Usefulness of high b-value diffusion-weighted MRI in the diagnosis of Creutzfeldt-Jakob disease

Abstract

Background: current diagnostic criteria of probable Creutzfeldt-Jakob disease (CJD) include a combination of clinical, EEG and analytic data. Recent data indicate that brain MRI including fluid-attenuated inversion recovery (FLAIR) and diffusion-weighted imaging (DWI) sequences can be a valid and reliable tool for the diagnosis of CJD. We describe our experience with high b-value (3000s/mm(2)) diffusion-weighted imaging (DWI) in patients with probable or definite CJD and compare it with standard b-value (1000s/mm(2)) DWI.

Methods: we performed a retrospective analysis of patients admitted to our Hospital Service between 2002 and 2008 with a final diagnosis of probable or definite CJD. Patients were examined using either a 1.5 Tesla or a 3 Tesla MRI. The MRI protocol included T1-weigthed spin-echo sequences, T2-weighted fast spin-echo, FLAIR and DWI sequences with high b-value and standard b-value.

Results: during the study period there were 7 patients with probable or definite CJD. Only 3 patients (43%) showed changes on FLAIR sequence consistent with CJD. All the cases were detected with high b-value DWI, including 2 cases (28%) that would have been missed using standard b-value (1000s/mm(2)) DWI. In all the patients the changes were more conspicuous and extensive at high b-value DWI (b=3000s/mm(2)).

Conclusion: our data indicate that high b-value DWI may improve the sensitivity of brain MRI for the diagnosis of CJD, allowing the detection of some cases that would have been overlooked by conventional sequences.