Department of Neurology, Universitätsmedizin Mannheim, University of Heidelberg, Mannheim, Germany.
J Cereb Blood Flow Metab. 2011 Aug;31(8):1716-24. doi: 10.1038/jcbfm.2011.14. Epub 2011 Mar 2.
Real-time ultrasound perfusion imaging (rt-UPI) allows visualization of microbubbles flowing through the cerebral microvasculature. We hypothesized that analysis of microbubble tissue replenishment would enable for characterization of perfusion deficits in acute middle cerebral artery (MCA) territory stroke. Twenty-three patients (mean age 70.2 ± 13.2 years, 9 weeks) were included. Sequential images of bubble replenishment were acquired by transcranial rt-UPI at low mechanical index immediately after microbubble destruction. Different parameters were calculated from regions of interest (ROIs): real-time time to peak (rt-TTP), rise rate (β), and plateau (A) of acoustic intensity, and A × β was used as an index of blood flow. Results were compared with diffusion-weighted and perfusion magnetic resonance imaging. Parameters of rt-UPI had lower values in ROIs of ischemic as compared with normal tissue (β=0.58 ± 0.40 versus 1.25 ± 0.83; P=0.001; A=1.44 ± 1.75 versus 2.63 ± 2.31; P=0.05; A × β=1.14 ± 2.25 versus 2.98 ± 2.70; P=0.01). Real-time time to peak was delayed in ischemic tissue (11.43 ± 2.67 versus 8.88 ± 1.66 seconds; P<0.001). From the analysis of receiver operating characteristic curves, β and A × β had the largest areas under the curve with optimal cutoff values of β<0.76 and A × β<1.91. We conclude that rt-UPI with analysis of microbubble replenishment correctly identifies ischemic brain tissue in acute MCA stroke.
实时超声灌注成像（rt-UPI）可用于可视化通过脑微循环流动的微泡。我们假设分析微泡组织再填充将能够对急性大脑中动脉（MCA）区域卒中的灌注不足进行特征描述。共纳入 23 例患者（平均年龄 70.2±13.2 岁，9 周）。通过经颅 rt-UPI 在微泡破坏后立即以低机械指数获得微泡再填充的连续图像。通过感兴趣区（ROI）计算不同参数：实时峰值时间（rt-TTP）、上升率（β）和强度的平台（A），并将 A×β用作血流指数。结果与弥散加权和灌注磁共振成像进行比较。与正常组织相比，ROI 中的 rt-UPI 参数值较低（β=0.58±0.40 对 1.25±0.83；P=0.001；A=1.44±1.75 对 2.63±2.31；P=0.05；A×β=1.14±2.25 对 2.98±2.70；P=0.01）。缺血组织的实时峰值时间延迟（11.43±2.67 对 8.88±1.66 秒；P<0.001）。通过接收者操作特征曲线分析，β 和 A×β 的曲线下面积最大，最佳截断值为β<0.76 和 A×β<1.91。我们得出结论，rt-UPI 分析微泡再填充可正确识别急性 MCA 卒中的缺血性脑组织。
