Astrocytic gliomas: MRI and pathological grade.

The relationship between MR configuration and pathological grade was studied in 41 histologically verified supratentorial astrocytic gliomas with a 0.5T superconductive MR system. The gliomas included 13 low-grade astrocytomas (LGAs), 14 anaplastic astrocytomas (AAs) and 14 glioblastoma multiformes (GBMs). MRI configurations were classified into nine criteria which were scored and statistically analyzed. The mean values of LGAs, AAs and GBMs were 0.45 +/- 0.31, 1.18 +/- 0.20 and 1.47 +/- 0.22. In each grade, MRI score increased as pathological grades increased (p < 0.01-0.001). LGAs had significantly lower values than AAs in five of the nine criteria (55.6%); heterogeneity, cyst or necrosis, edema or mass effect, border definition, and the degree of contrast enhancement, and lower values than GBMs in eight criteria (88.9%) except for hemorrhage. Three criteria (33.3%), heterogeneity, cyst or necrosis, and flow void sign were significantly higher in GBMs than AAs. The four variables, heterogeneity, cyst or necrosis, edema or mass effect and border definition, proved to be important factors related to the pathological grade in a multiple regression analysis.