Objective: To investigate the effect of increased cardiac output induced by dobutamine on cerebral blood flow (CBF) in healthy volunteers using magnetic resonance 3D-pseudo-continuous arterial spin labeling technology. Methods: A prospective study was conducted on 48 healthy volunteers recruited by handy sampling from June 2021 to January 2022. Physiological parameters before (at rest state) and after (under stress state) dobutamine-induced increase in cardiac output were analyzed. Quantitative CBF maps were generated by using arterial spin labeling difference imaging and proton density weighted reference image processing, and CBF changes under the rest and stress states were compared. Multivariable logistic regression model was used to analyze factors associated with reduced CBF. Results: A total of 48 subjects were included, with an age [M (Q1, Q3)] of 25.0 (24.0, 28.0) years, including 43 men and 5 women. Compared with the rest state, the CBF in the anterior cerebral artery [(36.2±6.9) vs (34.5±6.5) ml·(100 g)-1·min-1, P=0.006] and the middle cerebral artery perfusion area [(35.8±6.5) vs (34.1±6.4) ml·(100 g)-1·min-1, P=0.006] decreased under the stress state, however there was no statistically significant change in CBF in the posterior cerebral artery and the vertebral-basilar artery perfusion area (all P>0.05). Logistic regression analysis showed that the decrease in CBF in the anterior cerebral artery and middle cerebral artery supply regions during the stress state were correlated with an increase in diastolic blood pressure [OR (95%CI): 0.887 (0.796-0.989) and 0.895 (0.805-0.994), both P<0.05]. Conclusions: Dobutamine-induced increase in cardiac output leads to a decrease in CBF in anterior cerebral circulation but has no effect on posterior circulation. The increase in diastolic blood pressure is associated with decreased CBF under the stress state. Changes in CBF should be considered in the context of increased cardiac output.
目的： 探讨基于MRI 3D-伪连续动脉自旋标记技术下多巴酚丁胺诱导心输出量增加后对健康志愿者脑血流量（CBF）的影响。 方法： 前瞻性纳入2021年6月至2022年1月通过广告招募获取的健康志愿者48名为研究对象，分析其在多巴酚丁胺诱导心输出量增加前（静息状态）、后（负荷状态）生理参数变化，使用动脉自旋标记差异图像和质子密度加权参考图像处理生成定量CBF图，比较静息状态和负荷状态下CBF变化。采用多因素logistic回归模型分析CBF降低的相关因素。 结果： 48名受试者的年龄［M（Q1，Q3）］为25.0（24.0，28.0）岁，男43名，女5名。与静息状态相比，多巴酚丁胺负荷状态下大脑前动脉供血区［（36.2±6.9）比（34.5±6.5）ml·（100 g）-1·min-1，P=0.006］和大脑中动脉供血区［（35.8±6.5）比（34.1±6.4）ml·（100 g）-1·min-1，P=0.006］CBF减低，而大脑后动脉和椎-基底动脉供血区CBF差异无统计学意义（P>0.05）。负荷状态下舒张压升高是大脑前、中动脉供血区CBF降低的相关因素，OR值（95%CI）分别为0.887（0.796~0.989）、0.895（0.805~0.994），均P<0.05。 结论： 多巴酚丁胺诱导的心输出量增加可致前循环CBF减少，而对后循环未见影响，负荷状态下舒张压增加与CBF减少相关。.