Evaluation of minimum-to-severe global and macrovesicular steatosis in human liver specimens: a portable ambient light-compatible spectroscopic probe
Authors: Guo Hao , Stueck Ashley E. , Doppenberg Jason B. , Chae Yun Suk , Tikhomirov Alexey B. , Zeng Haishan , Engelse Marten A. , Gala-Lopez Boris L. , Mahadevan-Jansen Anita , Alwayn Ian P.J. , Locke Andrea K. , Hewitt Kevin C. 
Published: December 2023

Background & AimsHepatic steatosis (HS), particularly macrovesicular steatosis (MaS), influences transplant outcomes. Accurate assessment of MaS is crucial for graft selection. While traditional assessment methods have limitations, non-invasive spectroscopic techniques like Raman and reflectance spectroscopy offer promise. This study aimed to evaluate the efficacy of a portable ambient light-compatible spectroscopic system in assessing global HS and MaS in human liver specimens.MethodsA two-stage approach was employed on thawed snap-frozen human liver specimens under ambient room light: biochemical validation involving a comparison of fat content from Raman and reflectance intensities with triglyceride (TG) quantifications and histopathological validation, contrasting Raman-derived fat content with evaluations by an expert pathologist and an artificial intelligence (AI) algorithm. Raman and reflectance intensities were combined to discern significant (≥10%) discrepancies in global HS and MaS.ResultsThe initial set of 16 specimens showed a positive correlation between Raman and reflectance-derived fat content and TG quantifications. The Raman system effectively differentiated minimum-to-severe global and macrovesicular steatosis in the subsequent 66 specimens. A dual-variable prediction algorithm, was developed, effectively classifying significant discrepancies (>10%) between AI-estimated global HS and pathologist-estimated MaS.ConclusionOur study established the viability and reliability of a portable spectroscopic system for non-invasive HS and MaS assessment in human liver specimens. The compatibility with ambient light conditions and the ability to address limitations of previous methods marks a significant advancement in this field. By offering promising differentiation between global HS and MaS, our system introduces an innovative approach to real-time and quantitative donor HS assessments. The proposed method holds promise of refining donor liver assessment during liver recovery and ultimately elevating transplantation outcomes.Lay SummaryThis research explored a portable ambient light-compatible spectroscopic probe to non-invasively assess global and macrovesicular steatosis in human liver specimens. Our findings suggest that this method can be a reliable tool to aid surgeons’ decision-making on a liver’s suitability for transplantation.Graphic AbstractHighlightsWe introduced a portable ambient light-compatible spectroscopic probe which could non-invasively analyze Raman scattering and reflectance of human liver specimens.Both biochemical and histopathological approaches were applied to validate the spectroscopic probe.Histopathological evaluation covered minimum-to-severe global and macrovesicular steatosis, surpassing previous spectroscopic studies.A dual-variable prediction for precise differentiation between global and macrovesicular steatosis offers the potential for enhanced, real-time, and quantitative liver assessments in clinical settings.