Supraceliac and Infrarenal Aortic Flow in Patients with Abdominal Aortic Aneurysms: Mean Flows, Waveforms, and Allometric Scaling Relationships.
Supraceliac and Infrarenal Aortic Flow in Patients with Abdominal Aortic Aneurysms: Mean Flows, Waveforms, and Allometric Scaling Relationships.
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DOI：
10.1007/s13239-010-0004-8
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发表时间：
2010-03
影响因子：
1.8
通讯作者：
Taylor, Charles A
中科院分区：
文献类型：
--
作者：
Les, Andrea S;Yeung, Janice J;Schultz, Geoffrey M;Herfkens, Robert J;Dalman, Ronald L;Taylor, Charles A
血流动力学被认为在腹主动脉瘤（AAA）生长中起关键作用。计算机模拟和体外模拟可用于研究这些力，但需要精确的主动脉几何形状和边界条件。许多AAA模拟使用患者特定的几何形状，但使用来自单个无关健康年轻成人的入口边界条件。在这项研究中，我们使用1.5T MR扫描仪对43例AAA患者进行了成像。使用24帧心脏门控单分量相位对比磁共振成像序列测量腹腔上（SC）和肾下（IR）主动脉的体积流量，其中通常需要模拟流量信息。对于前36名患者，将单个波形内插到12模式傅立叶曲线，峰值对齐并取平均值。从平均SC和IR流量与体重、身高、体表面积（BSA）和无脂肪体重的双对数图中推导出异速生长比例方程。最后7例患者的数据用于验证我们的模型。SC和IR平均波形均具有老年人特有的双相形状，心动周期内的平均SC和IR流量分别为51.2 ± 10.3和17.5 ± 5.44 mL/s。对数-对数图的线性回归显示，BSA对平均SC（R2 = 0.29）和IR血流（R2 = 0.19）的预测性最强，组合R2最高。当取平均值时，最后7名患者的测量波形和预测波形一致。我们提出了一种方法来估计SC和IR平均流量和波形AAA模拟。
Hemodynamic forces are thought to play a critical role in abdominal aortic aneurysm (AAA) growth. In silico and in vitro simulations can be used to study these forces, but require accurate aortic geometries and boundary conditions. Many AAA simulations use patient-specific geometries, but utilize inlet boundary conditions taken from a single, unrelated, healthy young adult. In this study, we imaged 43 AAA patients using a 1.5 T MR scanner. A 24-frame cardiac-gated one-component phase-contrast magnetic resonance imaging sequence was used to measure volumetric flow at the supraceliac (SC) and infrarenal (IR) aorta, where flow information is typically needed for simulation. For the first 36 patients, individual waveforms were interpolated to a 12-mode Fourier curve, peak-aligned, and averaged. Allometric scaling equations were derived from log–log plots of mean SC and IR flow vs. body mass, height, body surface area (BSA), and fat-free body mass. The data from the last seven patients were used to validate our model. Both the SC and IR averaged waveforms had the biphasic shapes characteristic of older adults, and mean SC and IR flows over the cardiac cycle were 51.2 ± 10.3 and 17.5 ± 5.44 mL/s, respectively. Linear regression of the log–log plots revealed that BSA was most strongly predictive of mean SC (R2 = 0.29) and IR flow (R2 = 0.19), with the highest combined R2. When averaged, the measured and predicted waveforms for the last seven patients agreed well. We present a method to estimate SC and IR mean flows and waveforms for AAA simulation.