PULSATILE VELOCITY-MEASUREMENTS IN A MODEL OF THE HUMAN ABDOMINAL-AORTA UNDER RESTING CONDITIONS
PULSATILE VELOCITY-MEASUREMENTS IN A MODEL OF THE HUMAN ABDOMINAL-AORTA UNDER RESTING CONDITIONS
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DOI：
10.1115/1.2895740
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发表时间：
1994-08-01
影响因子：
1.7
通讯作者：
KU, DN
中科院分区：
文献类型：
--
作者：
MOORE, JE;KU, DN
在近壁速度方向的振荡已被发现与动脉粥样硬化斑块定位在颈动脉窦分叉。然而，这些情况是否可以解释动脉粥样硬化形成的其他部位的疾病的定位仍然没有得到证实。腹主动脉是一段相对较直的动脉，是临床疾病的重要部位。本研究旨在量化腹主动脉中的速度场，以确定血流动力学速度方向的局部差异是否可以解释该段疾病的定位。磁共振成像测速仪被用来测量在解剖学上准确的体外模型的腹主动脉的脉动速度分布。肾上腺主动脉中测得的速度是层流和反向最低限度，比较以及Womersley流的理论解（r=0.96）。在离壁1 mm处，近壁处的时间平均流速为+3.0cm/s。在肾下主动脉，最大流速偏向前壁。在后壁，速度方向振荡，82%的心动周期是逆行的。后壁附近的时间平均流速为-12.5 cm/s，而前壁附近为+3.00 cm/s。在主动脉分叉处，最大和最小速度的位置集中在外侧后壁附近。这项研究量化了腹主动脉中可能存在的低和振荡速度的大小，并表明在静息条件下逆行方向的速度与动脉粥样硬化斑块的分布之间存在很强的关系。
Oscillations in near-wall velocity direction have been found to correlate with atherosclerotic plaque localization in the carotid sinus bifurcation. However, it remains unproven whether these conditions could account for the localization of the disease at other sites where atherosclerosis forms. The abdominal aorta is an important site of clinical disease in a relatively straight segment of artery. This study was initiated to quantify the velocity field in the abdominal aorta in order to determine if local differences in hemodynamic velocity directions could account for the localization of disease in this segment. Magnetic Resonance Imaging velocimetry was used to measure the pulsatile velocity profiles in an anatomically accurate in vitro model of the abdominal aorta. Velocities measured in the suprarenal aorta were laminar and reversed minimally, comparing well with theoretical solutions of Womersley flow (r=0.96). The time-averaged velocity was +3.0 cm/s near-wall at a distance of 1 mm away from the wall. In the infrarenal aorta, the maximal velocities were skewed toward the anterior wall. At the posterior wall, velocity oscillated in direction and was retrograde for 82 percent of the cardiac cycle. The time-averaged velocity near the posterior wall was - 12.5 cm/s as compared to +3.00 cm/s near the anterior wall. At the aortic bifurcation, the locations of maximal and minimal velocities in this slice were concentrated near the lateral posterior walls. This study quantifies the magnitude of low and oscillatory velocity that may exist in the abdominal aorta and suggests that there is a strong relationship between the velocities in the retrograde direction under resting conditions and the distribution of atherosclerotic plaque.