Feasibility of Magnetic Resonance Fingerprinting on Aging MRI Hardware.

The purpose of this work is to evaluate the feasibility of performing magnetic resonance fingerprinting (MRF) on older and lower-performance MRI hardware as a means to bring advanced imaging to the aging MRI install base. Phantom and in vivo experiments were performed on a 1.5T Siemens Aera (installed 2015) and 1.5T Siemens Symphony (installed 2002). A 2D spiral MRF sequence for simultaneous T 1 /T 2 /M 0 mapping was implemented on both scanners with different gradient trajectories to accommodate system specifications. In phantom, for T 1 /T 2 values in a physiologically relevant range (T 1 : 195-1539 ms; T 2 : 20-267 ms), scanners had strong correlation (R 2 > 0.999) with average absolute percent difference of 8.1% and 10.1%, respectively. Comparison of the two trajectories on the newer scanner showed differences of 2.6% (T 1 ) and 10.9% (T 2 ), suggesting a partial explanation of the observed inter-scanner bias. Inter-scanner agreement was better when the same trajectory was used, with differences of 6.0% (T 1 ) and 4.0% (T 2 ). Intra-scanner coefficient of variation (CV) of T 1 and T 2 estimates in phantom were <2.0% and in vivo were ≤3.5%. In vivo inter-scanner white matter CV was 4.8% (T 1 ) and 5.1% (T 2 ). White matter measurements on the aging scanner after two months were consistent, with differences of 1.9% (T 1 ) and 3.9% (T 2 ). In conclusion, MRF is feasible on an aging MRI scanner and required only changes to the gradient trajectory.