2016 AAPM Annual Meeting
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Session Title: MRgRT
Question 1: Which is the main contributor to the MR image distortion field for RT applications?
Reference:Doran et al, Phys Med Biol 50, 1343–1361, 2005
Choice A:MR main field (B0) inhomogeneity.
Choice B:Chemical shift.
Choice C:Tissue susceptibility.
Choice D:Imaging gradient non-linearity.
Choice E:Motion.
Question 2: For MR-guided RT systems, which MR-related test is new and has to be added to the QC routine?
Reference:Lagendijk et al, Phys Med Biol 59, R349-R369, 2014
Choice A:Magnetic field drift.
Choice B:Imaging-to-treatment isocenter co-registration.
Choice C:Center frequency.
Choice D:Image uniformity.
Choice E:Ghosting.
Question 3: Based on FMEA analysis, the following component of the real-time, online adaptive radiotherapy process carries the most potential critical failure risk:
Reference:Noel, Camille E., et al. "Process-based quality management for clinical implementation of adaptive radiotherapy." Medical physics 41.8 (2014): 081717.
Choice A:Target/structure delineation.
Choice B:Data transfer.
Choice C:Daily patient localization.
Choice D:Pre-treatment patient-specific quality assurance.
Question 4: Pre-treatment IMRT QA is the most effective method of quality control for radiotherapy and is therefore a limiting factor in choosing ART strategies.
Reference:Ford, Eric C., et al. "Quality control quantification (QCQ): a tool to measure the value of quality control checks in radiation oncology." International Journal of Radiation Oncology* Biology* Physics 84.3 (2012): e263-e269
Choice A:True.
Choice B:False.
Question 5: In Body MRI used in radiation oncology, which of the following is correct?
Reference:A. Zhuo J, Gullapalli RP: MR Artifacts, Safety, and Quality Control. RadioGraphics 2006, 26:275-297 http://dx.doi.org/10.1148/rg.261055134 B. Schmidt M, Panek R, Scurr E, et al: Anatomical and Functional MRI for Radiotherapy Planning of Head and Neck Cancers. MAGNETOM Flash 2015: 64-68; www.siemens.com/magnetom-world C. Bonekamp D, Jacobs MA, et al: Advancements in MRI of the Prostate. Radiographics. 2011; 31: 677–703 http://dx.doi.org/10.1118/1.4903262
Choice A:In abdominal MRI, the body motion artifacts can be drastically reduced using breath-hold or respiratory-ordered phase encoding techniques.
Choice B:For MRI used for treatment planning, a head and neck cancer patient shall be scanned in diagnostic position and centered at the superior end of the segment.
Choice C:Common MRI sequences used for prostate cancer include T2WI, DWI-ADC (diffusion weighted, apparent diffusion coefficient), and DCE-MRI (dynamic contract-enhanced).
Choice D:Both A and C.
Choice E:All of the above.
Question 6: If the metal immobilization pins are used during MR head scan, which the following may show the greatest geometric distortion:
Reference:H. Nakazawa, Y. Mori, O. Yamamuro, et al: "Geometric accuracy of 3D coordinates of the Leksell stereotactic skull frame in 1.5 Tesla- and 3.0 Tesla-magnetic resonance imaging: a comparison of three different fixation screw materials" J Radiat Res. 2014 November; 55(6): 1184–1191. Published online 2014 July 17. doi: 10.1093/jrr/rru064
Choice A:Tungsten in 1.5-T MRI
Choice B:Aluminum in 1.5-T MRI
Choice C:Titanium in 1.5-T MRI
Choice D:Titanium in 3.0-T MRI
Choice E:Aluminum in 3.0-T MRI
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