Comparison between ROI-based and volumetric measurements in quantifying heterogeneity of liver stiffness using MR elastography
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This study was conducted to quantify the heterogeneity of liver stiffness (LS) on MR elastography (MRE) by comparing ROI-based and volumetric measurements.
LS was measured by ROI-based and volumetric segmentation of the liver parenchyma. Mean LS (MLS) was calculated and used to assign stages of fibrosis. Volumetric measurements of stiffness maps were used to determine the percentage of liver volume above/below MLS and presence of LS heterogeneity. Heterogeneous stiffness was defined when the first and second most predominant stages were more than one category apart. MLS values by each method were compared using the Wilcoxon signed-rank test.
We included 128 patients with suspected liver fibrosis (mean age 54.4 ± 14.8 years). MLS was 2.7 ± 1.0 kPa for ROI measurements and 2.6 ± 0.9 kPa for the volumetric method (p = 0.001). Of 59 patients with normal stage (F0), 31 patients (52.5%) had > 20% of liver volume with abnormal LS (F1–F4). Heterogeneous LS was reported in 18 patients (14%).
MLS measurement may not represent the entire spectrum of hepatic fibrosis. Volumetric segmentation may potentially improve the detection of heterogeneous fibrosis and the accuracy of LS measurement.
• Heterogeneity of hepatic fibrosis may occur in patients with chronic liver disease.
• MR elastography is used to assess hepatic fibrosis by measuring liver stiffness.
• Measuring liver stiffness by the ROI method and reporting a mean value may fail to detect heterogeneity of hepatic fibrosis. Volumetric assessment of liver stiffness by MR elastography may detect heterogeneity of parenchymal involvement.
KeywordsMagnetic resonance elastography Elastography Liver cirrhosis Fibrosis Elasticity imaging techniques
Chronic liver diseases
- MLS stage
Stage of fibrosis assigned to each patient based on mean liver stiffness value of ROIs
Mean liver stiffness
Magnetic resonance elastography
ROI-based segmentation for liver stiffness measurement
Volumetric segmentation for liver stiffness measurement
The authors state that this work has not received any funding.
Compliance with ethical standards
The scientific guarantor of this publication is Ihab R Kamel, M.D., Ph.D.
Conflict of interest
The authors declare that they have no conflict of interest.
Statistics and biometry
No complex statistical methods were necessary for this paper.
Written informed consent was waived by the Institutional Review Board.
Institutional Review Board approval was obtained.
• Cross-sectional study diagnostic
• Performed at one institution
- 34.Dzyubak B, Venkatesh SK, Glaser K et al (2013) Stable automated segmentation of liver MR elastography images for clinical stiffness measurement. Proc SPIE Int Soc Opt Eng, 8672Google Scholar