| Question 1: A typical range of photon flux in clinical CT is: |
| Reference: | Persson, M., Bujila, R., Nowik, P., Andersson, H., Kull, L., Andersson, J., Bornefalk, H. and Danielsson, M., 2016. Upper limits of the photon fluence rate on CT detectors: case study on a commercial scanner. Medical physics, 43(7), pp.4398-4411. |
| Choice A: | 10^12 – 10^17 photons/ mm2 / s |
| Choice B: | 10^2 – 10^4 photons/ mm2 / s |
| Choice C: | 105 – 108 photons/ mm2/ s |
| Choice D: | 10^8 – 10^12 photons/ mm2 / s |
| Question 2: Pulse pileup in photon-counting detector leads mainly to: |
| Reference: | Danielsson, M., Persson, M. and Sjölin, M., 2021. Photon-counting x-ray detectors for CT. Physics in Medicine & Biology, 66(3), p.03TR01. |
| Choice A: | Reduced spatial resolution |
| Choice B: | Reduced CNR |
| Choice C: | Reduced spectral resolution |
| Choice D: | Both A and B |
| Choice E: | Both B and C |
| Choice F: | Both A and C |
| Question 3: Photon counting detectors offer the least advantage over energy-integrating detectors for the imaging task: |
| Reference: | Pourmorteza, A., Symons, R., Reich, D.S., Bagheri, M., Cork, T.E., Kappler, S., Ulzheimer, S. and Bluemke, D.A., 2017. Photon-counting CT of the brain: in vivo human results and image-quality assessment. American Journal of Neuroradiology, 38(12), pp.2257-2263. Willemink, M.J., Persson, M., Pourmorteza, A., Pelc, N.J. and Fleischmann, D., 2018. Photon-counting CT: technical principles and clinical prospects. Radiology, 289(2), pp.293-
312.Irradiation and Immunotherapy: From Concept to the Clinic, April K. S. Salama, MD; Michael A. Postow, MD; and Joseph K. Salama, MD Cancer, Vol 122, Issue 11, pp 1659-1671, 2016 |
| Choice A: | Differentiating calcified from fatty coronary plaques |
| Choice B: | Detection of bone edema |
| Choice C: | Detecting temporal bone erosion |
| Choice D: | Differentiating gray and white matter in the brain |
| Question 4: Compared to energy-integration detector, the uniform photon energy (spectral) weighting in PCDs results in: |
| Reference: | Gutjahr et al. Invest Radiol. 2016 Jul;51(7):421-9. |
| Choice A: | Improved image contrast-to-noise ratio |
| Choice B: | Reduced image artifacts |
| Choice C: | Improved spectral resolution |
| Choice D: | None of the above |
| Question 5: The absence of reflective interpixel septae in PCDs lead to: |
| Reference: | Leng et al. J Med Imaging. 2016 Oct; 3(4): 043504 |
| Choice A: | Increased geometric dose efficiency |
| Choice B: | Reduced charge sharing |
| Choice C: | Direct conversion of x-rays to electric signals |
| Choice D: | None of the above |
| Question 6: The conditioning of material decomposition in photon-counting CT is determined by: |
| Reference: | Tang X. and Ren Y. (2020) "On the conditioning of basis materials and its impact on multi-material decomposition based spectral imaging in photon-counting CT,” Medical Physics, 2021;48(3), 1100-1116.
Ren Y, Xie H, Long W, Yang X and Tang X (2020) "On the conditioning of spectral channelization (energy binning) and its impact on multi-material decomposition based spectral imaging in photon-counting CT,” IEEE Transactions on Biomedical Engi., 68(9), pp.2678-2688, 2021. |
| Choice A: | Correlation between the attenuation property of basis materials |
| Choice B: | Spectral overlapping between abutted spectral channels |
| Choice C: | Both a and b |
| Choice D: | None of the above |
