Effect on spectral quantification of Back-Linear-Predicted and original first order dephased 1H-FID-MRSI data

Motivation: 1H Free-Induction Decay (FID) MRSI acquisition delay (AD) between the RF excitation pulse and the FID signal leads to loss of data. Backward Linear Prediction (BLP) approach has potential to recover this missing information. Goal(s): Evaluate the consistency of FID-MRSI spectral fitting after BLP to AD=0ms and possible bias of direct spectral quantification at AD≠0ms Approach: BLP was tested on full reconstruction of FID-MRSI signals from AD=1.3ms down to AD=0ms, on in vivo data and Monte Carlo simulations cut-and-recover approach Results: BLP showed good quantification consistency, while possible bias of quantification at AD≠0ms were found. Impact: The presented work revealed that with enough fitting baseline flexibility, FID-MRSI quantification at a theoretical reconstructed AD=0ms can achieve unbiased measurements, while it indicated that direct FID-MRSI quantification at AD≠0ms might generate systematic estimation offsets.