Reliability of computed tomography in assessing histopathological features of malignant supratentorial gliomas.

A new method was developed whereby close comparisons can be made between components of a computed tomography (CT) image and neuropathological findings. This was achieved by a combination of intravital (terminal) CT, postmortem CT, and whole brain sectioning of formalin-fixed tissue. The method was applied in seven cases of malignant supratentorial astrocytic gliomas (Kernohan Grades III and IV) and in one case of thalamic ependymoma. The glioblastoma-like parts of the astrocytic gliomas were usually correctly delineated by postcontrast CT, although there were exceptions to this rule. Tumor components consisting of diffusely growing malignant astrocytoma were difficult or impossible to delineate by CT. Necrotic areas within the tumors were accurately outlined by postcontrast CT. Peritumoral edema was correctly delineated by CT, but growth of diffuse astrocytoma or the presence of astrocytic gliosis within this edematous area seems difficult or impossible to evaluate by current CT techniques.