Quantitative chemical shift-encoded MRI is an accurate method to quantify hepatic steatosis

Abstract

Purpose To compare the accuracy of liver fat quantification using a three-echo chemical shift-encoded magnetic resonance imaging (MRI) technique without and with correction for confounders with spectroscopy (MRS) as the reference standard. Materials and Methods Fifty patients (23 women, mean age 56.6 ± 13.2 years) with fatty liver disease were enrolled. Patients underwent T2-corrected single-voxel MRS and a three-echo chemical shift-encoded gradient echo (GRE) sequence at 3.0T. MRI fat fraction (FF) was calculated without and with T2* and T1 correction and multispectral modeling of fat and compared with MRS-FF using linear regression. Results The spectroscopic range of liver fat was 0.11%–38.7%. Excellent correlation between MRS-FF and MRI-FF was observed when using T2* correction (R2=0.96). With use of T2* correction alone, the slope was significantly different from 1 (1.16 ± 0.03, P < 0.001) and the intercept was different from 0 (1.14% ± 0.50%, P < 0.023). This slope was significantly different than 1.0 when no T1 correction was used (P=0.001). When T2*, T1, and spectral complexity of fat were addressed, the results showed equivalence between fat quantification using MRI and MRS (slope: 1.02 ± 0.03, P=0.528; intercept: 0.26% ± 0.46%, P=0.572). Conclusion Complex three-echo chemical shift-encoded MRI is equivalent to MRS for quantifying liver fat, but only with correction for T2* decay and T1 recovery and use of spectral modeling of fat. This is necessary because T2* decay, T1 recovery, and multispectral complexity of fat are processes which may otherwise bias the measurements.

Quantification of renal steatosis in type II diabetes mellitus using dixon‐based MRI

“…A major strength of this study is the use of proton-density FF, an existing MR biomarker of steatosis, extensively validated in the liver in the setting of NAFLD (34-36). The Dixon-based pulse sequence used, mDixon-Quant, is commercially available and is approved by the Food and Drug Administration for the liver triglyceride quantification by MRI.…”

Intra- and inter-examination repeatability of magnetic resonance spectroscopy, magnitude-based MRI, and complex-based MRI for estimation of hepatic proton density fat fraction in overweight and obese children and adults

“…Intra-examination repeatability has been reported for MRI-M and MRS at both 1.5 and 3T [8, 9, 12, 16], and inter-examination repeatability has been demonstrated for MRI-M (3T) [21], MRI-C (1.5T) [26], and MRS (1.5T) [26]. MR-based estimation of PDFF has shown to be equivalent with MRI-C and MRI-M across 1.5 and 3T [12], and across different platforms [15].…”

Effect of Weight Loss on Magnetic Resonance Imaging Estimation of Liver Fat and Volume in Patients With Nonalcoholic Steatohepatitis

“…[27, 30, 31, 35–38] It acquires multiple echoes at different echo times with fat and water signals nominally in phase or out of phase with each other and applies an algorithm to generate a PDFF parametric map depicting fat quantity and distribution throughout the liver. This method has been shown to reliably measure liver fat content when compared to other magnetic resonance techniques and histology-determined steatosis, and it is sensitive in detecting changes in liver fat content [31, 36, 39] . In order to estimate PDFF across the entire liver, 3 regions of interest (ROIs) 300mm 2 to 400mm 2 in area were placed in each of the nine liver segments on the PDFF parametric maps (figure 1).…”