ARRT MRI Mock Registry

ARRT MRI Mock Registry When imaging a geriatric patient, while performing a PCA MRA sequence, what imaging parameter might the operator adjust? A. Field of view B. Presaturation band location C. Slice thickness D. VENC E. Contrast injection rate - ANSWERVENC As the number of phase encodings is increased from 256 to 512, SNR (signal to noise ratio): A. Increases B. Decreases C. Doubles D. Does not change E. Quadruples - ANSWERDecreases A magnetic vector possesses attributes of both __________ and _____________. A. Strength; magnitude B. Direction; purpose C. Strength; flow D. Magnitude; direction - ANSWERMagnitude; direction What element in the body is the principal nucleus utilized in clinical MR imaging? A. Helium B. Hydrogen C. Oxygen D. Calcium - ANSWERHydrogen Which of the following best describes an IR sequence? A. A 180° pulse followed by a 90°/180° combination B. A 90° pulse followed by a 180° pulse C. A train of gradient echoes D. A train of spin echoes - ANSWERA 180° pulse followed by a 90°/180° combination Gradient echo sequences requiring high signal from fluid are known as all of the following EXCEPT: A. T2* gradient echo B. Steady -state gradient echo C. Coherent gradient echo D. Incoherent gradient echo - ANSWERIncoherent gradient echo The medial and lateral rectus muscles are located in the: A. Ears B. Posterior pelvic region C. Proximal calves D. Eyes E. Superior shoulder regions F. Soft tissues of the neck - ANSWEREyes Reducing the number of lines filled in k -space will produce an image: A. With a decrease in spatial resolution B. With a increase in spatial resolution C. With an decrease in overall SNR D. With an increase in overall SNR E. With a reduced overall scan time F. B, C and E only G. A, D and E only - ANSWERA, D and E only Reducing the number of lines filled in k -space reduces the number of phase encoding steps, resulting in shorter scan time, an increase in overall SNR, but a decrease in spatial resolution. The smallest object that can be resolved in an image acquired with a 24cm FOV and a 272 x 272 matrix is _________ mm. A. 0.76mm B. 0.88mm C. 0.93mm D. 1.13mm E. 1.24mm - ANSWER0.88mm To produce an image based on differences in T1, the time interval between 90° excitation pulses should be: A. Long B. Short C. Refocussed D. Inverted - ANSWERShort The energy used to form MRI images is ____________ the patient's tissues. A. Emitted from B. Attenuated by C. Amplified from D. Reflected off - ANSWEREmitted from Referencing the Centers for Disease Control and Prevention (CDC), what type of isolation precautions should be used for HIV -positive patients in the MRI suite? A. Respiratory B. Droplet C. Standard (universal) D. Enteric E. Contact - ANSWERStandard (universal) ___________ could be used to line the walls and/or floors of the MR magnet room to reduce the fringe field, and is defined as __________ shielding. A. Copper; active B. Steel; active C. Copper; passive D. Steel; passive E. Lead; active - ANSWERSteel; passive If the TR in a gradient echo sequence is less than the T2 (or T2*), the resulting condition is known as: A. Spin down B. Steady state C. Spin dephasement D. Thermal equilibrium - ANSWERSteady state Which type of blood cell is responsible for phagocytosis? A. Leukocyte B. Erythrocyte C. Lymphocyte D. Platelet - ANSWERLeukocyte Which of the following, in an MRA sequence, aids in minimizing the loss of signal due to dephasing within a voxel: A. Long TE B. Short TR C. Smaller voxel size