To evaluate the diagnostic value of parameter micro flow imaging (P-MFI) in diagnosing ischemic-type biliary lesion (ITBL) after liver transplantation.

The clinical data of 25 liver transplantation recipients who were diagnosed with ITBL (ITBL group) during January 2015 and December 2017 in the Third Affiliated Hospital of Sun Yat-sen University were retrospectively analyzed, and 33 recipients without any complications during the same follow-up period were seclected as control group. Two doctors (doctor 1 and doctor 2) with 8 or 2 years of experience in abdominal ultrasound diagnosis were selected to perform contrast-enhanced ultrasonography and P-MFI diagnostic confidence scores in all cases by double-blind method. Group t-test was used to compare the age of the 2 groups, and the confidence scores of contrast-enhanced ultrasonography and P-MFI between doctor 1 and doctor 2. Chi-square test or Fisher′s exact probability method was used to compare the gender, method of biliary anastomosis cholangiostomy, primary disease, and the difference of P-MFI diagnostic confidence scores of doctor 1 and 2 between the 2 groups. Kappa test was used to evaluate the diagnostic consistency between doctor 1 and doctor 2. P<0.05 was considered statistically significant.

There was no significant difference in general data (age, sex, bile duct anastomosis and primary diseases) between the 2 groups (P all>0.05). The average editing time of P-MFI in ITBL and control group was (8.2±1.8) s and (6.8±1.9) s, which with statistical significance (t=-2.516, P<0.05). In the control group, the arteries were first showed in red; then the wall of bile duct and portal vein were clearly visualized, and the color of bile duct wall was mostly yellow-green or green (20 cases), partly mixed with green and blue (9 cases) or blue-purple (4 cases); finally, the wall of portal vein and hepatic parenchyma was visualized in blue and purple. In the ITBL group, arteries were first showed in red, portal vein wall was yellow or green; then the portal vein wall was visualized in yellow and green, the portal vein and hepatic parenchyma were visualized in blue or blue-purple; finally, the wall of bile duct was visualized which was unclear, with better color filling in green (8 cases), sporadic dotted green (4 cases), sparse dark blue or purple (10 cases), no color filling (3 cases). The average diagnostic confidence scores of contrast-enhanced ultrasonography and P-MFI of doctor 1 were(4.4±0.5)mark and (4.8±0.3) mark respectively, which with statistical significance (t=25.35, P<0.05). In the ITBL group, 22 cases (22/25) had higher P-MFI diagnostic confidence score than contrast-enhanced ultrasonography, while in the control group, 5 cases (5/33) had higher P-MFI diagnostic confidence score (χ²=50.088, P<0.05). The average diagnostic confidence scores of contrast-enhanced ultrasonography and P-MFI of doctor 2 were (4.2±0.6) mark and (4.7±0.5) mark respectively, which with statistical significance (t=22.52, P<0.05). In the ITBL group, 20 cases (20/25) had higher P-MFI diagnostic confidence score than contrast-enhanced ultrasonography, while in the control group, 6 cases (6/33) had higher P-MFI diagnostic confidence score (χ²=40.798, P<0.05). The two reviewers had good and general consistency in judging the ITBL group and the control group respectively (Kappa=0.706 and 0.455).

The P-MFI can visualized the blood perfusion of wall bile duct, hepatic vascular and liver parenchyma more intuitive and clearer, which can provide more information for the diagnosis of ITBL and enhance the diagnostic confidence.