In Vivo proton MR spectroscopy of human gliomas: definition of metabolic coordinates for multi‐dimensional classification

Abstract

Several multi-dimensional statistical evaluation methods were applied to single-voxel proton MR spectra of glial brain tumors and of healthy volunteers. Metabolic coordinates with histological relevance for future diagnosis were found by which spectra from controls, low-grade tumors, and high-grade tumors were completely separated. Significant differences between low-grade and high-grade glioma patients and controls were found for several metabolic ratios by variance analysis. Cluster analysis both with and without principal component analysis was applied. The outcome of these two approaches depended mainly on the lipid-to-creatine ratio. Two other approaches, discriminant factor analysis and the orthonormal discriminant vector method were then used to find discriminatory metabolic coordinates. It turned out that a linear combination of all evaluable metabolic ratios made it possible to separate the three groups completely. On the basis of these results, a classification method that uses the entire proton MRS spectrum is proposed.

Arterial Spin-Labeling and MR Spectroscopy in the Differentiation of Gliomas

“…These short T2 metabolites play an important role in the diagnosis and characterization of brain tumors. 10,13,53 Majó s et al 54 have also advocated the use of short TE 1 H-MR spectroscopy to classify tumors into different grades. In our study, we used a short TE (30 ms), and we assigned the resonance at 1.3 ppm as a combination of both Lac and Lip.…”

Metabolic profiles of human brain tumors using quantitative in vivo 1H magnetic resonance spectroscopy

“…An increase in the Cho/Cr ratio (or decrease in the Cr/Cho ratio) in tumors is generally correlated with increase in tumor malignancy and is used as a possible noninvasive index of tumor grade (9). Shortecho time (TE ϭ 12-30 ms) studies also show that the level of myo-Inositol (mI) may aid tumor classification and grading (3,4,11,12). In short-TE spectra there can also be large signals from mobile lipids and macromolecules, particularly in high-grade tumors, and lipid quantitation may be relevant as an indicator of grade (10,12,13).…”

Identification and characterisation of childhood cerebellar tumours by in vivo proton MRS

“…Potential roles have been identified in pre-surgical diagnosis of tumour type and grade (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19), monitoring of treatment response (20), and evaluation of tumour recurrence (21). However, optimised MRS analysis is required to enable the widespread clinical use of the technique.…”

“…However, optimised MRS analysis is required to enable the widespread clinical use of the technique. Pattern classification of MRS data alone or in combination with MRI features has proven successful for accurately classifying brain tumours (1,(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17). Although brain tumours are the most common solid tumours in children and a major cause of childhood mortality, they are rarer than in adults, and only small numbers have been reported in the few studies using MRS to discriminate paediatric brain tumours (15)(16)(17)(18)(19).…”