The MR images of 13 patients with brain abscesses were retrospectively reviewed. The abscesses were solitary in 11 patients and multiple in 2 patients. They were located in the cortivomedullary junction of the cerebral hemispheres (11) and cerebellum (2).: The sizes of the abscesses were variable, ranging from 1 cm to 5 cm in diameter. They were round (5), oblong (4) or multilobulated (4) in shape. Massive surrounding edema was found in 12 patients. The signal intensity of the abscess contents was hypointense to gray matter and hyperintense to CSF on T1-weighted images. In 5 patients the abscess contents were heterogeneous on both T1-and T2-weighted images. The signal intensity of the abscwss walls was isointense (11), slightly hyperintense (1) or hypointense (1) relative to gray matter on T1-weighted images, whereas they were isointense (4) or hypointense (9) on T2-weighted images. Of 10 patients with Gd-enhanced-T1-weighted images, 5 patients (50%) showed thin, smooth, rim e hancement, while the other 5 patients revealed somewhat irregular thick wall engancement. Satellite or daughter abscesses were found in 6 patients. Meningeal or ventricular wall enhancement suggesting menigitis or ventriculitis was associated in 3 and 1 patient, respectively. In conclusion, the characteristic morphology and intensity of the abscess capsule, massive surrounding edema, satellite abscess and associated meningitis or ventriculitis are characteristic of the brain abscess, even though they are not entirely specific to allow for accurate diagnosis in all patients.