Evaluation value of contrast enhanced ultrasound quantitative parameters in ischemic-type biliary lesions after liver transplantation-a prospectively study.

Purpose: To explore the evaluation value of contrast enhanced ultrasound (CEUS) quantitative parameters in ischemic-type biliary lesions after liver transplantation to assist its early-diagnosis.

Methods: Patients who underwent liver transplantation and intravenous CEUS at Beijing Friendship Hospital, Capital Medical University from June 25, 2020 to December 28, 2022 and were diagnosed with Ischemic-type biliary lesions (ITBLs) by Magnetic Resonance Cholangiopancreatography (MRCP) or Endoscopic Retrograde Cholangiopancreatography (ERCP) or Percutaneous Transhepatic Cholangiography (PTC) were prospectively enrolled. SonoLiver software was used to quantitatively analyze the contrast images, transplanted livers with normal biliary tracts as the control group. SPSS 25.0 software was used to analyze the data.

Results: There was a total of 35 patients enrolled in the study, and 15 ITBLs and 30 normal biliary tract of transplanted livers, respectively. The dynamic vascular patterns (DVP) curve of the ITBLs group was negative wave, while the DVP curve of the normal biliary tract group was positive wave. Compared with the patients with normal biliary tract, the Maximum intensity (IMAX), Rise slope 50% (Rs50), Area under curve (AUC), Area under curve in Wash-in phase (WinAUC), Wash in Rate (WinR), Rise slope 10-90% (Rs1090), and Wash out Rate (WouR) of the ITBLs group were lower, while the Fall slope (Fs50) was higher. There was no significant difference in Rise time (RT), Time to Peak (TTP), Fall half time (FHT), Mean transit time (mTT), Fall time (FT), WioAUC ((WioAUC = WinAUC + WouAUC)), and Area under curve in Wash-out phase (WouAUC) between the two groups (P > 0.05). The ROC curve results showed that Fs50 > -2.64 was the cutoff value for predicting ITBLs, with an area under the curve of 0.816 (95%CI: 0.683-0.949), and a sensitivity and specificity of 0.846 and 0.607; Rs50 < 7.08, AUC < 39761.7050, WinR < 101.7 and WouR < 474.52 were the cutoff values ​​for predicting ITBLs, with areas under the curve of 0.853 (95%CI: 0.728-0.979), 0.911 (95%CI: 0.783-1.000), 0.756 (95%CI: 0.615-0.896) and 0.700 (95%CI: 0.536-0.864).

Conclusion: The quantitative parameters of CEUS imaging, such as IMAX, Rs50, AUC, WinAUC, WinR, Rs1090, WouR, and Fs50, are helpful in predicting ITBLs and improving the reproducibility of diagnosis. The threshold of these quantitative parameters will aid in the early diagnosis of ischemic-type biliary lesions after liver transplantation.