Correlation between magnetic resonance imaging and histopathology of intracranial glioma.

Postmortem histopathology of eight gliomas was studied in correlation with magnetic resonance imaging (MRI) and computed tomography (CT) findings. MRI demonstrated the lesions more clearly and widely than CT. Also, T2-weighted images (T2WI) had a greater ability to depict the lesion than T1-weighted images (T1WI). The areas in which neoplastic cells had invaded corresponded to the high intensity areas on T2WI in four cases of glioblastoma multiforme. In the case of a grade II astrocytoma, neoplastic cells were scattered beyond the region corresponding to the high intensity area on T2WI. In the case of a grade III astrocytoma, neoplastic cells did not come up to the line corresponding to the margin of the high intensity area on T2WI. In the remaining two cases, although the high intensity areas on T2WI were depicted as being larger than the areas in which neoplastic cells were seen histopathologically, the high intensity regions corresponding to the outside zones of the tumour-infiltrated area were thought to be a radiation necrosis in one case and a 'periventricular high intensity' in the other. The high cellularity of the glioma was seen mainly as a low intensity area on T1WI and as an isointensity or a slightly high intensity area on T2WI. However, the signal intensities of glioma on MRI, reflecting T1 or T2 values of the tumour tissues, did not correlate with the malignancy of the tumour.