Question 1: Which of following is true for respiratory-correlated 4D-MRI? |
Reference: | Respiratory-Correlated (RC) vs. Time-Resolved (TR) Four-Dimensional Magnetic Resonance Imaging (4DMRI) for Radiotherapy of Thoracic and Abdominal Cancer, Guang Li, Yilin Liu , Xingyu Nie , Front Oncol. 2019 Oct 11; 9:1024. PMID: 31681573 |
Choice A: | The fourth dimension is time |
Choice B: | The fourth dimension is phase/amplitude bin |
Choice C: | Is superior to 4D-CT in tumor contrast when imaging abdominal tumor motion |
Choice D: | b & c |
Question 2: What acquisition methods are used in 4D-MRI? |
Reference: | Nuts and bolts of 4D-MRI for radiotherapy, B Stemkens, E S Paulson, R H N Tijssen, Phys Med Biol. 2018 Oct 23;63(21):21TR01. PMID: 30272573 |
Choice A: | 2D/3D Cartesian |
Choice B: | 3D stack-of-stars |
Choice C: | 3D Radial |
Choice D: | all of above |
Question 3: 4D-CBCT typically requires a much longer scanning time than 3D-CBCT because |
Reference: | 1. Li, Tianfang, and Lei Xing. "Optimizing 4D cone-beam CT acquisition protocol for external beam radiotherapy." International Journal of Radiation Oncology* Biology* Physics 67.4 (2007): 1211-1219.
2. Zhang, Y., Yin, F. F., Pan, T., Vergalasova, I., & Ren, L. (2015). Preliminary clinical evaluation of a 4D-CBCT estimation technique using prior information and limited-angle projections. Radiotherapy and Oncology, 115(1), 22-29. |
Choice A: | 4D-CBCT needs to acquire adequate projections for each phase bin |
Choice B: | 4D-CBCT needs longer scanning time to average out the motion effects |
Choice C: | 4D-CBCT needs more projections to reduce the scatter artifacts |
Choice D: | 4D-CBCT uses longer scanning time to reduce the imaging dose |
Question 4: What’s the advantage of motion compensated 4D-CBCT reconstruction compared to simple FDK back-projection reconstruction? |
Reference: | Shieh, Chun‐Chien, et al. "SPARE: Sparse‐view reconstruction challenge for 4D cone‐beam CT from a 1‐min scan." Medical physics 46.9 (2019): 3799-3811. |
Choice A: | Faster speed |
Choice B: | Computationally less expensive |
Choice C: | Better scatter correction |
Choice D: | Less streak artifacts caused by under sampling |
Question 5: DDG PET/CT vs. Hardware gated PET/CT,which one is correct? |
Reference: | Walker MD, Morgan AJ, Bradley KM, McGowan DR. Data Driven Respiratory Gating Outperforms Device-Based Gating for Clinical FDG PET/CT. J Nucl Med. 2020. |
Choice A: | DDG PET/CT is better in image quality and lower in SUV than hardware gated PET/CT |
Choice B: | DDG PET/CT is better in image quality and higher in SUV than hardware gated PET/CT |
Choice C: | DDG PET/CT is worse in image quality and lower in SUV than hardware gated PET/CT |
Choice D: | DDG PET/CT is worse in image quality and higher in SUV than hardware gated PET/CT |
Question 6: In comparison of PET/CT followed by either average CT or repeat PET/CT to correct for misregistration between CT and PET, which one of the following is correct? |
Reference: | Pan T, Lu Y, Thomas MA, Liao Z, Luo D. New data-driven gated PET/CT free of misregistration artifacts. Int. J Radiat Oncol Biol Phys. 109(5): 1638-1646. 2021. PMCID: PMC7965243. |
Choice A: | Average CT was lower in CT dose and shorter in scan time than repeat PET/CT |
Choice B: | Average CT was lower in CT dose and longer in scan time than repeat PET/CT |
Choice C: | Average CT was higher in CT dose and shorter in scan time than repeat PET/CT |
Choice D: | Average CT was higher in CT dose and longer in scan time than repeat PET/CT |