Modeling of T2* Decay in Water/fat Imaging: Comparison of One-Decay and Two-Decay Models

Diego Hernando¹, Zhi-Pei Liang¹, Peter Kellman²

In quantitative water/fat imaging, modeling the T2* decay of the signal is necessary in order to avoid significant bias. A two-decay model with separate decay rates for water and fat has recently been proposed as an alternative to the one-decay model where water and fat share a common decay rate. Even though the two-decay model is more realistic, it suffers from increased noise sensitivity with respect to the one-decay model. In this work, we analyze quantitatively this tradeoff between bias and standard deviation using simulation, phantom and in vivo data. Our results show that a one-decay model is preferable for a clinically relevant range of fat fractions and SNRs.