UNASSIGNED:经导管主动脉瓣植入(TAVI)已成为老年患者主动脉瓣手术替代的替代方法。然而,TAVI患者可能患有瓣周漏(PVL)。检测和分级通常通过超声心动图进行,但受决议的限制,2D可视化和操作员依赖关系。4D流磁共振成像(MRI)是一种有前途的替代方案,在TAVI患者中没有达到临床应用。这项研究的目的是应用3D打印技术来评估TAVI后PVL的血流模式和血流动力学,利用4D流MRI和标准超声。
未经评估:MR兼容,解剖学上左心室,主动脉根部,升主动脉模型是通过结合3D打印部件和各种软硅胶材料来制造的,以匹配生理特征。AbbottPortico™阀门用于连续顺行流(12-22l/min),不同跨瓣压(60-110mmHg)的逆行血流,和生理脉动血流动力学(主动脉压:120/80mmHg,心输出量:5l/min)在TAVI支架上方和下方进行时间分辨MR测量,并在完全相同的设置下与彩色多普勒超声测量进行比较。
UNASSIGNED:来自MRI的连续顺行流量测量与流量计测量在很大程度上一致,最大误差仅为7%。在逆行配置中,从MR测量中可以看到瓣膜旁漏,但流量被高估了33%。脉动设置中的4DMRI测量显示单个主PVL,彩色多普勒测量也证实了这一点,和速度相似(2.0m/s与1.7米/秒)。
未经评估:4DMRI技术用于定性评估患者的血流,MR兼容和灵活的模型,只有通过使用3D打印技术才成为可能。升主动脉的血流模式,PVL的识别和量化是可能的,PVL的位置和范围通过超声测量得到确认.4DMRI血流技术可以评估TAVI支架下方升主动脉和左心室的血流模式,在识别PVL方面效果良好。然而,通过提供三维可视化瓣膜旁射流的能力,证明其在超声上的能力,额外的时间和金钱支出。
UNASSIGNED: Transcatheter aortic valve implantation (TAVI) has become an alternative to surgical replacement of the aortic valve elderly patients. However, TAVI patients may suffer from paravalvular leaks (PVL). Detecting and grading is usually done by echocardiography, but is limited by resolution, 2D visualization and operator dependency. 4D flow magnetic resonance imaging (MRI) is a promising alternative, which did not reach clinical application in TAVI patients. The aim of this study was applying 3D printing technologies in order to evaluate flow patterns and hemodynamics of PVLs following TAVI, exploiting 4D flow MRI and standard ultrasound.
UNASSIGNED: An MR-compatible, anatomically left ventricle, aortic root, and ascending aorta model was fabricated by combining 3D-printed parts and various soft silicone materials to match physiological characteristics. An Abbott Portico™ valve was used in continuous antegrade flow (12-22 l/min), retrograde flow with varying transvalvular pressures (60-110 mmHg), and physiological pulsatile hemodynamics (aortic pressure: 120/80 mmHg, cardiac output: 5 l/min) Time-resolved MR measurements were performed above and below the TAVI stent and compared with color Doppler ultrasound measurements in exactly the same setup.
UNASSIGNED: The continuous antegrade flow measurements from MRI largely agreed with the flowmeter measurements, and a maximum error of only 7% was observed. In the retrograde configuration, visualization of the paravalvular leaks was possible from the MR measurements, but flow was overestimated by up to 33%. The 4D MRI measurement in the pulsatile setup revealed a single main PVL, which was also confirmed by the color Doppler measurements, and velocities were similar (2.0 m/s vs. 1.7 m/s).
UNASSIGNED: 4D MRI techniques were used to qualitatively assess flow in a patient-specific, MR-compatible and flexible model, which only became possible through the use of 3D printing techniques. Flow patterns in the ascending aorta, identification and quantification of PVLs was possible and the location and extent of PVLs were confirmed by ultrasound measurements. The 4D MRI flow technique allowed evaluation of flow patterns in the ascending aorta and the left ventricle below the TAVI stent with good results in identifying PVLs, demonstrating its capabilities over ultrasound by providing the ability to visualize the paravalvular jets in three dimensions at however, additional expenditure of time and money.