Quantitative MRI of normal brachial plexus and parameters correlations with demographic and anthropometric data.

BACKGROUND: Conventional MRI allows only subjective qualitative images evaluation. There are quantitative approaches which let to make our evaluation more objective and obtain extra data for diagnostic and differential diagnostic of diseases, previously available for brain and joints imaging. A number of technical innovations nowadays let us use it also for peripheral nerves. AIM: evaluation of possibility to use quantitative MRI techniques for brachial plexus imaging, postprocessing algorithm creation and presentation of normal values distribution along with their correlations with demographic and anthropometric parameters investigation. METHODS: MRI, demographic and anthropometric data were acquired from ten healthy subjects. 3T MRI scanner was used to obtain T2-relaxometry parameters and magnetization transfer ratio of brachial plexus roots. Postprocessing was performed using MATLAB, ROIs were placed manually. Roots thickness was also measured on coronal STIR images. Statistical analysis was performed using Statistica software. RESULTS: Quantitative parameters (T2apparent time (T2app), proton density (ρ), magnetization transfer ratio (MTR)) were obtained from C5-Th1 roots of all healthy subjects. Thickness gradient was demonstrated with maximum thickness at C7 level. Spearman correlation analysis showed significant (p0,05) positive correlations between T2app and age (Spearman ro =0,36), significant negative correlations between nerve diameter and T2app (ro=-0,23), height and both T2app (ro=-0,5) and proton density (ro=-0,57). CONCLUSION: Received data demonstrated the possibility to use quantitative MRI techniques for brachial plexus evaluation. Revealed correlations between T2app and age and height evidence to count for these parameters while evaluating quantitative MRI data obtained from brachial plexus.