Detection of hepatic hemodynamics in normal rhesus monkeys using high-frequency ultrasound

The rhesus monkey liver disease model provides useful information for hepatic research, as studies of hepatic hemodynamics in humans are rare. A 3-9 MHz high-frequency linear transducer (iU22, Philips Medical Systems, Royal Philips Electronics, The Netherlands) was used to obtain ultrasonograms of the livers of 28 normal rhesus monkeys (16 males, 12 females). Diameters of the portal vein and proper hepatic artery; maximum velocity of the portal vein; and peak-systolic and end-diastolic velocity and resistive index of the proper hepatic artery were also assessed. The portal vein and proper hepatic artery were 0.584 ± 0.123 and 0.151 ± 0.052 cm in diameter, respectively. The maximum velocity of the portal vein was 40.2 ± 13.7 cm/s. Peak systolic velocity and resistive index of the proper hepatic artery were 72.2 ± 25.4 cm/s and 0.67 ± 0.10, respectively. We found that high-frequency Doppler ultrasonography can be used to obtain clear portal vein and proper hepatic artery ultrasonograms and to measure the hemodynamic parameters of the portal vein and proper hepatic artery in rhesus monkeys. It is thus an effective method for studying changes in hepatic hemodynamics and has interesting technical and therapeutic implications. Our results provide useful information and establish normal reference values for future studies of adult healthy rhesus monkeys.