RT Journal Article
SR Electronic
T1 Enhanced Detection of Diffusion Reductions in Creutzfeldt-Jakob Disease at a Higher B Factor
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 49
OP 54
DO 10.3174/ajnr.A1756
VO 31
IS 1
A1 H. Lee
A1 C. Hoffman
A1 P.B. Kingsley
A1 A. Degnan
A1 O. Cohen
A1 I. Prohovnik
YR 2010
UL http://www.ajnr.org/content/31/1/49.abstract
AB BACKGROUND AND PURPOSE: Diffusion-weighted imaging (DWI) is sensitive to the cerebral manifestations of human prion diseases. The magnitude of diffusion weighting, termed “b factor,” has only been evaluated at the standard b = 1000 s/mm2. This is the first rigorous evaluation of b = 2000 s/mm2 in Creutzfeldt-Jakob Disease (CJD). MATERIALS AND METHODS: We compared DWI characteristics of 13 patients with CJD and 15 healthy controls at b = 1000 s/mm2 and b = 2000 s/mm2. Apparent diffusion coefficients (ADC) were computed and analyzed for the whole brain by voxel-wise analysis (by SPM5) as well as in anatomically defined volumes of interest (by FSL FIRST). RESULTS: Measured ADC was significantly lower (by approximately 5%–15%) at b = 2000 s/mm2 than at b = 1000 s/mm2 and significantly lower in patients than in controls. The differences between patients and controls were greater and more extensive at b = 2000 s/mm2 than at b = 1000 s/mm2 in the expected regions (thalamus, putamen, and caudate nucleus). CONCLUSIONS: Because higher b factors change the absolute value of observed ADC, as well as lesion detection, care should be taken when combining studies using different b factors. While the clinical application of high b factors is currently limited by a low signal intensity–to-noise ratio, it may offer more information in questionable cases, and our results confirm and extend the central role of diffusion imaging in human prion diseases.