Objective To observe the value of micro flow imaging(MFI)for diagnosing closed liver trauma in pigs.Methods A self-made impactor was used to impact the liver of 15 healthy pigs under general anesthesia and establish pig models of closed liver trauma.Conventional ultrasound,MFI and contrast-enhanced ultrasound(CEUS)were used to observe the location,extent and degree of liver trauma.Afterwards,the pigs were executed and the livers were removed,and the liver lesions were observed.According gross pathological findings,the diagnostic efficacy of MFI was analyzed.Results Gross pathology showed a total of 29 liver traumas in 15 pigs.The accuracy rate of conventional ultrasound,MFI and CEUS for diagnosing liver trauma in pigs was 37.93％(11/29),82.76％(24/29)and 96.55％(28/29),respectively.Significant difference was found between conventional ultrasound and MFI,also between conventional ultrasound and CEUS(both P＜0.05),but not between MFI and CEUS(P＞0.05).MFI showed no obvious blood flow signal in more than half pig liver trauma sites,while showed"spring like"in 1 pig and scattered blood flow signals in 5 pigs.On CEUS,liver trauma sites in pigs present as low or no perfusion,while"jet like"contrast agent overflow from the liver was noticed in 1 pig and"spring like"contrast agent overflow in 5 pigs,forming liquid dark areas around the liver or in abdominal cavity.Conclusion MFI had certain value for diagnosing closed liver trauma in pigs,hence being comparable to CEUS.

Objective:To evaluate the safety and effectiveness of transjugular intrahepatic portosystemic shunt (TIPS) in hepatocellular carcinoma (HCC) patients with Vp4 portal vein tumor thrombus (PVTT).Methods:Data of 15 patients undergoing TIPS for HCC with Vp4 PVTT and portal hypertension (PTN) in Peking University First Hospital from July 2018 to February 2023 were retrospectively analyzed, including 14 males and 1 female, aged (61.5±11.1) years old, ranging from 40 to 78 years old. The success rate of TIPS, portal pressure gradient (PPG) before and after procedure, perioperative adverse effects and complications were recorded. The survival status of patients was followed up by telephone review after surgery. Kaplan-Meier method was used for survival analysis.Results:The procedure of TIPS was performed uneventfully in all patients, with a technical success rate of 100% (15/15). PPG before and after TIPS were (31.73±5.48) mmHg (1 mmHg=0.133 kPa) and (17.60±3.66) mmHg, respectively, and the difference was statistically significant ( P<0.001). No perioperative death, hepatic artery or bile duct injury, acute liver failure or other major complications occurred. Compared with the preoperative status, the performance status scores [0(0, 0) vs. 3(3, 3)] and Child-Pugh scores [6(5, 8) vs. 9(8, 10)] were lower in patients one month after TIPS (all P<0.05). The median survival time was 228 d. Kaplan-Meier curves showed that the cumulative survival rates at 3, 6, 12 and 24 months after TIPS were 100%, 64.3%, 32.7% and 8.2%, respectively. Conclusion:TIPS could be safe and effective for HCC with Vp4 PVTT and severe PTN.