Evaluation of cerebral perfusion by contrast-enhanced ultrasound at low mechanical index in cerebral ischemia rat model.

BACKGROUND

No data is available for brain low mechanical index (low-MI) contrast-enhanced ultrasound (CEUS). This study aimed to assess low-MI CEUS for cerebral ischemia in rats.

METHODS

Twenty adult Wistar rats were divided to the brain ischemia (N.=12) and sham (N.=8) groups. A Logiq E9 (GE; ML6-15 probe) was used. Bolus injection of SonoVue (Bracco) at 3.6 mL/kg was performed. Cerebral perfusion was evaluated using time to peak (TTP) and area under the curve (AUC) of time-intensity curves (TIC).

RESULTS

There was a decrease in peak systolic BFV of anterior cerebral and middle cerebral arteries in ischemic rats and a sharp increase in peak systolic BFV of basilar artery compared with sham rats (all P<0.01). Microbubble enhancement occurred in the Willis circle, followed by diencephalon and telencephalon. The AUC and TTP of the region of interest at telencephalon were significantly different between the two groups; in addition, the differences with the diencephalon were also significant (all P<0.01). There were differences in AUC and TTP between the telencephalon and diencephalon of the same group (all P<0.05).

CONCLUSIONS

Real-time low-MI CEUS could sensitively demonstrate dynamic microbubble enhancement in brain tissues and allows semi-quantitative assessment of cerebral perfusion after ischemic brain injury using TIC.