【摘要】 目的应用对比超声(contrast enhanced ultrasound,CEU)定量评价不同通气状态对脑组织血流灌注的影响。方法健康杂种犬6条,左侧顶骨开窗。调节呼吸机参数造成犬高或低通气状态后行声学造影。以颈总动脉血流为对照,评价CEU定量局部脑组织血流量(cerebral blood flow,CBF)的可靠性;并进一步比较不同通气状态下CEU参数的变化趋势。结果CEU估测CBF值与颈总动脉血流量具有良好的相关性。低通气状态较基础状态CBF明显增加,而高通气状态则明显减少。CBF变化是由微循环血管容积和血流速度双向调节引起的。结论CEU可以准确定量评估CBF,并有望用于脑组织血流变化的病理生理研究。更多还原

【Abstract】 Objective To evaluate the changes of cerebral blood flow (CBF) with real-time contrast enhanced ultrasound (CEU) at different ventilation status.Methods Cerebral perfusion was assessed in 6 dogs through a craniotomy with CEU at baseline,during hyperventilation and hypoventilation.Cerebral microvascular blood volume (A),microbubble velocity (as well as red blood cell velocity,β),and blood flow (A×β) were calculated from time-versus-acoustic intensity relations.Blood flow of common carotid arteries were measured by ultrasonic flow probes.Results Compared with the baseline,the value of A,β and A×β were significantly decreased and increased at hyperventilation and hypoventilation respectively.Conclusions Changes in both cerebral microvascular blood volume (A) and red blood cell velocity (β)can be accurately assessed with CEU.Alterations in CEU-derived CBF were attributable to changes in both microvascular blood volume and red blood cell velocity.更多还原