Abstract: Objective   To explore the clinical value of Tardus Parvus waveform and contrast-enhanced ultrasound (CEUS) microperfusion quantitative technique in hepatic artery stenosis after liver transplantation.   Methods　Sixty cases of liver transplantation patients of hepatic artery doppler ultrasound, ultrasonic imaging and CTA/DSA examination data were collected separately. The systolic peak of hepatic artery doppler ultrasound blood flow velocity (PSV), end-diastolic velocity (EDV), resistance index (RI), acceleration time (SAT) were recorded. Tardus Parvus waveform of the diagnostic criteria were RI < 0.5 and SAT > 0.8 s. Contrast-enhanced ultrasound was used to record quantitative parameters such as marginal region of liver and central region basic identity (BI), arrival time (AT), peak intensity (PI), time to peak (TTP), absolute value of difference in real enhancement identity (REI) between the central region and the marginal region. Patients were divided into two groups according to the standard of hepatic artery stenosis rate ≥ 50% diagnosed by CTA or DSA: a hepatic artery stenosis group and a non-stenosis group.  Results   Doppler ultrasound in the hepatic artery stenosis group showed positive Tardus Parvus waveform (P<0.05). Compared with the non-stenosis group, absolute value of difference in REI between the central region and the marginal region reduced (P<0.05), and TTP in the central region prolonged (P<0.05).  Conclusions   Tardus Parvus waveform and contrast-enhanced microperfusion quantitative technique have a certain value in the diagnosis of hepatic artery stenosis after liver transplantation. 

Key words: Liver transplantation, 　Hepatic artery stenosis, 　Tardus Parvus waveform, 　Quantitative technique of CEUS microperfusion