Early Detection of Nonalcoholic Fatty Liver Disease Utilizing a Novel QUS Method
Authors: Rowles Joe Lee , Miller Rita J , Han Aiguo , Wallig Matthew A , O'Brien William D , Erdman John W 
Published: November 2023

Non‐alcoholic fatty liver disease (NAFLD) is the most common liver disease in the Western world, affecting 20% of the population. If left untreated, NAFLD may progress into non‐alcoholic steatohepatitis (NASH), end‐stage liver disease or hepatocellular carcinoma. While conventional ultrasound and other imaging techniques can diagnose advanced stages of fatty liver and hepatic cirrhosis, existing techniques are imprecise and not able to detect early stage NAFLD which may lead to a delayed diagnosis of complications. The goal of this study was to utilize the novel non‐invasive quantitative ultrasound (QUS) method to detect and quantify hepatic fat content at stages of steatosis. In a pilot study, 8‐week‐old male C57BL/67 mice were divided into one of three different dietary groups (n=15/group): control (Con) or one of two different atherogenic diets (Ath or Ath‐Casein). The control diet was a casein‐based purified diet (17.2% fat kcal). The Ath diet was a standard chow diet supplemental cocoa butter, cholesterol and sodium cholate (32.4% fat kcal). The Ath‐casein diet was a modification of the control diet supplemented with cocoa butter, sodium cholate and cholesterol (32.3% fat kcal). The livers of each animal received weekly ultrasound scans starting prior to being placed onto one of the three diets until euthanasia. Each week, five animals were euthanized. At euthanasia, serum was collected and the liver was harvested. Half of the liver's lateral left lobe was stained with H&E (3‐μm section). Animals on the Ath‐Casein diet had significantly higher steatosis grading than animals on the Ath diet (P<0.05) and control diet (P<0.001). Lobular inflammation experienced a similar trend with inflammation being significantly increased in the Ath‐Casein (P<0.001) and Ath (P<0.01) diets compared to the control. Portal inflammation was statistically significant in both of the atherogenic diets compared to the control (P<.001). Interestingly, a significant effect of liver cell injury was only visible in the Ath‐Casein group (P<0.01 against Ath, and P<0.0001 against control). Overall, histology revealed that animals on either of the atherogenic diets were in a worse metabolic condition. In vivo and ex vivo ultrasound of the liver display increased attenuation and backscatter in both of the atherogenic diets compared to the control. Total hepatic lipids were evaluated by the Folch method and will be further compared to ultrasound for trends corresponding to steatosis and inflammation in the liver. Total serum and hepatic cholesterol will be measured. Additionally, serum alanine aminotransferase (ALT) and tumor necrosis factor α (TNFα) will be analyzed to determine liver damage and systemic inflammation. The development of a QUS method to identify early stages of NAFLD and NASH would provide the capability to noninvasively quantify and monitor liver condition and test methods for intervention.

Support or Funding Information

This work was supported by NIH R37EB002641