To investigate the value of contrast-enhanced ultrasound (CEUS) in evaluation of the protective effect of edaravone injection in rabbit skeletal muscle ischemia-reperfusion injury.

Thirty healthy New Zealand white rabbits were established a model of skeletal muscle ischemia-reperfusion injury in left hind limb and randomly divided into the experimental group and control group. Edaravone was injected with the dose of 1.5 mg/kg at the time of 30 minutes before reperfusion in the experimental group, the control group were given an equal volume of physiological saline. Blood samples were collected respectively at the times of pre-ischemia, post-ischemia and 24 hours after reperfusion for detecting creatine kinase(CK), lactic dehydrogenase(LDH), and CEUS parameters such as peak intensity(PI), time to peak(TTP) and area under the curve(AUC) were measured at the same time. Pathological examination was carried out after the rabbits were sacrificed.

①Serological tests: compared to before the blocking of blood supply, the content of CK and LDH after the blocking were significantly increased(P<0.01); compared to before or after the blocking, the content of CK and LDH at the time of 24 hours after reperfusion in the two groups were increased, and was lower in the experimental group than the control group. ②CEUS: compared to before the blocking, PI, TTP and AUC in each group were significantly increased after the blocking and at the time of 24 hours after reperfusion(P<0.01); compared to those in the control group, PI and AUC in the experimental group were decreased at the time of 24 hours after reperfusion, but there was no significant difference in TTP(P>0.05). ③Correlation analysis: there was a good correlation between PI, AUC and CK, LDH(r=0.87, 0.81, 0.86, and 0.80, respectively). ④Pathological analysis: muscle fibers were swelling with no stripes, partial fractures and interstitial edema and a large amount of inflammatory cells were infiltrated in the control group, while muscle fibers were almost normal with a small amount of inflammatory cells infiltrated in the experimental group.

Edaravone injection before reperfusion can obviously improve rabbit skeletal muscle ischemia-reperfusion injury, and CEUS can be used to observe these changes directly and effectively.

Contrast-enhanced ultrasound; Ischemia-reperfusion injury; Edaravone