Measurement Precision of Contrast Agent with R2* (Magnitude) and Quantitative Susceptibility Mapping (Phase)

Hongchen Wang¹, Xavier Matre¹, Jean-Pierre Ruaud¹, Luc Darrasse¹, Ludovic De Rochefort²

Apparent transverse relaxation rate R2* and magnetic susceptibility χ are distinct measurable parameters that can be used to quantify paramagnetic and superparamagnetic materials. R2* mapping requires several echoes times in a gradient-echo scan and is based on the analysis of signal amplitude decrease. Magnetic Susceptibility mapping uses field mapping that can be measured from the same multi-echo dataset using phase images. Here, phantom experiments are done to compare the precision of R2* and susceptibility methods for quantifying contrast agent concentration.