NICHD MRI grade reflects both the degree and gross distribution of brain injury on conventional MRI. Grades include categories for normal MRI (0), cortical/subcortical involvement only (1A (minimal cerebral lesions) and 1B (more extensive cerebral lesions), basal ganglia/thalamic/deep white matter involvement only (2A (basal ganglia, thalamic, internal capsule lesions only), or involvement of both areas (2B (basal ganglia, thalamic, internal capsule, and cerebral lesions) and 3 (cerebral devastation)). T-scores are normed against typical validation groups with mean scores of 50 (higher dotted line) and a standard deviation of 10; a T-score of 20 represents the floor of the instrument for individual subscores (lower dotted line).