Quantitative Assessment of Hepatic Fat of Intact Liver Tissues with Coherent Anti-Stokes Raman Scattering Microscopy

• Published in: Analytical chemistry (Washington) Vol. 81; no. 4; pp. 1496 - 1504
• Main Authors: Wu, Yao-Ming, Chen, Hung-Che, Chang, Wei-Tien, Jhan, Jhen-Wei, Lin, Hung-Lung, Liau, Ian
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15.02.2009
• Subjects: Analytical biochemistry: general aspects, technics, instrumentation; Analytical chemistry; Analytical, structural and metabolic biochemistry; Animals; Biochemistry; Biological and medical sciences; Chemistry; Diet; Exact sciences and technology; Female; Fluorescence; Fundamental and applied biological sciences. Psychology; Indicators and Reagents - chemistry; Lipid Metabolism; Lipids; Lipids - analysis; Lipids - chemistry; Liver; Liver - chemistry; Liver - cytology; Liver - drug effects; Microscopy; Rats; Scattering; Spectrometric and optical methods; Spectrum Analysis, Raman; Tissues; Biochemical analysis; Chemical analysis; Liver; Environmental factor; Lipids; Anti Stokes line; Droplet; Tissue; Image analysis; Sample preparation; Raman scattering; Imaging; Fat; Critical study; Raman spectrometry; Content analysis
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac8026838

A fatty liver might progress from being a benign fatty liver, to steatohepatitis, cirrhosis, or even hepatocellular carcinoma. The great prevalence and severe outcome have warranted much investigation of the pathology and the development of effective therapies, which involve animal studies requiring critical evaluation of the hepatic fatty change. Histological examination and wet chemical analysis of liver biopsy specimens are generally employed for this purpose despite numerous procedures being involved. Using coherent anti-Stokes Raman scattering (CARS) microscopy, we have demonstrated the specific imaging of fat droplets in intact liver tissues and extracted the hepatic fat content through image analysis while eliminating laborious procedures required by traditional histopathological examination. The content of hepatic fat measured with CARS imaging was correlated strongly with that determined by biochemical analysis (R 2 = 0.89) over a pathologically significant range of the hepatic fat (from 2% to 20% of the total mass of tissue). Our work validates the quantitative assessment of fat in intact tissue through the use of CARS microscopy. When combined with the increasingly diverse animal models of diseases related to metabolic disorders of lipids, our approach is extensible to enable acquiring important insight into the genetic, environmental, and dietary factors affecting the uptake and accumulation of fat within tissues.