Quality Control Flashcards
if the slice thickness is reduced by a factor of 2, the factor by which the NSA must be increased to maintain the same SNR is
4
if slice thickness is increased by a factor of 2 the SNR
increases by a factor of 2
if the slice thickness increases the SNR
increases
if the slice thickness increases the spatial resolution
decreases
changing the size of the voxel in the frequency directino will
have no effect on scan time
factors taht affect contrast include all of the following
TR
TE
TI
Flip angle
SNR is a factor that is measured
true
CNR is a factor that is measured
false
factors that affect spatial resolution include all of the following
FOV
slice thickness
matrix
factors that affect SNR include all of the following
TR
field strength
FOV
matrix
center frequency is a factor that determines the
freq of RF used for excitation
freq of RF used for signal detection
transmit gain is a factor that determines the
amplitude and or duration of the RF pulse (to determine fip angle)
geometric accuracy is determined by the
gradient system
during MR imaging all equimept should be inspected priot to use to be sure that components are in proper working order
components include
RF coils and cables
RF coils and door seals
cable and door seals
quench system
reducing the slice thickness by a factor of 2 will reduce the SNR by a factor of
2
