The sensitivity of low flip angle RARE imaging

It is demonstrated that the stability of the Carr-Purcell-Meiboom-Gill (CPMG) sequence reflects the existence of a steady state solution to the Bloch equations in the absence of T2 and T1 decay. The steady state theory is then used to evaluate the performance of low flip angle RARE imaging sequences with both constant and optimally varied refocusing flip angles. The theory is experimentally verified in phantoms and then optimized, single shot, low flip angle RARE is used to obtain artifact-free images from the brain of a normal volunteer.