Optimal cutoff value for assessing changes in intrahepatic fat amount by using the controlled attenuation parameter...

Area of Science:

• Hepatology
• Medical Imaging
• Non-invasive Diagnostics

Background:

• Controlled Attenuation Parameter (CAP) effectively assesses liver fat cross-sectionally.
• Longitudinal studies evaluating CAP's ability to track changes in liver fat are lacking.

Purpose of the Study:

• To investigate the correlation between changes in CAP and magnetic resonance imaging-estimated proton density fat fraction (MR PDFF) over time.
• To assess the reliability of CAP in monitoring treatment response in nonalcoholic fatty liver disease (NAFLD).

Main Methods:

• Sixty-five NAFLD patients underwent serial MR PDFF and CAP measurements at baseline and 3 months.
• Correlation analysis was performed on baseline values and changes over time.
• Receiver operating characteristic (ROC) curve analysis identified optimal cutoff values for CAP change.

Main Results:

• Strong baseline correlation between CAP and MR PDFF (r=0.66, P<.001).
• Weak correlation between changes in CAP and MR PDFF over 3 months (r=0.37, P=.005).
• An optimal cutoff of 38 dB/m for CAP change showed limited accuracy (46%) in detecting significant fat percentage changes (>1%).

Conclusions:

• While CAP correlates with liver fat cross-sectionally, its utility in tracking longitudinal changes in NAFLD patients is limited.
• Careful interpretation of steatosis changes based on CAP is advised, especially for changes below 38 dB/m.
• Further research may be needed to refine non-invasive methods for monitoring NAFLD treatment response.