■已经证明主动脉扩张速率受主动脉血流动力学改变的影响,如归一化流量位移(FDN)和壁面剪应力(WSS)。然而,衰老对主动脉血流动力学的影响尚未被描述.
■4D-FlowMRI衍生的主动脉血流动力学在升主动脉瘤患者(平均值±标准偏差:46±1mm)和健康志愿者(主动脉直径30±1mm)的升主动脉中进行了10年和8年的长期随访,分别。在所有时间点,与健康的志愿者相比,患者表现出更高的FDN幅度(7%±1%vs.3%±1%)和WSS角度(36°±3°与24°±6°),和较低的WSS幅度(565±100mPavs.910±115mPa),轴向WSS(426±71mPavs.800±108mPa)和周向WSS(297±64mPavs.340±85mPa)。患者和健康志愿者表现出不同的主动脉扩张率(回归斜率±标准误差:0.2±0.1vs.每年0.1±0.2毫米)和FDN趋势(0.1%±0.1%与每年0.1%±0.2%),WSS大小(22±9vs.每年35±13mPa),轴向WSS(19±4vs.每年37±7mPa),周向WSS(9±8vs.每年5±15mPa),和WSS角度(-0.5°±0.4°与每年-0.8°±1.0°)。
■主动脉血流动力学参数在本组病例中受老化和主动脉直径的轻微影响。由于主动脉血流动力学参数与先前研究的主动脉扩张相关,这两个受试者的结果表明,当个体处于衰老和扩张状态时,主动脉扩张率将保持不变。
UNASSIGNED: It has been demonstrated that the rate of aortic dilatation is influenced by alteration of aortic hemodynamics, such as normalized flow displacement (FDN) and wall shear stress (WSS). However, the effects of ageing on aortic hemodynamics have not yet been described.
UNASSIGNED: 4D-Flow MRI derived aorta hemodynamics were derived in the ascending aorta of a patient with ascending aortic aneurysm (mean ± standard deviation: 46 ± 1 mm) and a healthy volunteer (aortic diameter 30 ± 1 mm) with long-term follow-up of ten and eight years, respectively. At all timepoints, compared to the healthy volunteer, the patient demonstrated higher magnitudes of FDN (7% ± 1% vs. 3% ± 1%) and WSS angle (36° ± 3° vs. 24° ± 6°), and lower WSS magnitude (565 ± 100 mPa vs. 910 ± 115 mPa), axial WSS (426 ± 71 mPa vs. 800 ± 108 mPa) and circumferential WSS (297 ± 64 mPa vs. 340 ± 85 mPa). The patient and healthy volunteer demonstrated different aortic dilatation rates (regression slope ± standard error: 0.2 ± 0.1 vs. 0.1 ± 0.2 mm per year) and trends in FDN (0.1% ± 0.1% vs. 0.1% ± 0.2% per year), WSS magnitude (22 ± 9 vs. 35 ± 13 mPa per year), axial WSS (19 ± 4 vs. 37 ± 7 mPa per year), circumferential WSS (9 ± 8 vs. 5 ± 15 mPa per year), and WSS angle (-0.5° ± 0.4° vs. -0.8° ± 1.0° per year).
UNASSIGNED: Aortic hemodynamic parameters are marginally affected by ageing and the aortic diameter in this case series. Since aortic hemodynamic parameters have been associated with aortic dilation by previous studies, the outcomes of the two subjects suggest that the aortic dilatation rate will remain constant while individuals are ageing and dilating.