| Question 1: Which type of dual-energy CT does not provide tube current modulation in dual-energy CT imaging mode currently? |
| Reference: | McCollough et al, Principles and applications of multienergy CT: Report of AAPM Task Group291, Med Phys 47(7), 2020 |
| Choice A: | Dual-layer detector dual-energy CT |
| Choice B: | Split-Beam dual-energy CT |
| Choice C: | Dual-source dual-energy CT |
| Choice D: | Fast-kV switching dual-energy CT |
| Question 2: Which type of dual-energy CT has reduced field of view in dual-energy CT imaging compared to conventional imaging? |
| Reference: | McCollough et al, Principles and applications of multienergy CT: Report of AAPM Task Group291, Med Phys 47(7), 2020 |
| Choice A: | Dual-layer detector dual-energy CT |
| Choice B: | Split-Beam dual-energy CT |
| Choice C: | Dual-source dual-energy CT |
| Choice D: | Fast-kV switching dual-energy CT |
| Question 3: Which type of dual-energy CT can only perform image-space decomposition, rather than projection-space decomposition? |
| Reference: | McCollough et al, Principles and applications of multienergy CT: Report of AAPM Task Group291, Med Phys 47(7), 2020 |
| Choice A: | Dual-source dual-energy CT |
| Choice B: | Dual-layer detector dual-energy CT |
| Choice C: | Photon-counting CT |
| Choice D: | Fast-kV switching dual-energy CT |
| Question 4: On a dual-source DECT system, which is the most common method used to generate a simulated conventional CT image set? |
| Reference: | Albrecht MH, Vogl TJ, Martin SS, Nance JW, Duguay TM, Wichmann JL, De Cecco CN, Varga-Szemes A, van Assen M, Tesche C, Schoepf UJ. Review of Clinical Applications for Virtual Monoenergetic Dual-Energy CT. Radiology. 2019;293(2):260-271. |
| Choice A: | Using a 120 keV monoenergetic image |
| Choice B: | Calculating a weighted average between the low- and high-energy spectra |
| Choice C: | Using a 70 keV monoenergetic image |
| Choice D: | Reconstructing data from the low-energy tube |
| Choice E: | None of the above |
| Question 5: Calcium appears _______ on iodine-specific images and ________ on iodine-removed images, respectively |
| Reference: | Parakh A, Lennartz S, An C, Rajiah P, Yeh BM, Simeone FJ, Sahani DV, Kambadakone AR. Dual-Energy CT Images: Pearls and Pitfalls. Radiographics. 2021;41:98-119 |
| Choice A: | Hyperintense, hyperintense |
| Choice B: | Hyperintense, isointense |
| Choice C: | Hypointense, hyperintense |
| Choice D: | Isointense, hyperintense |
| Choice E: | Hypointense, isointense |
| Question 6: Virtual monoenergetic images can be calculated by: |
| Reference: | McCollough CH, Boedeker K, Cody D, Duan X, Flohr T, Halliburton SS, Hsieh J, Layman RR, Pelc NJ. Principles and Applications of Multienergy CT: Report of AAPM Task Group 291. Medical Physics. 2020:47(7):881-912. |
| Choice A: | Determining material densities for iodine and water |
| Choice B: | Estimating the photoelectric and Compton effect contributions |
| Choice C: | Performing a weighted average of the low- and high-energy images |
| Choice D: | a & c |
| Choice E: | All of the above |
| Question 7: Which DECT image below could be used to reduce metal artifact? |
| Reference: | Albrecht MH, Vogl TJ, Martin SS, Nance JW, Duguay TM, Wichmann JL, De Cecco CN, Varga-Szemes A, van Assen M, Tesche C, Schoepf UJ. Review of Clinical Applications for Virtual Monoenergetic Dual-Energy CT. Radiology. 2019;293(2):260-271. |
| Choice A: | Virtual non-contrast |
| Choice B: | 40 keV monoenergetic image |
| Choice C: | Virtual non-calcium |
| Choice D: | 120 keV monoenergetic image |
| Choice E: | 70 keV monoenergetic image |
| Question 8: Which of the following statements regarding the use of DECT for the assessment of intra-cranial hemorrhages is true? |
| Reference: | Potter C, Sodickson A. Dual Energy CT in Emergency Neuroimaging: Added Value and Novel Applications. RadioGraphics 2016;36:2186-2198 |
| Choice A: | The DECT images have always a better signal to noise ratio compared to conventional CT |
| Choice B: | The differentiation between the grey and white matter of the brain improves with increasing virtual monochromatic KeV |
| Choice C: | DECT is not sensitive to metal artifacts from vascular clips or other metal foreign bodies like bullet fragments |
| Choice D: | DECT can be used to remove the skull bones from a CT image to improve the display of hemorrhage in the subdural space |
| Choice E: | None of the above |
| Question 9: Which of the following is true about the differentiation between iodine based iv contrast and intra-cranial hemorrhage? |
| Reference: | Potter C, Sodickson A. Dual Energy CT in Emergency Neuroimaging: Added Value and Novel Applications. RadioGraphics 2016;36:2186-2198 |
| Choice A: | IV contrast and hemorrhages are always displayed with different attenuations |
| Choice B: | IV contrast is displayed with increasing attenuation in higher KeV virtual monochromatic images |
| Choice C: | DECT imaging of intracranial structures always requires pre-and post-contrast scans to differentiate between hemorrhage and the contrast material |
| Choice D: | Useful virtual non-contrast images cannot be generated from DECT of the head due to the beam hardening caused by the skull |
| Choice E: | DECT enables the detection of IV contrast uptake even in large intra-cranial hematoma |
| Question 10: Bowel injuries occur regularly in trauma and are a significant source of complication. Which are the advantages of DECT compared to conventional CT detecting these injuries: |
| Reference: | Wortman J, Uyeda J, Fulwadhva U, Sodickson A. Dual-Energy CT for Abdominal and Pelvic Trauma. RadioGraphics 2018; 38:586–602 |
| Choice A: | DECT does not require the use of IV contrast enhancement to detect bowel injury |
| Choice B: | High KeV (>150KeV) virtual monochromatic images are best to detect decreased contrast uptake and – perfusion in injured bowel loops |
| Choice C: | DECT derived iodine map overlays are useful to differentiate between normal contrast enhancing and injured bowel loops. |
| Choice D: | Iodine containing oral contrast media are mandatory to detect small bowel injuries with DECT |
| Choice E: | None of the above |
