The effect of measurement depth and technical considerations in performing liver attenuation imaging

Background and Aims

Clinical unmet need in managing nonalcoholic fatty liver disease (NAFLD), a common liver disorder affecting 25–30% of American adults is to develop noninvasive and robust biomarkers.

Methods

We re-measured liver AC by placing a region of interest (ROI, 3 cm tall and 3 cm wide) at 4.5 cm, 6 cm, and 7.5 cm from the skin and a large ROI (6.0 cm tall and 7.3 cm wide) on pre-recorded ATI images from 117 participants screened for NAFLD. The difference in AC value at variable ROI depths was tested using one-way ANOVA (analysis of variance). Diagnostic performances of AC at variable depths in determining hepatic steatosis were examined by area under receiver operating characteristic curve (AUC) using MRI-proton density fat fraction (MRI-PDFF) as reference and were compared using paired-sample Z-test.

Results

Based on MRI-PDFF, 117 livers were divided to 27 normal livers (MRI-PDFF < 5%) or 90 steatotic livers (MRI-PDFF ≥ 5%). Differences in AUC and AC value at variable depths and size were statistically significant (p < 0.01). The best performance for determining hepatic steatosis was the AC measured at 6 cm from the skin (AUC = 0.92). Sources of errors in performing ATI included reverberation, blank color region, and acoustic shadowing within the measurement ROI.

Conclusions

ROI depth significantly influences liver AC estimation. The best ROI depth to measure liver AC in patients with BMI ≥ 30 may be at a depth of 6 cm from the skin. Technical considerations should be taken in performing liver ATI.

Full text

https://www.xiahepublishing.com/2994-8754/JTG-2023-00047

The study was recently published in the Journal of Translational Gastroenterology.

Journal of Translational Gastroenterology (JTG) dedicates to improving clinical diagnosis and treatment, advancing understanding of the molecular mechanisms, and promoting translation from bench to bedside of gastrointestinal, hepatobiliary, and pancreatic diseases. The aim of JTG is to provide a forum for the exchange of ideas and concepts on basic, translational, and clinical aspects of gastroenterology, and promote cross-disciplinary research and collaboration.

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