Section Editor: Sandy Cheng-Yu Chen, M.D.
Taipei Medical University Hospital, Taipei, Taiwan
Figure Caption
Canavan disease, also known as spongiform leukodystrophy, is an autosomal recessive disorder characterized by accumulation of N-acetyl aspartic acid (NAA) in urine, brain, and plasma causing vacuolation of the subcortical U-fibers extending inwards to involve the deep white matter. The classic MR imaging findings are diffuse T2 hyperintensity of white matter that involves the subcortical U-fibers (arrows in A and B) early in the course of disease, with sparing of bilateral basal ganglia (B). On proton MR spectroscopy, an elevated NAA level at 2.06 ppm (arrow in C) may help establish the diagnosis.