Intra- And Inter-Scanner Variability of Magnetization Transfer Ratio Using Balanced SSFP

Monika Gloor¹, Klaus Scheffler¹, Oliver Bieri¹

Magnetization transfer ratio (MTR) has become an important tool to study various tissue abnormalities, such as demyelination in brain white matter. Recently, a new technique for measuring MTR has been proposed based on balanced steady-state free precession (bSSFP) with modified radiofrequency pulses. The reproducibility and variability of MTR-bSSFP was analyzed on six healthy volunteers using two different 1.5T clinical systems. Intra-scanner MTR measurements were well reproducible (< 0.3 pu) and inter-scanner variation is below 0.5 pu for optimal flip angle settings ([pu]: percentage units). MTR-bSSFP benefits further from relatively low B₁ sensitivity, high signal-to-noise ratios, and short overall acquisition times.