Reproducibility of macromolecule suppressed GABA measurement using motion and shim navigated MEGA-SPECIAL with LCModel, jMRUI and GANNET.

ABSTRACT

OBJECTIVE: Measuring the pure form of GABA has become increasingly important because of its association with behaviour and certain pathologies. The aim of this study was to assess the reproducibility of GABA measurements using a shim and motion navigated MEGA-SPECIAL sequence with LCModel, jMRUI and GANNET software. MATERIALS AND METHODS: Motion and shim navigated MEGA-SPECIAL scans were acquired in 20 healthy subjects. Two acquisitions were performed for each of two regions the anterior cingulate (ACC) and medial-parietal (PAR) cortices. Absolute GABA concentration ([Formula see text]) and GABA-to-Creatine ratio (GABA/Cr) were quantified using the three software packages. RESULTS: Using the within-subject coefficient of variation (CVws) as an index, reproducibility for both GABAH20 and GABA/Cr ranged from 13 to 22 % in the ACC and 13 to 18 % in PAR using the three software packages. CONCLUSION: Based on CVws, GABA concentrations in both the ACC and PAR are reproducible using a shim and motion navigated MEGA-SPECIAL sequence with any of the three software packages, thus demonstrating the ability to quantify the pure form of GABA using these software in studies relating GABA to pathology and healthy behaviour.