Predicting the histopathological grade of cerebral gliomas using high b value MR DW imaging at 3-tesla

Abstract

BACKGROUND: Our aim was to prospectively assess whether magnetic resonance (MR) diffusion-weighted (DW) imaging using high b values can predict better than b value of 1,000 s/mm2 the histopathological grade of cerebral gliomas. METHODS: Fifty-four patients with histologically verified brain gliomas (35 high-grade and 19 low-grade gliomas) underwent MR DW imaging. Isotropic DW images and apparent diffusion coefficient (ADC) were obtained with b values of 1,000 and 3,000 s/mm2. Each tumor was evaluated as being hyperintense, iso-intense or hypointense to normal, contralateral-hemisphere white matter. RESULTS: Most of the patients with high- and low-grade gliomas showed areas of increased signal intensity on their isotropic images, obtained with a b value of 1,000 s/mm2. However, with a b value of 3,000 s/mm2 the areas of increased signal intensity were seen in 97.1% of the high-grade gliomas, while 94.7% of the low-grade gliomas showed no area of increased signal intensity. The mean area under the ROC curve for ADC ratio, obtained with a b value of 3,000 s/mm2, was significantly higher than that obtained with 1,000 s/mm2 (.932 vs.856, P =.04). CONCLUSION: High b value DW MR might be useful as a complementary tool in preoperative assessment of the histopathological grading of cerebral gliomas. © 2008 by the American Society of Neuroimaging.