What is the specific flip angles used in gradient echo sequences
they can be variable starting 0-180 degree
what are the typical values in gradient echo with a long tr and short tr
long: 100ms+
short tr: less than 50 ms
what are the values of a low flip angle range
between 5-20degress
what are the large flip angles used in gradient sequences
70+ degree
in order to obtain a t1 weighted image in gradient sequence yo need what te? tr? flip?
short tr
short te
and large flip angle
How do you produce a t2 weighted image
Long tr and te
small flip angle
How do you produce a pd image
long tr short te
small flip angle
Using a long TE enhances T2 and T2* contrast.
t or F
True because Long TEs always give the spins more time to dephase before the echo is read, therefore increasing T2 contrast. This is true in spin echo and gradient echo sequences.
Combining a low flip and long TR results in saturation.
true or false
False. This combination results in the vectors being flipped through a small angle while giving them a long time to recover using a long TR. Hence the vectors never exist beyond the transverse plane in saturation.