MRSO: Exam mark with complete solutions 2023 passed!

MRSO: Exam mark with complete solutions 2023 passed!Which of the following describe when a non-ferrous object is repulsed by static magnetic field? a. Fourier transformation b. Lenz's force c. Ohm's law d. Larmor equation - correct answer b. Lenz's force What is the FDA SAR limit for the whole body in first level controlled operating mode? a. 8 W/kg for 15 mins b. 4 W/kg for 15 mins c. 3 W/kg for 10 mins d. 7 W/kg for 20 mins - correct answer b. 4 W/kg for 15 mins Gadolinium contains what kind of magnetism? a. Diamagnetic b. Paramagnetic c. Ferromagnetic d. Super paramagnetic - correct answer b. Paramagnetic Where will peripheral nerve stimulation be the strongest? a. Further away from isocenter in the gantry b. At the level of the table when it is advanced c. At isocenter d. Outside the gantry near the 5 gauss line - correct answer a. Further away from the isocenter in the gantry What is the name for the direction of the vector of the static magnetic field? a. Inverse field b. Equilibrium c. B0 d. B1 - correct answer c. B0 An object that produces a weakly repulsive force in the presence of a strong magnetic field is called what? a. Superparamagnetic b. Ferromagnetic c. Diamagnetic d. Paramagnetic - correct answer c. Diamagnetic The gradient coils are responsible for which of the following? Select all that apply. a. Heating b. Rotational force c. Translational force d. Magnetohydrodynamic effect e. Noise f. Peripheral nerve stimulation - correct answer e. Noise f. Peripheral nerve stimulation Why is magnetic shielding used in an MR unit? a. To reduce heating b. To reduce the e-fields c. To maintain field homogeneity d. To limit the fringe field - correct answer d. To limit the fringe field Contrast media will do what to our tissue? a. Shorten T1 relaxation times b. Shorten T1 & T2 relaxation times c. Increase T2 relaxation times and decrease T1 relaxation times d. Shorten T2 relaxation times - correct answer b. Shorten T1 & T2 relaxation times As blood flows through a vessel, currents can be induced. The degree of this is called? a. Magnetophosphenes b. Flow potential c. Translational forces d. Fringe field - correct answer b. Flow potential The T-wave in the cardiac cycle represents what? a. Heart repolarization b. Heart depolarization c. None of the choices d. Arrhythmia - correct answer a. Heart repolarization NSF is caused by what? a. When the patient is allergic to gad contrast b. When gad ion is excreted by the liver c. When gad ion is excreted from the body quickly d. When a gad ion breaks free from the ligand and remains in the body - correct answer d. When a gad ion breaks free from the ligand and remains in the body