Strong Regularization for Brain Myelin Water Quantification in T2 Relaxation MRI Obtained in 3.0T

Qing Ji¹, Junyu Guo¹, John O. Glass¹, Wilburn E. Reddick¹

Quantification of myelin water fraction (MWF) involves the calculation of the T2 distributions of relaxation spectra using a regularized non-negative least square (NNLS) algorithm. Simulated and experimental T2 decay data were used to investigate the influence of the NNLS regularization on the MWF calculation. The relationship between the MWF and regularization is a V shape curve. The regularization which gave the most accurate and stable agreement with the simulated data was on the strong side of the curve in contrast to previous studies which suggested a weak regularization. Use of the stronger regularization was demonstrated for in vivo data.