Improved method for calculating hepatic steatosis using the hepatorenal index

Area of Science:

• Radiology
• Hepatology
• Medical Imaging Analysis

Background:

• Hepatorenal index (HRI) is a noninvasive tool for screening hepatic steatosis.
• Previous methods for HRI calculation required specialized software and multiple steps.

Purpose of the Study:

• To determine if HRI can be accurately calculated directly from Picture Archiving and Communication System (PACS) images.
• To assess the efficiency and speed of HRI calculation using PACS data.

Main Methods:

• Evaluated 99 patients from a previous study on hepatic steatosis.
• Calculated HRI using Digital Imaging and Communications in Medicine (DICOM) images from PACS and a region-of-interest tool.
• Compared PACS-derived HRI with values from specialized software and histologic estimates.

Main Results:

• A HRI cutoff of 1.34 demonstrated 92% sensitivity and 85% specificity for identifying hepatic steatosis (intracellular fat >5%).
• Substantial agreement (κ = 0.76) was found between PACS-derived HRI and histologic fat categorization.
• Mean HRI was 1.87 ± 0.6 for patients with steatosis and 1.14 ± 0.2 for those without.

Conclusions:

• Hepatorenal index calculation is accurate when performed directly on PACS using DICOM images.
• This method is quick and efficient, not requiring supplementary software.
• Direct PACS-based HRI calculation is a viable alternative for screening hepatic steatosis.