Optimal threshold of controlled attenuation parameter with MRI-PDFF as the gold standard for the detection of hepatic steatosis

ABSTRACT

The optimal threshold of controlled attenuation parameter (CAP) for the detection of hepatic steatosis using both M and XL probe is unknown in nonalcoholic fatty liver disease (NAFLD). Magnetic resonance imaging proton-density-fat-fraction (MRI-PDFF) is an accurate and precise method to detect presence of hepatic steatosis and is better than CAP. Thus, the aim of this study was to evaluate the diagnostic accuracy and the optimal threshold of CAP for the detection of hepatic steatosis as defined by MRI-PDFF ≥ 5%. This cross-sectional study included 119 adults (59% women), prospectively recruited with and without NAFLD who underwent MRI-PDFF and CAP using either M probe or XL probe when indicated within a six-month period at the NAFLD Research Center, UCSD. Mean (±standard deviation) age and BMI were 52.4 (±15.2) years and 29.9 (±5.5) kg/m², respectively. The prevalence of NAFLD (MRI-PDFF≥5%) and MRI-PDFF≥ 10% was 70.6% and 47.1%, respectively. The area under the ROC (AUROC) of CAP for the detection of MRI-PDFF ≥ 5% was 0.80 (95%CI:0.70-0.90) at the cut-point of 288 dB/m and of MRI-PDFF ≥10% was 0.87 (95%CI:0.80-0.94) at the cut-point of 306 dB/m. When stratified by IQR of CAP, we observed that an IQR below median (30 dB/m) had a robust AUROC compared to IQR above median ([0.92, 95%CI:0.85-1.00] vs. [0.70, 95%CI:0.56-0.85], p-value=0.0117), and these differences were statistically and clinically significant.

Conclusion: The cut-point of CAP for presence of hepatic steatosis (MRI-PDFF ≥ 5%) was 288 dB/m. The diagnostic accuracy of CAP for the detection of hepatic steatosis is more reliable when IQR of CAP is <30 dB/m. These novel data have implications for clinical utility of CAP in the assessment of NAFLD. This article is protected by copyright. All rights reserved.

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