable than a conventional, non-beamwidth-weighted calibration. Finally, we were the first to introduce an automated, intraoperative Transrectal Ultrasound (TRUS) calibration technology for needle guidance in prostate brachytherapy. Our tests with multiple commercial TRUS scanners and brachytherapy stepper systems demonstrated that the proposed method is practical in use and can achieve high calibration accuracy, precision and robustness.

Subjects/Keywords: ultrasound elevation beamwidth; ultrasound slice thickness; probe calibration; image-guided surgery; tracked ultrasound

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

APA (6th Edition):

Chen, K. (2012). An Automated Ultrasound Calibration Framework Incorporating Elevation Beamwidth for Tracked Ultrasound Interventions . (Thesis). Queens University. Retrieved from http://hdl.handle.net/1974/7614

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):

Chen, Kuiran. “An Automated Ultrasound Calibration Framework Incorporating Elevation Beamwidth for Tracked Ultrasound Interventions .” 2012. Thesis, Queens University. Accessed March 29, 2020. http://hdl.handle.net/1974/7614.

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

MLA Handbook (7th Edition):

Chen, Kuiran. “An Automated Ultrasound Calibration Framework Incorporating Elevation Beamwidth for Tracked Ultrasound Interventions .” 2012. Web. 29 Mar 2020.

Vancouver:

Chen K. An Automated Ultrasound Calibration Framework Incorporating Elevation Beamwidth for Tracked Ultrasound Interventions . [Internet] [Thesis]. Queens University; 2012. [cited 2020 Mar 29]. Available from: http://hdl.handle.net/1974/7614.

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

Council of Science Editors:

Chen K. An Automated Ultrasound Calibration Framework Incorporating Elevation Beamwidth for Tracked Ultrasound Interventions . [Thesis]. Queens University; 2012. Available from: http://hdl.handle.net/1974/7614

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


Vanderbilt University

2. Conley, Rebekah Helene. A Comprehensive Framework for Image Guided Breast Surgery.

Degree: MS, Biomedical Engineering, 2015, Vanderbilt University

Unfortunately, the current re-excision rates for breast conserving surgeries due to positive margins average 20-40%. The high re-excision rates arise from difficulty in localizing tumor boundaries intraoperatively and lack of real time information on the presence of residual disease. The work presented here introduces the use of supine magnetic resonance (MR) images, digitization technology, and biomechanical models to investigate the capability of using an image guidance system to localize tumors intraoperatively. Two studies are presented in which preoperative supine MR images were registered to a mock intraoperative setup. In the mock intraoperative setup, a laser range scanner was used to digitize the breast surface and tracked ultrasound was used to digitize the chest wall and tumor. In the first study, a rigid registration was performed and validated using subsurface error metrics between the registered preoperative tumor and the intraoperative tumor as identified by tracked ultrasound. In the second study, a novel nonrigid correction technique was employed to correct for deformations occurring between the preoperative and intraoperative states. Tumor localizations by tracked ultrasound were again used to evaluate the fidelity of aligning preoperative MR tumor contours to physical patient space. Using our prototype image guided surgery platform, we were able to align intraoperative data with preoperative patient specific models with clinically relevant accuracy. Advisors/Committee Members: Michael I. Miga (chair), Robert L. Galloway (committee member).

Subjects/Keywords: nonrigid registration; tracked ultrasound; biomechanical models; image guided surgery; lumpectomy; breast conservation therapy

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

APA (6th Edition):

Conley, R. H. (2015). A Comprehensive Framework for Image Guided Breast Surgery. (Masters Thesis). Vanderbilt University. Retrieved from http://etd.library.vanderbilt.edu//available/etd-03192015-103733/ ;

Chicago Manual of Style (16th Edition):

Conley, Rebekah Helene. “A Comprehensive Framework for Image Guided Breast Surgery.” 2015. Masters Thesis, Vanderbilt University. Accessed March 29, 2020. http://etd.library.vanderbilt.edu//available/etd-03192015-103733/ ;.

MLA Handbook (7th Edition):

Conley, Rebekah Helene. “A Comprehensive Framework for Image Guided Breast Surgery.” 2015. Web. 29 Mar 2020.

Vancouver:

Conley RH. A Comprehensive Framework for Image Guided Breast Surgery. [Internet] [Masters thesis]. Vanderbilt University; 2015. [cited 2020 Mar 29]. Available from: http://etd.library.vanderbilt.edu//available/etd-03192015-103733/ ;.

Council of Science Editors:

Conley RH. A Comprehensive Framework for Image Guided Breast Surgery. [Masters Thesis]. Vanderbilt University; 2015. Available from: http://etd.library.vanderbilt.edu//available/etd-03192015-103733/ ;

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