Proton MR spectroscopy in patients with amyotrophic lateral sclerosis (ALS) at 3 Tesla

Abstract

Purpose: The determination of upper motor neuron involvement plays a key role for the diagnosis of amyotrophic lateral sclerosis. Numbers of studies had shown, that proton MR spectroscopy (MRS) allows the detection of neurodegeneration in different brain diseases. Although these studies yielded highly significant differences between patient groups and healthy controls, the diagnosis for the individual case requires further improvement. The correct placement of the volume of interest (VOI) in MRS is important to reduce inclusion of non-target tissue. However, the VOI size used in spectroscopy studies at 1.5 T is often a compromise between gaining sufficient SNR and accepting such partial-volume effects. Increased SNR at high-field MR systems provides the opportunity to reduce VOI size substantially. To potentially improve specificity and sensitivity of the diagnosis of upper motor neuron involvement in ALS patients, VOI size was reduced by a factor of 2 at 3 T.