Optical Analysis of Cirrhotic Liver by Near Infrared Time-Resolved Spectroscopy

Abstract

The severity of liver cirrhosis was related with the optical properties of liver tissue. Various grades of liver cirrhosis were produced in rats by intraperitoneal injection of thioacetamide (TAA) for different periods: 4 weeks, 8 weeks, 12 weeks, and 16 weeks. Optical properties of the liver, absorption coefficient (μa) and scattering coefficient (μs'), were measured by near-infrared time-resolved spectroscopy. Histological examination confirmed cirrhotic changes in the liver, which were more severe in rats with TAA administration for longer periods. The μa increased in 4- and 8-week rats, and then decreased in 12- and 16-week rats. The μa of blood-free liver decreased as liver cirrhosis progressed. The hemoglobin content in the liver calculated from the μa values increased in 4- and 8-week rats and decreased in 12- and 16-week rats. The μs' decreased in the cirrhotic liver, probably reflecting the decrease in the mitochondria content. It was shown that μa and μs' determination is useful to assess the severity of liver cirrhosis. © 1999 Society of Photo-Optical Instrumentation Engineers.