Physics For Medicine Paris, INSERM U1273, ESPCI Paris, PSL Research University, CNRS UMR 7587, France. Author to whom any correspondence should be addressed.
Phys Med Biol. 2019 Apr 10;64(8):085013. doi: 10.1088/1361-6560/ab1107.
The goal of this study was to demonstrate the feasibility of semi-automatic evaluation of cardiac Doppler indices in a single heartbeat in human hearts by performing 4D ultrafast echocardiography with a dedicated sequence of 4D simultaneous tissue and blood flow Doppler imaging. 4D echocardiography has the potential to improve the quantification of major cardiac indices by providing more reproducible and less user dependent measurements such as the quantification of left ventricle (LV) volume. The evaluation of Doppler indices, however, did not benefit yet from 4D echocardiography because of limited volume rates achieved in conventional volumetric color Doppler imaging but also because spectral Doppler estimation is still restricted to a single location. High volume rate (5200 volume s) transthoracic simultaneous tissue and blood flow Doppler acquisitions of three human LV were performed using a 4D ultrafast echocardiography scanner prototype during a single heartbeat. 4D color flow, 4D tissue Doppler cineloops and spectral Doppler at each voxel were computed. LV outflow tract, mitral inflow and basal inferoseptal locations were automatically detected. Doppler indices were derived at these locations and were compared against clinical 2D echocardiography. Blood flow Doppler indices E (early filling), A (atrial filling), E/A ratio, S (systolic ejection) and cardiac output were assessed on the three volunteers. Simultaneous tissue Doppler indices e' (mitral annular velocity peak), a' (late velocity peak), e'/a' ratio, s' (systolic annular velocity peak), E/e' ratio were also estimated. Standard deviations on three independent acquisitions were averaged over the indices and was found to be inferior to 4% and 8.5% for Doppler flow and tissue Doppler indices, respectively. Comparison against clinical 2D echocardiography gave a p value larger than 0.05 in average indicating no significant differences. 4D ultrafast echocardiography can quantify the major cardiac Doppler indices in a single heart beat acquisition.
本研究旨在通过使用专用的 4D 同时组织和血流多普勒成像序列进行 4D 超快速超声心动图，证明在单次心跳中半自动评估人心脏多普勒指数的可行性。4D 超声心动图有可能通过提供更具可重复性和更少用户依赖性的测量（例如左心室 (LV) 容积的量化）来改善主要心脏指数的定量。然而，由于在常规容积彩色多普勒成像中实现的有限体积率，以及由于频谱多普勒估计仍然限于单个位置，因此多普勒指数的评估尚未受益于 4D 超声心动图。使用 4D 超快速超声心动图扫描仪原型在单次心跳期间对三个人类 LV 进行了 5200 体积/秒的高体积率经胸同时组织和血流多普勒采集。计算了每个体素的 4D 彩色流量、4D 组织多普勒电影循环和频谱多普勒。自动检测 LV 流出道、二尖瓣流入和基底下间隔位置。在这些位置导出多普勒指数，并与临床 2D 超声心动图进行比较。对三名志愿者评估了血流多普勒指数 E（早期充盈）、A（心房充盈）、E/A 比、S（收缩射血）和心输出量。还估计了同时组织多普勒指数 e'（二尖瓣环速度峰值）、a'（晚期速度峰值）、e'/a'比、s'（收缩环速度峰值）、E/e'比。将三个独立采集的指数上的标准偏差平均化，发现血流和组织多普勒指数的标准偏差分别小于 4%和 8.5%。与临床 2D 超声心动图的比较平均表明 p 值大于 0.05，表明没有显著差异。4D 超快速超声心动图可以在单次心跳采集时量化主要心脏多普勒指数。
