Metabolism of human gliomas: assessment with H-1 MR spectroscopy and F-18 fluorodeoxyglucose PET.

Abstract

Localized hydrogen-1 magnetic resonance (MR) spectroscopy and fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) were employed to obtain metabolic information from intracranial gliomas. Advantages and difficulties associated with comparison of results from the two modalities were realized. Forty patients were studied with H-1 MR spectroscopy. MR signal intensities from lactate, N-acetylaspartate (NAA), choline, and creatine from a volume of interest containing the tumor and a contralateral volume were obtained and evaluated. NAA signal intensities were generally decreased in the tumor spectra, and choline signal intensities were elevated. H-1 MR spectroscopy was unsuccessful in eight patients, and FDG PET scans were not obtained in four of the patients with successful MR spectroscopic examinations. Lactate signal intensity was detected in 10 of the 28 patients who had successful H-1 MR spectroscopic and FDG PET studies. Lactate signal intensities were observed in lesions shown at FDG PET to be hypermetabolic, as well as in lesions found to be hypometabolic.

Reproducibility of Proton Magnetic Resonance Spectroscopic Imaging in Patients with Schizophrenia

“…Localized 1 H-MRS has been used to study a variety of brain disorders, including multiple sclerosis (Roser et al 1995), neoplasm (Alger et al 1990), epilepsy (Connelly et al 1994), Down's syndrome (Murata et al 1993), Huntington's disease (Jenkins et al 1993), and schizophrenia (Yurgelun-Todd et al 1996;Renshaw et al 1995;Nasrallah et al 1994;Maier et al 1995;Buckley et al 1994;Fukuzako et al 1995). 1 H-MRS has recently evolved to multislice 1 H-MRS imaging ( 1 H-MRSI) that permits imaging of signals arising from a large number of small single-volume elements (nominal volume resolution of 0.84 mL) within multiple whole brain slices, thus enabling mapping of the spatial extent of chemical abnormalities with improved resolution (Duyn et al 1993).…”

Method to correlate1H MRSI and18FDG-PET

“…Earlier studies have combined 18 FDG-PET with NAA measures using single-voxel (21)(22)(23) or SI methodologies (24 -27). However, none of these studies accounted rigorously for the different image resolutions of PET and MRS.…”

Brain MRI: Tumor evaluation

“…The increase in Cho is attributable to accelerated cell membrane synthesis and turnover (21)(22)(23)(24); however, Cho is underestimated and may be unreliable in heterogeneous tumors due to internal hemorrhage, necrosis, or cysts (25,26). Cr is a marker of cellular energetics and is decreased due to higher tumor metabolism and greater consumption of energy.…”