Neurodegeneration with brain iron accumulation: T2 relaxometry as a diagnostic tool

Abstract

The deposition of iron in the basal ganglia is na age-dependent physiological event. Increased iron has been shown in the central nervous system in many neurodegenerative diseases (such as Parkinson disease - PD, amyotrophic lateral sclerosis - ALS, Machado-Joseph disease - MJD and Friedreich's ataxia - FA). In this context, the use of Magnetic Resonances Imaging (MRI) through the analyses of transverse relaxation time (RT2) can be a powerful diagnostic tool for estimating in vivo iron deposits in central nervous system. This project aims to: a) compare the value or RT2 from healthy subjects obtained from previous study (from the same group of researchers) with the RT2 obtained from MRI images of patients with PD, ALS, MJD and FA; b) determine the estimated concentration of iron on the basal ganglia; c) determine sensibility and specificity of the RT2 evaluation on the determination of healthy subjects and patients. Methodology: T2 Multiecho images from 191 patients will be used for this study (32 AF, 48 MJD, 58 ALS, 53 PD). For each subject, four structures will be chosen on both sides from MRI 3T images (with T2 multiecho sequence): thalamus (T), globus pallidus (GP), substantia nigra (SN) and dentate nucleus (DN). For each structure, values of RT2 will be determined with the software Aftervoxel, by selecting 3 Regions of Interest (ROI) on 3 consecutive slices. The final RT2 value will be defined as the average of the 3 ROIs. For each disease, the values of RT2 will be compared with the control data (from the previous study) and a ROC curve will be created to determine the sensibility and specificity of the method. (AU)