PT2 Chapter 1 & 2: Introduction and History | RF Pulse Sequences Spine Echo based Quiz Please purchase the course before taking this quiz. which is true? To optimize the contrast between the WM and GM in the brain the flip angle should be reduced due to the field strength and TE To optimize the contrast between the WM and GM in the brain the flip angle should be reduced due to the field strength and TR . Hahn echoes were discovered by Carr and Purcell True False which is true? . T2* contrast can be achieved in SE RF sequences because it is a time-constant showing the spin-spin interactions. The FID signal is caused by an RF pulse In a SE RF sequence with 2 echoes resp. 30- and 120ms the 180 RF pulses are on 30 and 60ms True False The transverse relaxation time T2 is shorter as the protons are stronger coupled with each other in a tissue True False . The magnetization vector spreads out in the x-y plane after the 180° RF pulse True False After excitation of an RF pulse <180° the tissue magnetization is a rotating movement with a certain angle around the external field direction (precession motion) True False which are true? T1w contrast in SE RF sequences can be accomplished by short TR and short TE PDw contrast in SE RF sequences can be accomplished by short TR and long TE The TR influences the S/N Ratio in a SE RF sequence technique True False . The GM has a higher T1 value than the WM brain tissue True False
