2016 AAPM Annual Meeting
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Session Title: MRI Physics
Question 1: For each million protons in 3.0T field, what approximately is the excess number of protons with spins aligned with the field versus those aligned against it?
Reference:Magnetic Resonance Imaging, R.W. Brown et al., 2nd Edition 2014, pp 4-5
Choice A:One million.
Choice B:Zero.
Choice C:Ten.
Choice D:Three.
Question 2: On a T1-weighted MR image, tissues with long spin lattice relaxation...
Reference:MRI. From Picture to Proton, D.W. McRobbie et al., 2nd Edition, 2007, p. 33
Choice A:Appear bright.
Choice B:Appear dark.
Choice C:Have same signal intensity as tissues with short spin lattice relaxation.
Choice D:Impossible to say.
Question 3: Which method is NOT in the list for assessment of magnetic field homogeneity recommended by the ACR?
Reference:2015 MRI Quality Control Manual, ACR, p.74
Choice A:Spectral peak method.
Choice B:Bandwidth-difference method.
Choice C:Frequency map method.
Choice D:Phase-map method.
Choice E:Phase-difference method.
Question 4: What is the recommended action criterion for percent integral uniformity on ACR phantom using volume coils at 3.0 T field strength?
Reference:Phantom Test Guidance for the ACR MRI Accreditation Program,2005, p.17
Choice A:Greater than 87.5%
Choice B:Greater than 82.0%
Choice C:Lesser than 82.0%
Choice D:Greater than 80.0%
Question 5: In echo planar imaging (EPI), chemical shift, a difference in the resonance frequency such as the difference between fat and water, will cause a miss-registration in:
Reference:Jerrold T. Bushberg, et al, The Essential Physics of Medical Imaging, Second Edition. Lippincott Williams and Wkilkins 2002. p. 453
Choice A:Slice selection direction.
Choice B:Frequency encoding direction.
Choice C:Phase encoding direction.
Choice D:All directions.
Question 6: During image reconstruction, a low pass filter is typical applied to the raw data in K-Space. The main purpose of such filter is to:
Reference:Jerrold T. Bushberg, et al. The Essential Physics of Medical Imaging, Second Edition. Lippincott Williams and Wkilkins 2002. p. 455
Choice A:Reduce motion artifact.
Choice B:Improve image resolution.
Choice C:Reduce ringing artifact.
Choice D:Improve image contract.
Question 7: When a K-Space low pass filter is applied as in question 2, what would be its impact to the SNR:
Reference:Jerrold T. Bushberg, et al. The Essential Physics of Medical Imaging, Second Edition. Lippincott Williams and Wkilkins 2002. p. 442
Choice A:Increase.
Choice B:No change.
Choice C:Decrease.
Choice D:Becomes non-uniform.
Question 8: An inversion recovery pulse sequence uses which combination of RF pulses:
Reference:The Essential Physics of Medical Imaging, JT Bushberg, JA Seibert, EM Leidholdt Jr, JM Boone, 3rd edition, 2012, p. 421-437.
Choice A:90 degree, 180 degree,
Choice B:90 degree, 180 degree, 180 degree
Choice C:180 degree, 90 degree, 180 degree
Choice D:One RF pulse less than 90 degrees
Question 9: In 2D spin echo imaging, the slice select gradient is applied at the same time as the...
Reference:Handbook of MRI Pulse Sequences, MA Bernstein, KF King, XJ Zhou, 2004, p.632-634.
Choice A:Spin echo.
Choice B:Frequency encode gradient.
Choice C:Phase encode gradient.
Choice D:Radio frequency pulses.
Question 10: Echo planar imaging produces images characterized by....
Reference:The Essential Physics of Medical Imaging, JT Bushberg, JA Seibert, EM Leidholdt Jr, JM Boone, 3rd edition, 2012, p. 456.
Choice A:Low resolution, decreased artifacts
Choice B:Low resolution, increased artifacts
Choice C:High resolution, decreased artifacts.
Choice D:High resolution, increased artifacts
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