MAGNETIC RESONANCE SPECTROSCOPY IN THE DIAGNOSIS AND ETIOLOGICAL DEFINITION OF BRAIN BACTERIAL ABSCESSES

ABSTRACT- We report two patients with bacterial brain abscesses whose etiological diagnosis was correct-ly 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 diffu-sion. On MRS, the abscess caused by aerobic bacteria presented lactate and aminoacids peaks and the ab-scess 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. Convention-al MRI, associated with DWI and MRS is effective in diagnosing bacterial abscess and promising in explor-ing its etiology. KEY WORDS: pyogenic bacterial abscess, spectroscopy, diffusion, magnetic resonance. Espectroscopia por ressonância magnética no diagnóstico e definição etiológica dos abscessos bacteria-nos cerebrais RESUMO- Apresentamos dois pacientes com abscessos bacterianos cerebrais cujos diagnósticos etiológicos foram corretamente auxiliados pela associação de difusão e espectroscopia à ressonância magnética con-vencional. Ambos apresentavam lesões com captação anelar de contraste e evidências de restrição à difu-são de moléculas de água. Na espectroscopia, o abscesso causado por bactéria aeróbia apresentou picos d