Question 1: How does the dynamic range in CT signal differ between relative electron density and atomic number at typical CT X-ray energies for bone and contrast agents? Is it:
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Reference: | Landry et al, Phys. Med. Biol. 2013, Vol 58(19). Deriving effective atomic numbers from DECT based on a parameterization of the ratio of high and low linear attenuation coefficients - http://dx.doi.org/10.1088/0031-9155/58/19/6851
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Choice A: | Larger. |
Choice B: | Smaller. |
Choice C: | Not Significant. |
Choice D: | Material dependent. |
Question 2: Phantom studies comparing estimated accuracy with proton, DECT and SECT found that:
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Reference: | Yang M, Virshup G, Clayton J, Zhu XR, Mohan R Dong L. Theoretical variance analysis of single- and dual- energy computed tomography methods for calculating proton stopping power ratios of biological tissues. Phys Med Biol 2010; 55: 1343-1362.
-Hansen C et al, Acta Oncologica 2015, Vol 59(9). A simulation study on proton computed tomography (CT) stopping power accuracy using dual energy CT scans as benchmark. DOI: 10.3109/0284186X.2015.1061212
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Choice A: | Calculations of electron density and effective atomic number are lower for DECT than for SECT . |
Choice B: | Proton CT gave slightly better stopping power estimates than DECT. |
Choice C: | Stopping power estimates were worse using SECT than DECT. |
Choice D: | All of the above. |
Question 3: Which of the following statements is correct regarding monoenergetic image reconstruction of dual-energy CT data?
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Reference: | 1. Marin D. State of the art: dual-energy CT of the abdomen. Radiology 2014; 271(2):327-42.
2. Mileto A et al. Impact of dual-energy multi-detector row CT with virtual monochromatic imaging on renal cyst pseudoenhancement: in vitro and in vivo study. Radiology 2014; 272 (3):767-76 |
Choice A: | Are used to generate an iodine map. |
Choice B: | Are generated subtracting iodine from a post-contrast data-set. |
Choice C: | Low kV data-sets improve the detection of iodine uptake. |
Choice D: | Low kV data-sets reduce the detection of iodine uptake. |
Choice E: | High kV data-sets improve the detection of iodine uptake. |
Question 4: Which of the following statements is correct regarding virtual unenhanced images derived from dual-energy CT? |
Reference: | De Cecco CN, et al. Virtual Unenhanced Images of the Abdomen with Second Generation Dual-Source Dual-Energy Computed Tomography: Image Quality and Liver Lesion Detection. Invest Radiol 2013;48(1):1-9. |
Choice A: | Are useful to quantify iodine uptake. |
Choice B: | Are generated subtracting iodine from a post-contrast data-set. |
Choice C: | Are used to generate different kV data-sets. |
Choice D: | Can be generated only from an arterial phase data-set. |
Choice E: | Improve the detection of iodine uptake. |
Question 5: What of the following is not a technique for obtaining different x-ray spectra for the energy measurements: |
Reference: | Reference: Computed Tomography: Principles, Design, Artifacts, and Recent Advances, Hsieh J, 3rd edition, SPIE Press, 2015.
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Choice A: | Different kVp |
Choice B: | Different filtration |
Choice C: | Different reconstruction kernel |
Choice D: | Energy discriminating detector |
Question 6: The principal advantage of raw data (or sinogram) domain spectral processing versus image domain spectral processing is:
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Reference: | Computed Tomography: Principles, Design, Artifacts, and Recent Advances, Hsieh J, 3rd edition, SPIE Press, 2015. |
Choice A: | Registration of the raw data is not required. |
Choice B: | Accurate beam hardening can be included. |
Choice C: | It is simpler to implement. |
Choice D: | All of the above. |