ADDED VALUE OF AUTOMATED CLINICAL PROTON MR SPECTROSCOPY OF THE BRAIN

Objective: A trial was conducted to establish the added diagnostic val ue of an automated proton MR spectroscopy (MRS) examination (PROBE). M aterials and Methods: The PROBE and MRS were compared for metabolite r atios of normal controls and 21 patients. In addition, PROBE was perfo rmed in either the occipital cortex (gray matter) or the parietal cort ex (white matter) or, more rarely, within the confines of a focal lesi on identified on MRI, using a GE Signa 1.5 T whole-body scanner, in 11 2 patients undergoing routine brain MRI. The trial was conducted in th ree different MR centers to establish percentage of positive findings with MRI vs, MRI plus MRS. Results: Cerebral metabolite ratios (N-acet ylaspartate/creatine, choline/creatine, myo-inositol/creatine) obtaine d by PROBE and MRS were similar. Metabolite profiles in dementia, head trauma, herpes encephalitis, hepatic and hypoxic encephalopathy, stro ke, and tumor were identified using PROBE. The PROBE technique increas ed the number of positive findings (''added value'') achieved by MRI; the added value was 28, 21, and 93% for the three trial sites. Conclus ion: With only minor variations, PROBE reproduces the cerebral metabol ite patterns obtained with MRS. It significantly increases the diagnos tic yield of routine neuroimaging and might be incorporated as a stand ard sequence in a cost-effective manner.