An interleaved sequence for accurate and reproducible clinical measurement of magnetization transfer ratio.

We demonstrate an interleaved dual spin echo-based sequence for quantitative measurement of Magnetisation Transfer Ratio (MTR) in a clinical environment that overcomes the problems of patient motion between scans faced by noninterleaved methods. The sequence also provides proton density and T2-weighted images, allowing direct comparison among the three contrast regimes. Phantom studies and in vivo measurements on normal controls show the sequence to be robust in normal use. The values of MTR calculated from the sequence are shown to be precise and reproducible enough to allow regional variations to be identified within and between white matter and other brain tissues.