Absolute quantification in proton magnetic resonance spectroscopy is superior to relative ratio to discriminate Alzheimer's disease from Binswanger's disease.

BACKGROUND/AIMS: Although many proton magnetic resonance spectroscopy studies have assessed the relative ratios of brain metabolites from patients with dementia, absolute quantification is rare. The aim of this study is to compare the diagnostic accuracy of these 2 methods in proton magnetic resonance spectroscopy in discriminating Alzheimer's disease (AD) and Binswanger's disease (BD) from healthy controls (HC).

METHODS: The subjects were 30 AD patients, 13 BD patients and 26 HC subjects. Single-voxel proton MR spectra at short echo times were acquired from 8 volumes of interest.

RESULTS: At 80% specificity, the absolute N-acetylaspartate concentration in the hippocampus was the most sensitive measure to discriminate AD from HC, and the absolute N-acetylaspartate concentration in the anterior periventricular and deep white matter to differentiate BD from HC and AD. No relative ratio using creatine as a reference had a sensitivity over 80% at 80% specificity. The cause of disparities between the 2 methods was attributed to fluctuations in the creatine concentration.

CONCLUSION: Our study revealed that absolute quantification is superior to relative ratio to differentiate AD and BD from HC.