Single-Voxel Proton Magnetic Resonance Spectroscopy Findings at 3 Tesla in a Dog With Gliomatosis Cerebri

Gliomatosis cerebri (GC) represents an antemortem diagnostic challenge in the absence of histopathology. Proton magnetic resonance spectroscopy (1H-MRS) features of the disease in humans include elevated myo-inositol (mI)-to-creatine and decreased N-acetyl-aspartate (NAA)-to-creatine ratios. Brain 1H-MRS findings at 3 Tesla (3 T) field strength in dogs with GC have not yet been described. A 12-year-old West Highland White Terrier was presented with a progressive history of multifocal encephalopathy. A 3 T MRI revealed a diffuse, bilateral, ill-defined, intra-axial white matter lesion that was T2W and FLAIR hyperintense, T1W iso- to hypointense, showed no contrast enhancement, and was associated with moderate mass effect. 1H-MRS with voxel positioning at the left parietal area showed highly elevated mI and decreased NAA levels compared to healthy control dogs measured using the same protocol in the thalamus. GC was confirmed by stereotactic brain biopsy. Comparable 1H-MRS changes to those reported in humans were identified in a dog with GC.