MRI PRACTICE QUESTIONS and answers 2023

MRI PRACTICE QUESTIONS and answers 2023What are two categories that diagnostic imaging contrast depends on? - correct answer Intrinsic and Extrinsic parameters Intrinsic parameters - correct answer -T1 recovery -T2 decay -PD -Flow These cannot be manipulated Extrinsic parameters - correct answer -TR -TE -FA -TI -b-value -echo train These can be manipulated by the MRT Factors that determine T1 and T2 relaxation times of tissue? - correct answer -the inherent energy of the tissue -how closely packed the molecules are -how well the molecules tumbling rate matches the lamor frequency Why does fat have short T1 and T2 relaxation times? - correct answer Hydrogen in fat recovers faster along longitudinal axis and loses transverse magnetization faster. Weighting - correct answer intrinsic parameters determine image contrast, producing mixed contrast signals, selecting a specific TR, TE value determines the weighting. MRI hardware - correct answer Magnet, RF source, image processor, computer system 3 types of magnetism - correct answer Diamagnetism, Paramagnetism, Ferromagnetism Ferromagnetism - correct answer shows strong attraction and alignment to external magnetic field. MRI magnets - correct answer Permanent magnet, Resistive magnet, Superconductive magnet What type of magnet can be switched off? - correct answer Resistive