Comparison of diffusion-weighted MRI with 18F-fluorodeoxyglucose-positron emission tomography/CT and electroencephalography in sporadic Creutzfeldt-Jakob disease.

18F-fluorodeoxyglucose-positron emission tomography/CT (18F-FDG PET/CT) scanning may be a useful tool for early diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD), as it may reveal lowered cellular glucose transport and metabolism in the cortex, cerebellum and basal ganglia. The aim of the present study was to compare the findings from PET/CT, MRI and electroencephalography (EEG) for patients with sCJD, to explore whether typical sites or reliable patterns of regional metabolic change could be found and to evaluate the results of diagnostic imaging in the light of clinical symptomatology. Five patients with biopsy-confirmed sCJD and nine with probable sCJD (aged 36-68 years) were evaluated using PET/CT, diffusion-weighted (DW)-MRI and EEG. In 13 of the 14 patients (92.86%), PET/CT imaging detected extra regions with abnormalities in addition to the hyperintense areas shown with DW-MRI. Two patients with no abnormal DW-MRI findings in the basal ganglia had bilateral extrapyramidal signs accompanied by basal ganglia hypometabolism on PET. Eight patients (57.14%) had decreased FDG uptake in the thalamic nuclei on PET scans; however, DW-MRI did not identify corresponding hyperintense changes in the thalamic nuclei. In 11 patients (78.57%), DW-MRI revealed more regions with abnormalities than EEG, and 10 patients (71.43%) had DW-MRI abnormalities in the thalamic nuclei and basal ganglia that EEG was unable to detect. There was a high level of correspondence among the PET/CT, DW-MRI and EEG results, with PET revealing more abnormal regions than the other imaging modalities. In the absence of neuropathological findings, FDG-PET could improve the accuracy of sCJD diagnosis when combined with DW-MRI and EEG, particularly for differentiating sCJD from paraneoplastic syndromes. Our results suggest that PET/CT is able to detect sCJD at an earlier stage and with greater sensitivity than DW-MRI.