¹H mrs of human brain abscesses in vivo and in vitro

Abstract

Five patients, each with a brain abscess, were examined by means of 1H MR spectroscopic imaging in vivo. The aspirated pus was analyzed in vitro by means of 1D and 2D COSY 1H MRS. In addition to resonance lines from compounds (lactate, alanine and lipids) often found in the spectra from intracranial tumors, resonance lines were detected from a number of markers of infectious involvement (acetate, succinate, and various amino acids). These results suggest that 1H MRS in vivo might contribute in establishing noninvasively a differential diagnosis between brain abscess and tumor.

Brain abscess: surgical experiences of 162 cases

“…[9] Positive labeling in radionuclide imaging with III-Indium labeled leukocytes, C-reactive protein, 99m TC-hexamethylpropylene amine oxime leukocyte scintigraphy, diffusion weighted MRI, Thallium-201 GCS: Glasgow Coma Scale single photon emission CT, and proton MRS are helpful in differentiating abscess from tumor. [31][32][33][34][35][36][37][38] Brain abscesses were singular in 77.7% of the subjects and multiple in 22.3%, a result similar to that reported by Landriel et al [39] The frontal lobe was the most common abscess location in the patients, followed by the temporal and occipital regions. However, in a study carried out by Cavusoglu et al, [40] the temporoparietal region was the most commonly affected location.…”

In Vivo Proton MR Spectroscopy Evaluation of Pyogenic Brain Abscesses: A Report of 194 Cases

“…27 Nonvisibility of the resonance of Ac with or without Suc on in vivo 1 H-MR spectroscopy in 41% of anaerobic culture-positive brain abscesses in our study could be explained by the relatively low concentration of these metabolites, which might be below the sensitivity of the current scanner. 28 Suc and Ac are usually not observed in brain abscesses secondary to aerobic (Fig 4) and facultative anaerobic microorganisms because the pyruvate formed during glycolysis enters the tricarboxylic acid cycle in these bacteria in the presence of oxygen. 8 In accord with the literature, we did not observe these resonances in any of the aerobic brain abscesses.…”

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

“…Both patients showed amino-acid signals at 0.9 ppm, seen in many brain abscesses and assigned to valine, leucine, and isoleucine, considered representing accumulated end-products of proteolysis caused by proteolytic enzymes secreted by microorganisms or polymorphonuclear leukocytes in pus, or both [16][17][18][19][20][21][22] . Patient 2, infected by an anaerobe facultative bacteria, presented acetate and succinate, considered being the end products of homolactic and heterolactic fermentation and key markers of bacterial infection [23][24][25] .…”