A comparative study of liver blood flow using 133Xenon clearance and electromagnetic flowmeter measurements

Recent work has shown that the slow components of the multiexponential clearance of 133Xenon from the liver are generated by radioactive gas in the stomach and intestines, and that the true intraphepatic clearance is monoexponential (Mackenzie et al., 1976). In the present study, liver blood flow calculated from the fast component of the 133Xenon clearance curve was compared with the total hepatic flow recorded with electromagnetic flow probes on the portal vein and hepatic artery in 8 dogs. Injections of isotope were made intoe the portal vein, and the clearance curves treated simply as biexponentials. A total of 50 pairs of blood flow measurements with the two techniques was obtained over a range of values from 80 to 1400 ml/min, and a close correlation found between them (r = 0.91). This result shows that when the clearance rate of the fast component is used for the flow calculation, the 133Xenon clearance technique provides an accurate measure of liver blood flow.