Medical Physics Seminar – Monday, February 25, 2013
Signal Modeling for MRI-based Fat and Iron Quantification
Deb Horng (student of Dr. Scott Reeder)
Research Assistant, Department of Medical Physics, UW-School of Medicine & Public Health, Madison, WI - USA –
Magnetic Resonance Imaging (MRI) is very sensitive to the presence of both fat and iron. In “gradient-echo†MRI acquisitions, the fat introduces additional signal oscillations, since fat signal resonates at a frequency slightly slower than that of water, and the MRI scanner is usually tuned to the water frequency. Iron accumulation introduces accelerated signal decay (T2* relaxation). This signal dependence on fat and iron can be exploited for multiple clinical applications: for instance, in liver imaging it can be used to simultaneously assess fatty liver and iron overload. However, accurate signal modeling is required for these measurements. In this talk, I will discuss the T2* relaxation behavior of water and fat signals with and without liver iron, and its implications for the development of MRI-based quantitative imaging biomarkers.