Powell A J, Maier S E, Chung T, Geva T
Department of Cardiology, Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
Pediatr Cardiol. 2000 Mar-Apr;21(2):104-10. doi: 10.1007/s002469910014.
Quantification of blood flow in vessels provides valuable information that aids management decisions in a variety of cardiac conditions. Current flow measurement techniques are often limited by accuracy, time resolution, convenience, or anatomic localization. This study examined the accuracy of a commercially available phase-velocity cine magnetic resonance imaging (PVC MRI) technique to quantify flow rate in a pulsatile flow phantom. In addition, the equivalence of PVC MRI measurements of pulmonary and systemic flow was evaluated in children and adults without any pathologic shunt. Using a pulsatile flow phantom, volume flow rates measured by PVC MRI were compared to those by a transit-time ultrasound flowmeter over a range of flow rates (1.25-3.5 L/min, 13 trials). Close agreement was found between these techniques (y = 1.02x - 0.02, r = 0.99, Bland-Altman bias = -0.045 L/min, 95% limits of agreement = -0. 19-0.10 L/min). Twenty subjects (median age 12.8 years, range 0.7-49 years) with no pathologic shunt underwent PVC MRI measurement of blood flow in the main pulmonary artery (Q(p)) and the ascending aorta (Q(s)). Data processing time for each location was 20 minutes. The Q(p)/Q(s) ratio closely approximated unity (mean = 0.99, SD = 0. 10, range 0.85-1.19). Interobserver agreement was excellent (Bland-Altman bias = 0.09 L/min, 95% limits of agreement = 0.15-0.33 L/min). PVC MRI is an accurate technique to quantify pulsatile blood flow at a specific location. It can be used to noninvasively calculate Q(p) and Q(s) under normal flow conditions.
血管内血流的定量分析可提供有价值的信息，有助于对各种心脏疾病做出管理决策。目前的血流测量技术常常受到准确性、时间分辨率、便利性或解剖定位的限制。本研究检验了一种商用相速度电影磁共振成像（PVC MRI）技术在搏动血流模型中定量流速的准确性。此外，还评估了在无任何病理性分流的儿童和成人中，PVC MRI测量肺循环和体循环血流的等效性。使用搏动血流模型，在一系列流速（1.25 - 3.5 L/分钟，共13次试验）下，将PVC MRI测量的体积流速与通过渡越时间超声流量计测量的流速进行比较。发现这些技术之间具有高度一致性（y = 1.02x - 0.02，r = 0.99，Bland - Altman偏差 = -0.045 L/分钟，95%一致性界限 = -0.19 - 0.10 L/分钟）。20名无病理性分流的受试者（年龄中位数12.8岁，范围0.7 - 49岁）接受了PVC MRI对主肺动脉（Q(p)）和升主动脉（Q(s)）血流的测量。每个部位的数据处理时间为20分钟。Q(p)/Q(s)比值非常接近1（平均值 = 0.99，标准差 = 0.10，范围0.85 - 1.19）。观察者间一致性良好（Bland - Altman偏差 = 0.09 L/分钟，95%一致性界限 = 0.15 - 0.33 L/分钟）。PVC MRI是一种准确的技术，可用于定量特定部位的搏动血流。它可用于在正常血流条件下无创计算Q(p)和Q(s)。
