title: Short echo-time proton magnetic resonance spectroscopy in regions of severe HIV-related diffuse white matter abnormality on MRI.
abstract: The purpose of this study was to determine whether short echo-time proton magnetic resonance spectroscopy (H-MRS) could detect mobile lipid resonances attributable to myelin breakdown products in the deep cerebral white matter of patients with AIDS who have severe diffuse/patchy white matter hyperintensity on T2-weighted magnetic resonance imaging (MRI). Seven patients with AIDS and clinical HIV-associated dementia complex (HADC) and 12 male controls were studied at 1.5T using a single 8 ml voxel, gradient localised, stimulated echo acquisition mode (STEAM) spectroscopy sequence. Spectra were acquired at an echo time of 20 ms with a repetition time of 5000 ms. No spectroscopic peaks were identified at 0.9 ppm and 1.3 ppm (corresponding to lipid resonances) in 6 of the 7 patients with AIDS or in any of the controls. Lipid resonances were identified in 1 patient who had been taking anti-retroviral therapy for 8 weeks. Follow up MRI/H-MRS, performed after a further 14 weeks of anti-retroviral therapy, showed partial resolution of white matter hyperintensity and lipid resonances were not detectable. These data suggest that mobile lipids are only rarely detected by H-MRS in patients with HADC and abnormalities on MRI and that their presence may be transitory.
authors.affiliation: Department of Medical Physics and Bioengineering, London, England. iain@medphys.ucl.ac.uk
authors.forename: I D
authors.initials: ID
authors.lastname: Wilkinson
authors.forename: R F
authors.initials: RF
authors.lastname: Miller
authors.forename: M A
authors.initials: MA
authors.lastname: Hall-Craggs
authors.forename: M N
authors.initials: MN
authors.lastname: Paley
authors.forename: M J
authors.initials: MJ
authors.lastname: Harrison
mesh_terms: D020943:AIDS Arteritis, Central Nervous System / Q000175:diagnosis* / Q000473:pathology; D017088:AIDS-Related Opportunistic Infections / Q000175:diagnosis / Q000473:pathology; D000328:Adult; D001921:Brain / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged