PATHOLOGICAL FINDINGS CORRELATED WITH MRI IN HIV-INFECTION

MRI forms an important part of the assessment of patients with HIV-rel ated disease presenting with cerebral smyptoms. Eleven formalin-fixed brains were studied at 0.5 T using T2- and T1-weighted sequences. In t wo cases of progressive multifocal leucoencephalopathy and one case ea ch of toxoplasmosis and lymphoma, the extent of white matter abnormali ty seen on MRI corresponded broadly with that on pathological examinat ion. In general, however, histological changes were more frequent than lesions on MRI. Cases in which abnormalities were not seen with stand ard MRI included those with multiple tuberculous granulomata, multinuc leate giant cells, microglial nodules, perivascular cuffing and cytome galovirus inclusions. A common finding on MRI was punctate or patchy h igh signal in the basal ganglia on T2-weighted scans, seen in six case s. Corresponding histological changes included calcification of vessel s with widened perivascular spaces, and mineralised neurones.