ROLE OF IN-VIVO PROTON MAGNETIC-RESONANCE SPECTROSCOPY IN THE DIAGNOSIS AND MANAGEMENT OF BRAIN ABSCESSES

OBJECTIVE: In vivo proton magnetic resonance spectroscopy was performe d for 24 patients with pyogenic brain abscesses, to examine the consis tency of the spectral patterns and to observe the changes in metabolit es with treatment. METHODS: Localized proton spectra were obtained fro m 4- to 8-ml volumes in the abscesses, using stimulated echo acquisiti on mode and spin echo sequences. Twenty-two patients were treated with combined surgical and medical therapy, and two patients were treated conservatively. High-resolution magnetic resonance spectroscopy was pe rformed for 15 samples of abscesses obtained from these patients, to c onfirm the assignments of resonances seen in vivo. Postaspiration stud ies were performed for 12 patients treated with combined medical and s urgical therapy and 2 patients treated medically. RESULTS: Lactate and amino acids were seen in spectra for all patients, irrespective of th e time of spectroscopy after the onset of combined medical and surgica l therapy. Acetate and pyruvate disappeared after 1 week of combined t reatment. CONCLUSION: It was concluded that spectral patterns for brai n abscesses are consistent and specific and can assist in the noninvas ive diagnosis of abscesses. Responses to combined treatment could be m onitored by showing the changes in metabolite patterns in serial spect roscopic studies.