Early diagnosis of brain inflammatory lesion is a basic factor in choosing treatment policy. The paper investigates the use and informative value of diffuse-weighed magnetic resonance imaging in the differential diagnosis of brain abscesses and processes of another origin. It also considers the application of MR spectroscopy and perfusion MRI to obtain additional information on an inflammatory processes. A series of observations covered 10 patients with brain abscesses at different sites. Diffusion-weighed image (DWI) revealed a drastic increase in a MR signal from the central abscess portions (a pyonecrotic area), which is suggestive of decreased diffusion of water molecules. The measured diffusion ratios (MDRs) were significantly lower in the central abscess area (p < 0.005) than those in the capsule and white matter of the brain at all values of the diffuse factor b (500, 1000 sec/mm2); the capsule was better visualized at the DWI at b = 500 sec/mm2. In addition, MDRs were significantly different within the annular contrasting area of abscesses and glioblastomas, in the abscess/tissue capsule, and edema (p < 0.01). Proton spectroscopy of the central abscess area (pus) revealed succinate, acetate, alanine, peaks of lactate and amino acid. Perfusion MR study (bolus contrasting and estimation of the tissue parameters rCBV and MTT) has indicated that the central abscess in relation to the medulla is a decreased perfusion area; perfusion in the abscess capsule is close to that in the medulla in its characteristics, but medullary time in this area is shorter than that in brain tissues; perifocal edema is also characterized by hypoperfusion. The analysis of complex MRI study in patients with brain abscesses has demonstrated that diffuse-weighed MRI enhances diagnostic specificity, diagnoses the development of a pyonecrotic abscess center at early stages of capsule formation; MR spectroscopy is an additional method of differential diagnosis of brain abscess and processes of another nature whereas perfusion MRI provides additional information on medullary hemodynamic changes.