In vivo Proton Magnetic Resonance Spectroscopy of Brain Tumors

Abstract

The ability of magnetic resonance spectroscopy (MRS) to differentiate neoplastic brain cells and their metabolic and structural characteristics is evaluated. We examined 120 patients with brain tumors using a 1.5-tesla MRI unit and MRS. The peak areas of N-acetyl-aspartate (NAA), phosphocreatine-creatine (Pcr-Cr), choline-containing compounds (Cho), lactate, lipids, myoinositol, amino acids and the ratios of NAA/Pcr-Cr, NAA/Cho and Cho/Pcr-Cr were calculated by a standard integral algorithm. In normal brain tissue, the following metabolites were identified: NAA at 2.0 ppm, Pcr-Cr at 3.0 ppm and Cho at 3.2 ppm. The different concentrations of the metabolites examined and their role in the biochemical profile of different types of tumors are discussed. The confidence interval of the MRS versus pathology was between 0.9 and 0.954, while it was between 0.52 and 0.631 for MRI versus pathology. The Cho/Pcr-Cr ratio is a very important malignancy marker for histologic tumor grading of astrocytomas. The greater this ratio, the higher the grade of the astrocytoma. NAA/Pcr-Cr together with Cho/Pcr-Cr help specify the presence or absence of a neoplasm. Proton MRS is a useful and promising diagnostic modality not only in diagnosing but also in grading solid brain tumors.

Temporal pole proton preoperative magnetic resonance spectroscopy in patients undergoing surgery for mesial temporal sclerosis

“…The importance of signal contamination from a misplaced voxel has been adequately addressed in the literature. 10 In our current study, the voxel placement was manual and this was done with extreme caution by experienced spectroscopists. In addition, the proximity of bone and muscle tissue to the temporal fossa may influence the accuracy of the obtained spectra in rare instances.…”

The Role of Magnetic Resonance Spectroscopy in the Diagnosis of Ring Enhancing Lesions

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“…The clinical use of proton MR spectroscopy presents several technical limitations and pitfalls [Castillo et al, 1996;Fountas et al, 2000;Preul et al, 1996;Rand et al, 1999;Shukla-Dave et al, 2001]. Proton MRS lasts approximately 15 min and requires the patient's cooperation for avoiding motion artifacts.…”

“…Cerebral abscesses contain no normal neurons and no membranous structures in their necrotic lesional center (Fountas et al, 2000;Lai et al, 2005). Therefore, no peaks of NAA, Cr, or Cho should be detected.…”