RESUMEN

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.