Magnetic resonance spectroscopy in the diagnosis and etiological definition of brain bacterial abscesses.

We report two patients with bacterial brain abscesses whose etiological diagnosis was correctly proposed by association of diffusion weighted images (DWI) and magnetic resonance spectroscopy (MRS) with conventional MRI. Both patients presented ring enhancing lesions with evidences of restricted diffusion. On MRS, the abscess caused by aerobic bacteria presented lactate and aminoacids peaks and the abscess caused by anaerobic facultative bacteria showed also acetate and succinate peaks. These results are in agreement with an unique previous study that related MRS pattern with bacterial etiology. Conventional MRI, associated with DWI and MRS is effective in diagnosing bacterial abscess and promising in exploring its etiology.