Date: 2018 May 30
Time: Noon - 1PM
Location: 1-075 RTF
Abstract:
Multiple Sclerosis (MS) is a progressive autoimmune and neurodegenerative disease of the Central Nervous System that results in demyelination and neuronal/axonal loss. Along with clinical evaluation, Magnetic Resonance Imaging (MRI) is the gold standard modality for diagnosing and monitoring MS, which has been conventionally carried out using T1 and T2-weighted pulse sequences. Gradient-echo T2*-weighted has been recently demonstrated as a sensitive predictor of MS disability and cognitive decline; however, more research is needed to implement quantitative gradient-echo (qGE) based techniques into clinical practice and drug trials. The purpose of this thesis was to develop technical MRI innovations and study research applications to further the field of qGE MRI of MS. The main clinical hypothesis was that qGE MRI methods may serve as a biomarker of disease progression in MS. This hypothesis was tested in one cross-sectional study and two longitudinal studies of MS subjects compared to age-matched controls, where we related MRI findings to clinical outcomes. We investigate the limitations of using Quantitative Susceptibility (QS) mapping for analyzing lesions in MS, and demonstrate that further work is needed to utilize QS for analyzing QS lesion contrast. We also explore the use of field-of-view (FOV) restriction to accelerate MRI acquisitions used for QS mapping, and demonstrate the sensitivity of QS accuracy to FOV changes. Using combined R2* and QS mapping, we present novel qGE cross-sectional and longitudinal analysis techniques, and demonstrate the correlation of qGE to clinical measures. Thus, we demonstrate that qGE is indeed a valuable tool that may be used for monitoring MS disease progression.