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Title: SU-E-T-661: Quantitative MRI Assessment of a Novel Direction-Modulated Brachytherapy Tandem Applicator for Cervical Cancer

Abstract

Purpose: To quantitatively evaluate the MR image quality of a novel direction modulated brachytherapy (DMBT) tandem applicator for cervical cancer, using the clinical MRI scanning protocol for image guided brachytherapy. Methods: The tungsten alloy-based applicator was placed in a water phantom and clinical imaging protocol was performed. Axial images were acquired using 2D turbo-spin echo (TSE) T2-weighted sequence on a 1.5T GE 450w MR scanner and an 8-channel body coil. As multi-channel receiver coil was used, inhomogeneities in the B1 receive field must be considered before performing the quantification process. Therefore the applicator was removed from the phantom and the whole imaging session was performed again for the water phantom with the same parameters. Images from the two scans were then subtracted, resulting in a difference image that only shows the applicator with its surrounding magnetic susceptibility dipole artifact. Line profiles were drawn and plotted on the difference image at various angles and locations along the tandem. Full width at half maximum (FWHM) was measured at all the line profiles to quantify the extent of the artifact. Additionally, the extent of the artifact along the diameter of the tandem was measured at various angles and locations. Results: After removing themore » background inhomogeneities of the receiver coil, FWHM of the tandem measured 5.75 ± 0.35 mm (the physical tandem diameter is 5.4 mm). The average extent of the artifacts along the diameter of the tandem measured is 2.14 ± 0.56 mm. In contrast to CT imaging of the same applicator (not shown here), the tandem can be easily identified without additional correction algorithms. Conclusion: This work demonstrated that the novel DMBT tandem applicator has minimal susceptibility artifact in T2-weighted images employed in clinical practice for MRI-guided brachytherapy of cervical cancer.« less

Authors:
; ; ; ; ; ;  [1];  [1];  [2]
  1. Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada)
  2. (United States)
Publication Date:
OSTI Identifier:
22538169
Resource Type:
Journal Article
Resource Relation:
Journal Name: Medical Physics; Journal Volume: 42; Journal Issue: 6; Other Information: (c) 2015 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; BIOMEDICAL RADIOGRAPHY; BRACHYTHERAPY; IMAGES; MAGNETIC SUSCEPTIBILITY; NEOPLASMS; NMR IMAGING; PHANTOMS; UROGENITAL SYSTEM DISEASES; UTERUS

Citation Formats

Soliman, A, Elzibak, A, Fatemi, A, Safigholi, H, Leung, E, Ravi, A, Song, W, Han, D, and University of California, San Diego, La Jolla, CA. SU-E-T-661: Quantitative MRI Assessment of a Novel Direction-Modulated Brachytherapy Tandem Applicator for Cervical Cancer. United States: N. p., 2015. Web. doi:10.1118/1.4925024.
Soliman, A, Elzibak, A, Fatemi, A, Safigholi, H, Leung, E, Ravi, A, Song, W, Han, D, & University of California, San Diego, La Jolla, CA. SU-E-T-661: Quantitative MRI Assessment of a Novel Direction-Modulated Brachytherapy Tandem Applicator for Cervical Cancer. United States. doi:10.1118/1.4925024.
Soliman, A, Elzibak, A, Fatemi, A, Safigholi, H, Leung, E, Ravi, A, Song, W, Han, D, and University of California, San Diego, La Jolla, CA. Mon . "SU-E-T-661: Quantitative MRI Assessment of a Novel Direction-Modulated Brachytherapy Tandem Applicator for Cervical Cancer". United States. doi:10.1118/1.4925024.
@article{osti_22538169,
title = {SU-E-T-661: Quantitative MRI Assessment of a Novel Direction-Modulated Brachytherapy Tandem Applicator for Cervical Cancer},
author = {Soliman, A and Elzibak, A and Fatemi, A and Safigholi, H and Leung, E and Ravi, A and Song, W and Han, D and University of California, San Diego, La Jolla, CA},
abstractNote = {Purpose: To quantitatively evaluate the MR image quality of a novel direction modulated brachytherapy (DMBT) tandem applicator for cervical cancer, using the clinical MRI scanning protocol for image guided brachytherapy. Methods: The tungsten alloy-based applicator was placed in a water phantom and clinical imaging protocol was performed. Axial images were acquired using 2D turbo-spin echo (TSE) T2-weighted sequence on a 1.5T GE 450w MR scanner and an 8-channel body coil. As multi-channel receiver coil was used, inhomogeneities in the B1 receive field must be considered before performing the quantification process. Therefore the applicator was removed from the phantom and the whole imaging session was performed again for the water phantom with the same parameters. Images from the two scans were then subtracted, resulting in a difference image that only shows the applicator with its surrounding magnetic susceptibility dipole artifact. Line profiles were drawn and plotted on the difference image at various angles and locations along the tandem. Full width at half maximum (FWHM) was measured at all the line profiles to quantify the extent of the artifact. Additionally, the extent of the artifact along the diameter of the tandem was measured at various angles and locations. Results: After removing the background inhomogeneities of the receiver coil, FWHM of the tandem measured 5.75 ± 0.35 mm (the physical tandem diameter is 5.4 mm). The average extent of the artifacts along the diameter of the tandem measured is 2.14 ± 0.56 mm. In contrast to CT imaging of the same applicator (not shown here), the tandem can be easily identified without additional correction algorithms. Conclusion: This work demonstrated that the novel DMBT tandem applicator has minimal susceptibility artifact in T2-weighted images employed in clinical practice for MRI-guided brachytherapy of cervical cancer.},
doi = {10.1118/1.4925024},
journal = {Medical Physics},
number = 6,
volume = 42,
place = {United States},
year = {Mon Jun 15 00:00:00 EDT 2015},
month = {Mon Jun 15 00:00:00 EDT 2015}
}