Reliable early diagnosis of Alzheimer’s disease (AD) is a clinical challenge; no single diagnostic test exists. Localised proton magnetic resonance spectroscopy (MRS) is a relatively new, non-invasive examination that is used to assess in-vivo brain metabolism, and clinical studies 1,2 have shown high levels of brain myoinositol in-vivo in AD. These studies used relatively high field strengths of 1·5 Tesla or above, were done in academic institutions or teaching hospitals, and involved time-consuming manual spectroscopy. We assessed in-vivo brain MRS with an automated technique in a lowerfield (1·0 Tesla) clinical scanner in a district general hospital. 28 patients from the Memory Clinic were recruited. All had a clinical diagnosis of dementia made on DMS-IIIR criteria. Of the 28 patients, 13 had AD and 15 had multiinfarct dementia (MID). The latter group had Hachinski ischaemia scores 3 of over 7 and findings of vascular disease on magnetic resonance imaging (MRI) or computed tomography scan. 11 of the 13 patients with AD and 12 of the 15 patients with MID were followed up for at least 12 months after MRS. Brain MRS examinations were done with a stan dard birdcage headcoil and a single voxel, stimulated echo acquisition mode (STEAM), which was automated. Acquisition details for spectra using STEAM were: repetition time (TR) 1500 ms, echo time (TE 30 ms, mixing time (TM) 13·7 ms, and number of acquisitions 128. The volume of tissue (8 cm 3 voxel), from which the MRS metabolite data were obtained, was located in the mid-line of the occipital lobes. No focal structural abnormalities in the occipital lobes were detected with conventional magnetic resonance imaging (MRI) in these patients. Acquisition of spectra took approximately 10 min when done with a standard MRI examination. From the spectra (figure, left) the ratios of the peak amplitudes of the metabolites NAA (N-acetyl-aspirate), Cho (choline-containing compounds), Glx (glutamate and glutamine), and MI (myoinositol) relative to Cr (creatinine/phosphocreatine) peak were calculated. Metabolite measurements were made blinded to clinical details. The results (below), showed a significantly higher ratio of MI/Cr in patients with AD compared with those with MID (t=5·96, p<0·0001): AD MID Age (years) 78·4+7·6