Proton MR Spectroscopy of Intracranial Tumours

TLDR

The study used proton magnetic resonance spectroscopy to investigate intracranial tumours both in vitro and in vivo. Biopsy specimens from 47 patients (11 also scanned in vivo) were analyzed for N‑acetylaspartate, phosphocreatine/creatine, choline, alanine, and lactate signals. The NAA/Cr ratio varied with tumour grade, the Cho/Cr ratio was elevated only in grade IV astrocytomas, meningiomas showed a markedly high Ala/Cr ratio, and in vivo spectra matched in vitro results, with lactate indicating abnormal metabolism, supporting 1H MRS as a valuable diagnostic and monitoring tool.

Abstract

Proton magnetic resonance spectroscopy (1H MRS) was used to investigate intracranial tumours in vitro and in vivo. Biopsy specimens were studied from 47 patients, 11 of whom were also examined in vivo. Analysis was based on the signals from N-acetylaspartate (NAA), phosphocreatine plus creatine (Cr), choline-containing compounds (Cho), alanine (Ala), and lactate. Biopsy data from 26 astrocytomas showed that the NAA/Cr ratio differs significantly in all grades from its value in normal white matter and that the Cho/Cr ratio differs significantly in grade IV tumours from its value in the other grades. Meningiomas have an unusually high Ala/Cr ratio. Spectra obtained in vivo are consistent with in vitro results from the same patients, and their lactate signal provides additional information about abnormal metabolism. We conclude that 1H MRS has a clear role in the diagnosis and biochemical assessment of intracranial tumours and in the evaluation and monitoring of therapy.