Value of diagnosis and differential diagnosis of MRI and MR spectroscopy in gliomatosis cerebri

PURPOSE: The purpose of this study was to characterize gliomatosis cerebri on magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS), and to analyze the value of these two techniques in diagnosis and differential diagnosis of gliomatosis cerebri. MATERIALS AND METHODS: MR images of 14 patients with gliomatosis cerebri were reviewed retrospectively; seven of the patients also underwent MRS (single-voxel point-resolved spectroscopy, and chemical-shift imaging point-resolved spectroscopy). Tumorous were confirmed by surgery and biopsy. The distribution, extension and signal features of lesions were assessed, and the MR spectroscopy results were analyzed. RESULTS: Tumors involved at least two lobes of the brain in all patients. Widespread invasion with isointensity or hypointensity on T1-weighted MR images and hyperintensity on T2-weighted images were found while no prominent necrosis, hemorrhage or contrast enhancement was found. All patients who underwent MRS showed elevated Cho/Cr and Cho/NAA levels as well as decreased NAA/Cr ratios in the abnormal areas on T2-weighted images, three of which showed a lactate doublet. Anaplastic lesions had higher Cho/NAA levels in three cases. Abnormality of metabolism was also seen in the margin of the lesion that was normal on T2-weighted images. CONCLUSION: MRI and MRS are valuable techniques for diagnosis and differential diagnosis of gliomatosis cerebri. Combining clinical information and MRI findings, as well as MRS, is crucial for making a definitive diagnosis.