Sources of systematic error in proton density fat fraction (PDFF) quantification in the liver evaluated from magnitude images with different numbers of echoes

In conclusion, correction for known and expected biases in PDFF quantification in liver reduces the fitting error, decreases the dependence on the number of echoes and increases the accuracy. This retrospective analysis of liver MRI data from 463 subjects fitted the magnitude signal versus echo time from spoiled gradient echo imaging to estimate PDFF with different numbers of echoes (from 3 to 16). Monoexponential R2* decay and a multi‐peak fat spectrum were used, as well as additional corrections for non‐exponential decay (Gaussian), number of double bonds, R2* difference between water and fat, water frequency shift and noise bias. These corrections reduced the fitting error by 43.6 % and removed the dependence of PDFF and R2* on number of echoes.
Source: NMR in Biomedicine - Category: Radiology Authors: Tags: RESEARCH ARTICLE Source Type: research