ABSTRACT
Objective To assess the diagnostic value of diffusion-weighted echo-planar MR Imaging (DWI) in ring-enhancing intracerebral lesions. Methods Magnetic resonance diffusion-weighted images of ninty-three patients presenting with ring-ehancing intracerebral lesions diagnosed by clinical or histopathologic findings were studied retrospectively, including 21 gliomas, 26 metastases, 13 pyogenic abscesses, 18 neurocysticercoses and 15 subacute intracerebral hematomas. The signal intensity ratio on diffusion-weighted images and exponential diffusion coefficient images was calculated respectively in ring walls, central contents, and perilesional edemas of ring-enhancing lesions, and normal contralateral cerebral parenchyma was used for comparison. ADC values of interest of lesions, contralateral cerebral parenchyma and CFS were calculated as well. Results In pyogenic abscesses and subacute intracerebral hematomas, the central content was always extremely hyperintense on diffusion-weighted images, and showed low ADCs[(0.56?0.20)?10~ -3 mm~2/s, (0.69?0.16)?10~ -3 mm~2/s, respectively]. On the other hand the central content of gliomas, metastases and neurocysticercoses was hypointense, and showed high ADCs [ (2.76?0.41)?10~ -3 mm~2/s, (2.31?0.39)?10~ -3 mm~2/s, (2.10?0.32)?10~ -3 mm~2/s, respectively]. The ADCs of the first two lesions were significantly lower than of the last three lesions (P