Question 1: For a medical physicist not trained in MRI, preparing to work on an MRI simulator should include: |
Reference: | M Cao, K Padgett, Y Rong, “Are in-house diagnostic MR physicists necessary for clinical implementation of MRI guided radiotherapy?”, JACMP, 18:5:6-9, 2017.
M. Scmidt, G. Payne, “Radiotherapy planning using MRI”, Physics in Medicine and Biology, 60, R323-362, 2015.
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Choice A: | Training by the manufacturer. |
Choice B: | Seeking the services of a qualified MRI medical physicist. |
Choice C: | Understanding the challenges of using MRI in RT planning. |
Choice D: | A and C. |
Choice E: | A,B and C. |
Question 2: Which of the following statement is INCORRECT about MRI distortion for RT application? |
Reference: | Weygand J, Fuller CD, Ibbott GS, et al. Spatial Precision in Magnetic Resonance Imaging-Guided Radiation Therapy: The Role of Geometric Distortion. Int J Radiation Oncol Biol Phys, Vol. 95, No. 4, pp. 1304e1316, 2016. |
Choice A: | Geometric distortion correction algorithms must be validated and properly assessed before being implemented for RT applications. |
Choice B: | MRI distortion is MR pulse sequence dependent. |
Choice C: | Precision within 2 mm is desired. |
Choice D: | Patient related geometric distortion is more problematic. |
Choice E: | None of them. |
Question 3: When siting an MRI-Linac, what major difference(s) is/are recommended as compared to a conventional Linac? |
Reference: | Kanal, E., Barkovich, A.J., Bell, C., Borgstede, J.P., Bradley, W.G., Froelich, J.W., Gimbel, J.R., Gosbee, J.W., Kuhni‐Kaminski, E., Larson, P.A. and Lester, J.W., 2013. ACR guidance document on MR safe practices: 2013. Journal of Magnetic Resonance Imaging, 37(3), pp.501-530. |
Choice A: | Following American College of Radiology (ACR) MRI safety zones. |
Choice B: | Addition of a penetration panel. |
Choice C: | Elimination of reinforcing bars (rebar/steel) in the shielding. |
Choice D: | All of the above. |
Question 4: The electron return effect may cause an increase in dose at air/tissue interfaces. What is one treatment planning strategy to mitigate this effect? |
Reference: | Raaijmakers, A.J.E., Raaymakers, B.W. and Lagendijk, J.J., 2005. Integrating a MRI scanner with a 6 MV radiotherapy accelerator: dose increase at tissue–air interfaces in a lateral magnetic field due to returning electrons. Physics in Medicine & Biology, 50(7), p.1363. |
Choice A: | Turn the magnetic field off during treatment. |
Choice B: | Disable inhomogeneity corrections during dose calculation. |
Choice C: | Use more beams in the treatment plan design. |
Choice D: | Avoid having the beam traverse air when treatment planning. |
Question 5: Which of the following are the advantages of MRgRT system? |
Reference: | P Kupelian P, J-J Sonke, Magnetic Resonance–Guided Adaptive Radiotherapy: A Solution to the Future. Semin Radiat Oncol. 2014;24(3):227-232. doi:10.1016/j.semradonc.2014.02.01 |
Choice A: | Improved soft tissue contrast |
Choice B: | Soft tissue based gated treatment |
Choice C: | Effective online adaptive therapy |
Choice D: | Onboard functional imaging capability |
Choice E: | All of the above |
Question 6: The 5-Gauss line is: |
Reference: | E Kanal, JP Borgstede, AJ Barkovich, C Bell, WG. Bradley, JP Felmlee, JW Froelich, EM Kaminski, EK Keeler, JW Lester, EA Scoumis, LA Zaremba and MD Zinninge, American College of Radiology White Paper on MR Safety, American Journal of Roentgenology. 2002;178: 1335-1347. doi:10.2214/ajr.178.6.1781335 |
Choice A: | A pixel line in the matrix |
Choice B: | The magnetic field line territory within which the magnetic field can become harmful |
Choice C: | A catheter inserted into the femoral artery |
Choice D: | A geometric theorem |