Reliability of computed tomography: correlation with neuropathologic findings.

Findings on cranial computed tomography (CT) were correlated with autopsy findings in 58 cases with 129 lesions to determine CT reliability. When only CT scans of good quality were considered, there were no false positive cases. The number of false negative studies varied directly with lesion size: one of 42 lesions larger than 2.5 cm; four of 12 lesions between 1.5 and 2.5 cm; 12 of 15 between 0.5 and 1.5 cm; and all 21 of those smaller than 0.5 cm. Lesion size was undetermined in the remaining 18 casesbecause of the nature of the disease. While the series is small, these results suggest that the current detector threshold for CT may be in the range of 0.5-1.5 cm, although smaller lesions may be seen if there is substantial surrounding edema.