Label-free metabolic imaging of non-alcoholic-fatty-liver-disease (NAFLD) liver by volumetric dynamic optical coherence tomography

TL;DR

This study demonstrates a label-free, volumetric metabolic imaging technique using dynamic optical coherence tomography to visualize and assess liver abnormalities in a mouse model of non-alcoholic fatty liver disease (NAFLD).

Contribution

The paper introduces a novel application of dynamic OCT with LIV analysis for three-dimensional metabolic imaging of NAFLD liver tissue without labels.

Findings

Visualized lipid droplet accumulation and inflammation in 3D.

Identified distinct metabolic structures in normal and diseased liver.

Demonstrated potential for non-invasive NAFLD assessment.

Abstract

Label-free metabolic imaging of non-alcoholic fatty liver disease (NAFLD) mouse liver is demonstrated ex vivo by dynamic optical coherence tomography (OCT). The NAFLD mouse is a methionine choline-deficient (MCD)-diet model, and two mice fed MCD diet for 1 and 2 weeks are involved in addition to a normal-diet mouse. The dynamic OCT is based on repeating raster scan and logarithmic intensity variance (LIV) analysis which enables volumetric metabolic imaging with a standard-speed (50,000 A-lines/s) OCT system. Metabolic domains associated with lipid droplet accumulation and inflammation are clearly visualized three-dimensionally. Particularly, the normal-diet liver exhibits highly metabolic vessel-like structures of peri-vascular hepatic zones. The 1-week MCD-diet liver shows ring-shaped highly metabolic structures formed with lipid droplets. The 2-week MCD-diet liver exhibits fragmented vessel-like structures associated with inflammation. These results imply that volumetric LIV imaging is useful for visualizing and assessing NAFLD abnormalities.