MRI PULSE SEQUENCES- ARRT REVIEW TEST 2023.

MRI PULSE SEQUENCES- ARRT REVIEW TEST 2023. pulse sequence - ANSWER A ___________________ is a set of specifically timed instructions to the magnet telling it how images should look with regards to the tissue being sampled. gradient echo sequence; 180 refocusing RF pulse - ANSWER The ________________ lacks a ____________________, making it more susceptible to magnetic field inhomogeneities. gradient pulse sequence - ANSWER refocus - ANSWER In a gradient echo pulse sequence, the gradient coils are used to ____________ the protons and create the echo. gradient field; RF pulse - ANSWER In order to produce an echo in a gradient echo pulse sequence, a ____________and an __________are used. T1 or T2*; susceptiblity; chemical shift; inhomogeneities - ANSWER Gradient echo sequences can yield either __________ characteristics, with influences caused by ________, ____________, and ____________. steady state; residual transverse magnetization - ANSWER The condition of _____________occurs when the TR in a gradient echo is less than the T2 (or T2*), resulting in _____________________ at the time of the next excitation pulse. T2* Gradient Echo; steady state gradient echo; coherent gradient echo - ANSWER Gradient echo sequences requiring high signal from fluid are known as ____________,___________, and ______________. incoherent gradient echo; T1 - ANSWER ___________________ (or spoiled gradient echo) sequences yield ______ contrast due to the removal of residual transverse magnetization before the next excitation. BTFE - ANSWER __________sequences are variations of high T2 signal, balanced steady state sequences. Also known as TrueFISP, BASG, True SSFP, and Fiesta T2/T1, cranial nerves - ANSWER BTFE sequences are equipped with slice, phase and frequency rewinder pulses, yielding images with mixed contrast ____________, showing an image of high SNR and useful for evaluation of _________________. spoiled gradient echo sequence - ANSWER A ________________________ removes any residual transverse magnetization prior to the next excitation pulse