How Reliable Are Current Practices in Reconstructing Relaxation Spectra for Detecting the T2 Myelin Water Signal When Applied to Real in Vivo T2 Decays?

Keith S. Cover¹

The results of this study demonstrated that, for in vivo T2 decays of white matter measured using current practices, bias in both Whittall’s and Mackay’s nonnegative least squares and fitting a few monoexponentials reconstruction algorithms can yield highly reproducible but false positive detections of the T2 myelin water signal. In contrast, data conserving reconstruction matrices (DCRM) yielded highly reliable results but required several times the signal to noise ratio (SNR). More in vivo measurements of a variety of structures and pathologies at high SNR are required to determine the most useful trade off between reliability of the reconstruction algorithm and the SNR.