| Question 1: How is high resolution reflection mode achieved with the low, <2 MHz frequency main transducers in coherent ultrasound tomography systems? |
| Reference: | R.S.C. Cobbold, Foundations of Medical Ultrasound. 2007: Oxford Univ. Press, pp. 550 ff.
2 S.J. Norton and M. Linzer, "Ultrasonic Reflectivity Tomography: Reconstruction with Circular Transducer Arrays," Ultrason. Imaging 1(2), 154-184, (1979).
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| Choice A: | Harmonic imaging is employed to double the effective frequency. |
| Choice B: | The full, 360º aperture of the transducer elements allows focusing to 0.6 times the center wavelength c of a broadband pulse. |
| Choice C: | Advanced image processing sharpens the image with little effect on the low contrast detectability. |
| Question 2: How can US transmission tomography produce quantitative speed of sound images? |
| Reference: | R.S.C. Cobbold, Foundations of Medical Ultrasound. 2007: Oxford Univ. Press, pp. 550 ff. |
| Choice A: | The same as x-ray CT, the arrival time of a pulse is the line integral of the log of the speed of sound along the ray path between two transceiver elements. |
| Choice B: | Nearly the same as x-ray CT, the arrival time of a pulse is the line integral of the log of the reciprocal of the speed of sound along the ray path between two transceiver elements. |
| Choice C: | Nearly the same as x-ray CT, the arrival time of a pulse is the line integral of the log of the reciprocal of the speed of sound along the ray path between two transceiver elements except the sound does not travel in exactly straight lines. |
| Question 3: What are the effects of performing limited angle ultrasound transmission tomography as opposed to full, 360º aperture imaging? |
| Reference: | R.S.C. Cobbold, Foundations of Medical Ultrasound. 2007: Oxford Univ. Press, pp. 550 ff. |
| Choice A: | The same as x-ray tomosynthesis vs CT; resolution in the direction of the central rays (axial direction) is compromised due to lack of rays passing in the lateral direction. |
| Choice B: | The same as x-ray tomosynthesis vs CT; resolution in lateral and slice thickness directions are improved due to higher resolution rays that may be used with the shorter path lengths of limited angle views in noncylindrical/nonspherical tissue geometries. |
| Choice C: | The same as x-ray tomosynthesis vs CT; the images are nonquantitative with the ill-posed reconstructions, unless a priori information is available on the tissue structures and properties. |
| Choice D: | All of the above. |
| Question 4: Which of these makes it easier for US transmission tomography to produce attenuation coefficient images of high fidelity? |
| Reference: | R.S.C. Cobbold, Foundations of Medical Ultrasound. 2007: Oxford Univ. Press, pp. 550 ff. |
| Choice A: | Very broadband pulses much be used, with frequencies having widely different attenuation coefficients. |
| Choice B: | In-plane and out-of-plane diffraction loses from the expected wave pattern, including total reflection at grazing incidence to boundaries, make the received signal less than expected from absorption and local scattering in a tissue structure. |
| Choice C: | A and B. |
| Question 5: The reason for using two ultrasound beams in vibro-acoustography is: |
| Reference: | Urban MW, Alizad A, Aquino W, Greenleaf JF, Fatemi M. A Review of Vibro-acoustography and its Applications in Medicine. Curr Med Imaging Rev. 2011 Nov 1;7(4):350-359. |
| Choice A: | To produce a force at the difference frequency. |
| Choice B: | To speed up the scanning. |
| Choice C: | To reduce the heat generated by ultrasound. |
| Choice D: | None of the above. |
| Question 6: What is “sum of the angles” parameter? |
| Reference: | Sarah E. Shelton, Yueh Z. Lee, Mike Lee, Emmanuel Cherin, F. Stuart Foster, Stephn R. Aylward, Paul A. Dayton. Quantification of microvascular tortuosity during tumor evolution utilizing acoustic angiography. Ultrasound Med Biol. 41(7), July 2015, Pages 1896-1904. |
| Choice A: | A measure of vessel tortuosity. |
| Choice B: | A measure of blood flow turbulence. |
| Choice C: | The number of angles in sector imaging. |
| Choice D: | None of the above. |
| Question 7: Which answer is NOT true about tissue motion and blood activity? |
| Reference: | Demené C, Deffieux T, Pernot M, Osmanski BF, Biran V, Gennisson JL, Sieu LA, Bergel A, Franqui S, Correas JM, Cohen I, Baud O, Tanter M. Spatiotemporal Clutter Filtering of Ultrafast Ultrasound Data Highly Increases Doppler and fUltrasound Sensitivity. IEEE Trans Med Imaging 2015 Nov;34(11):2271-85. doi: 10.1109/TMI.2015.2428634. Epub 2015 Apr 30. |
| Choice A: | Tissue motion results in spatial shift of speckle patterns. |
| Choice B: | Blood cell activity results in changes in speckle pattern. |
| Choice C: | Blood cell motion results in rapid temporal fluctuation of the signal. |
| Choice D: | Tissue motion has lower spatial coherence than blood signal. |
| Question 8: The use of ultrasound guidance for biopsies of suspicious microcalcification clusters is never recommended: |
| Reference: | American College of Radiology. ACR practice parameter for the performance of ultrasound-guided percutaneous breast interventional procedures. Available at:
https://www.acr.org/-/media/ACR/Files/Practice-Parameters/US-GuidedBreast.pdf
Accessed April 21, 2018.
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| Choice A: | True. |
| Choice B: | False. |
| Question 9: The time needed to perform a biopsy is significantly shorter with digital breast tomosynthesis-guided vacuum-assisted biopsy (DBT-VAB) than prone-stereotactic guided vacuum-assisted biopsy (PS-VAB) because: |
| Reference: | S. Schrading, et al. Digital Breast Tomosynthesis–guided Vacuum-assisted Breast Biopsy: Initial Experiences and Comparison with Prone Stereotactic Vacuum-assisted Biopsy. Radiology 2015 274:3, 654-662 |
| Choice A: | Patients are less comfortable on the DBT-guided table, causing the radiologist to speed up the procedure. |
| Choice B: | Lesion re-identification is easier with DBT-VAB than PS-VAB. |
| Choice C: | Manual positioning of the x-ray source during stereo acquisition slows the procedure. |
| Question 10: The advantages of image-guided core-needle biopsy over surgical biopsy include: |
| Reference: | American College of Radiology. ACR practice parameter for the performance of ultrasound-guided percutaneous breast interventional procedures. Available at:
https://www.acr.org/-/media/ACR/Files/Practice-Parameters/US-GuidedBreast.pdf
Accessed April 21, 2018.
W. Bruening et al. Systematic review: comparative effectiveness of core-needle and open surgical biopsy to diagnose breast lesions. Ann Intern Med. 2010;152(4):238-246.
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| Choice A: | Fewer complications. |
| Choice B: | Greater cost-effectiveness. |
| Choice C: | Comparable accuracy in diagnosing cancer. |
| Choice D: | All of the above. |
