title: Could assessment of glioma methylene lipid resonance by in vivo (1)H-MRS be of clinical value?
abstract: The potential clinical role of in vivo (1)H-MRS ((1)H-magnetic resonance spectroscopy) lipid methylene resonance measurements of human glioma has been assessed. 20 patients, 14 with low grade and 6 with high grade gliomas have been investigated using single voxel (1)H-MRS. Three of the low grade group had undergone transformation by clinical and imaging criteria. Short echo time (TE=20 ms, TR=2500 ms) single voxel Stimulated Echo Acquisition (STEAM) spectra with (acquisitions=64) and without (acquisitions=4) water suppression were acquired. Additionally, T(1) weighted (T(1)W) water spectra (TE=20 ms, TR=888 ms) were acquired pre- and post-injection of Gd-DTPA (0.2 mmol x kg(-1)). The T(1)W water spectra were used to determine the water proton enhancement occurring within the spectroscopic voxel. The enhancement expressed as a percentage was compared with the lipid methylene peak. All the high grade tumours had significantly higher levels of lipid than low grade tumours (p=0.002). Low grade tumours had significantly less water proton enhancement than transformers (p=0.04) and high grade tumours (p=0.001). The lipid methylene signal correlated strongly with the voxel water enhancement (r(2)=0.74, p<0.0001). The data support the view that the spectroscopically detected lipid methylene signal may be a useful criterion in grading glioma. The correlation of the lipid methylene signal with blood-brain barrier breakdown suggests that detection of a previously absent (1)H-MRS lipid methylene signal in low grade tumours might be an early indicator of transformation.
authors.affiliation: Cancer Research UK Clinical MR Research Group, The Institute of Cancer Research and The Royal Marsden NHS Trust, Sutton, Surrey SM2 5PT, UK.
authors.forename: P S
authors.initials: PS
authors.lastname: Murphy
authors.forename: I J
authors.initials: IJ
authors.lastname: Rowland
authors.forename: L
authors.initials: L
authors.lastname: Viviers
authors.forename: M
authors.initials: M
authors.lastname: Brada
authors.forename: M O
authors.initials: MO
authors.lastname: Leach
authors.forename: A S K
authors.initials: AS
authors.lastname: Dzik-Jurasz
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism*; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D005910:Glioma / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D006838:Hydrocarbons; D050356:Lipid Metabolism; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008697:Methane / Q000031:analogs & derivatives* / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D006838:Hydrocarbons; C030011:carbene; D008697:Methane