FIG. 1.

Illustration of the four conventional MR images from a single section in one patient, the resulting segmentation map, and the quantitative T₁ map. The four MR images, from left to right, are T₁-, T₂-, PD-, and FLAIR-weighted. The sensitivity of the FLAIR imaging sequence is demonstrated. The resulting pseudocolor segmentation map is used for volumetric analyses and to mask tissues for subsequent analysis of relaxation time. Masks of orange identify regions of leukoencephalopathy and masks of green identify regions of normal-appearing white matter. Yellow areas indicate gray matter and blue areas indicate cerebrospinal fluid. In the corresponding quantitative T₁ relaxation map (far right), the signal intensity of each pixel represents the relaxation rate calculated at that position.