Emerging patterns of diffusion, perfusion-weighted MRI and spectroscopy in creutzfeldt-jacob disease.

Sporadic Creutzfeldt-Jacob disease (CJD) is a transmissible, progressive, fatal spongiform encephalopathy. Routine MR imaging sequences may show abnormalities in the basal ganglia and cerebral cortex. Recently, several reports claimed that diffusion weighted MRI (DWI) could demonstrate early brain lesions in CJD patients when conventional MR images are normal on T2-weighted sequences. We evaluated the usefulness of DWI, perfusion-weighted MRI (PWI) and spectroscopy to confirm the clinical diagnosis and assess lesion progression in two patients with suspected CJD. We noted a diffuse hypoperfusion in the basal ganglia where ADC values were reduced but spectroscopy values were normal. A strong hypoperfusion was observed in the right head of the caudate nucleus in patient n° 2 where spectroscopy values were abnormal. A typical distribution of hypoperfusion followed the posterior progression of disease. We suggest the hypoperfusion in the areas presenting restricted diffusion probably reflects spongiform degeneration and moderate mass effects from cytotoxic edema.