Diffusion-Weighted MRI in Creutzfeldt-Jakob Disease: Focus on the Cerebral Cortex and Chronologic Change

Purpose: To evaluate high cortical signal intensity and chronologic changes for diffusion-weighted MR imaging (DWI) in sporadic Creutzfeldt-Jakob disease. Materials and Methods: We retrospectively analyzed the DWI results of 16 patients with probable CJD (according to WHO criteria) and evaluated the distribution, extent and bilaterality of the lesions in the cortex, basal ganglia and thalamus. We also reviewed the chronologic changes of the lesions by evaluating the followup MR examination results in 8 of 16 patients. Results: Cortical abnormalities were present in 15 (94%) of 16 patients. Isolated cortical involvement was present in 6 patients (40%), while the combined involvement of the cortex and basal ganglia was present in 9 patients (60%). The distribution of the lesions was bilateral in 12 patients and predominantly on the right side in 8 patients. Upon follow-up MR imaging, the cortical lesions showed progress in terms of extent and signal intensity. Basal ganglia abnormalities were present in 9 of 15 patients. Moreover, 4 of 6 patients who had no abnormal signal intensity in the basal ganglia on the initial MR imaging results, showed abnormally high signal intensity upon follow-up MR imaging. Conclusion: The characteristically high cortical signal intensities on DWI in an elderly patient with rapidly progressive dementia should point to the diagnosis of early phase CJD and might be useful for the differential diagnosis.