Proton magnetic resonance spectroscopy: clinical applications in patients with brain lesions

Abstract

CONTEXT: Proton spectroscopy has been recognized as a safe and noninvasive diagnostic method that, coupled with magnetic resonance imaging techniques, allows for the correlation of anatomical and physiological changes in the metabolic and biochemical processes occurring within previouslydetermined volumes in the brain. There are two methods of proton magnetic resonance spectroscopy: single voxel and chemical shift imaging OBJECTIVE:The present work focused on the clinical applications of proton magnetic resonance spectroscopy in patients with brain lesions. CONCLUSIONS:In vivo proton spectroscopy allows the detection of certain metabolites in brain tissue, such as N-acetyl aspartate, creatine, choline, myoinositol, amino acids and lipids, among others. N-acetyl aspartate is a neuronal marker and, as such, its concentration will decrease in the presence of aggression to the brain. Choline increase is the main indicator of neoplastic diseases. Myoinositol is raised in patients with Alzheimer's disease. Amino acids are encountered in brain abscesses. The presence of lipids is related to necrotic processes.

Análise do masseter, por espectroscopia de próton, em pacientes com esclerose sistêmica

“…Creatine levels remain stable in the brain tissue in several diseases (21,23) , however this assertion is not valid for the musculoskeletal system, considering that some studies about the energy metabolism in rheumatic diseases have demonstrated variable results. By submitting lower limb muscles to 31 P-MRS, some studies have observed increased inorganic phosphate/ phosphocreatine levels in patients with systemic sclerosis and polymyositis (15,25) , which indicates the presence of ischemic muscle disease.…”

“…Proton magnetic resonance spectroscopy ( 1 H-MRS) was chosen considering that hydrogen is the most abundant atom in the organism, with higher sensitivity, easy performance and interpretation, besides the capacity to investigate a higher number of metabolites as compared with phosphorus spectroscopy ( 31 P-MRS) (21,22) .…”

“…In the same way as creatine, no significant difference in lipid levels was observed among the three groups. Increased lipid concentration is related to cell degradation and necrosis (21) , and this increase was observed in patients with temporomandibular joint disorder (24) .…”

Proton magnetic resonance spectroscopy and apparent diffusion coefficient in evaluation of solid brain lesions

“…In this research we did not observe lactate peaks. Loss of neuronal cells leades to decreas of NAA and increase of Cho level is due to reactive gliosis 23,24 . The intensity of these metabolite changes reflects the severity of an ischemic process and it is related to the prognosis 24 .…”

Clinical Application of MR Spectroscopy in Identifying Biochemical Composition of the Intracranial Pathologies

“…Lactate is observed within few minutes following brain ischemia and its concentration reduces in sub-acute phase. The intensity of these peaks in the infracted area is related to the prognosis [18].…”