Toward Rapid Macromolecular Pool Size Mapping Via Selective Inversion Recovery

Richard D. Dortch¹, ², Ke Li¹, ², Daniel F. Gochberg¹, ², John C. Gore¹, ², Seth A. Smith¹, ²

The purpose of this study was to optimize the selective inversion recovery (SIR) quantitative magnetization transfer sequence for mapping of the macromolecular-to-free proton pool size ratio (PSR). Previous work has demonstrated that PSR is related to myelin content. Despite this promise, the time required for SIR imaging can be prohibitively long. Here, we reduce to total number of samples required for SIR imaging by fixing the rate of MT exchange and choosing a sampling strategy that minimizes the bias in PSR. Results indicate that unbiased, high SNR estimates of PSR can be obtained using this optimized approach.