Evaluation of Brain Lesions Using Magnetic Resonance Spectroscopy

Abstract

Aims: This study designed to describe the spectrum of Magnetic Resonance in brain lesions and to show its diagnostic importance in differentiating neoplastic, non-neoplastic and other lesions. Also to show the importance of MRS in differentiating of other brain lesions and correlate MRS findings with histopathological findings. Study Design: This is a prospective study included 30 patients with intracranial tumors underwent MR imaging, proton MR spectroscopy, and stereotactic biopsy. Place and Duration: The study was carried out in the Department of Diagnostic Radiology, Royal Care International Hospital, Sudan. June 2015 to June 2016.   Methodology: MRS studies were performed with 1.5 Tesla Toshiba whole body MR systems using standard imaging head coil. All spectroscopy images were performed through single voxel technique. MR spectroscopic findings were evaluated for the distribution pattern of pathologic spectra (N-acetylaspartate (NAA)/ choline [1] ratio > 1) across the lesion and neighboring tissue. Results: The result of this study revealed that the characteristic features in malignancy were increased Cho/creatine (Cr) peaks with NAA remains unchanged, the increased Cho/Cr and Cho/NAA ratio also noted with glioma. Furthermore grading of glioma as high or low can be obtained on the basis of Cho/Cr and the presence of lipid/lactate peak. In this study, there was total agreement between MRS, and histopathologicaly results. In addition, the study showed that the specific MR spectroscopic findings for meningioma were the absence or very small peak of neuronal markers NAA and Cr, and markedly elevated Cho. Conclusion: Diagnosis of primary and secondary brain tumors and differentiating them from other focal intra-cranial lesions based on imaging procedures alone is still a challenging problem, combination of proton MRS and conventional MRI protocol can provide additive valuable information helping in tissue characterization of intra-cranial tumors leading to improved diagnosis and thus reducing biopsies.