Investigating the Accuracy of PD Measurements at 3T

We investigated the accuracy of clinical proton density (PD) mapping employing the variable flip-angle (VFA) method at 3T, considering the effects of B1+ and B1- fields. Following B1+ correction, the PD measurements were within 5% of the expected value for flip-angle variations up to 18%. Considerable discrepancies were observed for T1<300ms and flip-angle variations >25%. Using image intensity filters, considerable PD variations were found at the edges of the test object. Clinically, the B1+ and B1- corrected PD values of the brain were similar to values reported in the literature, rendering the VFA method a viable tool for PD mapping.