Persistent enhancement after treatment for cerebral toxoplasmosis in patients with AIDS: predictive value for subsequent recurrence.

PURPOSE: To determine the predictive imaging (CT and/or MR) features of brain toxoplasmosis recurrences in acquired immunodeficiency syndrome.

METHODS: The imaging studies of patients with brain toxoplasmosis were retrospectively reviewed. Forty-three patients with significant decrease or disappearance of brain lesions under specific treatment on follow-up imaging examinations were included. MR examinations were performed using T2- and T1-weighted sequences, before and after intravenous administration of gadolinium-DOTA.

RESULTS: A recurrence occurred in 11 (26%) of 43 cases. Ten (91%) of these 11 patients with recurrence showed focal persistent enhancement after the initial treatment of toxoplasmosis abscess. One of the 11 patients with recurrence showed no persistent enhancement; 3 patients showed persistent enhancement but had no recurrence.

CONCLUSIONS: Recurrences of brain toxoplasmosis in our series correlated with persistent contrast enhancement. We hypothesize that demonstration of persistent areas of contrast enhancement after treatment for initial toxoplasmosis may be a valuable sign for identifying patients at risk for recurrence.