Bogren H G, Mohiaddin R H, Yang G Z, Kilner P J, Firmin D N
Royal Brompton Hospital, National Heart and Lung Institute, London, United Kingdom.
J Thorac Cardiovasc Surg. 1995 Sep;110(3):704-14. doi: 10.1016/S0022-5223(95)70102-8.
Magnetic resonance imaging with multidirectional cine velocity mapping was used to study relationships between aortic blood flow patterns and the geometry of thoracic aortic aneurysms and grafts. Ten patients with 13 thoracic aortic aneurysms, single or multiple, or grafts (4) participated in the study. The causes of disease were atherosclerosis (4), Marfan's syndrome (2), trauma (1), and unknown (1), and there were two dissections. Spin-echo imaging and cine velocity mapping in 10 mm thick slices with vertical and horizontal velocity encoding were done. Maps of the two velocity components were processed into multiple computer-generated streaks whose orientation and length corresponded to velocity vectors in the chosen plane. The dynamic arrow maps were compared with previously reported aortic arrow maps from normal subjects. The forward flow occupied the entire lumen in the normal aorta in systole and small vortices were only present in the sinuses of Valsalva. Atherosclerotic aneurysms in the ascending aorta were located at the anterior right and had oblique, eccentric jet flows that created a large secondary vortex in the aneurysm. Patients with Marfan's syndrome had a central jet and two large vortices, one on each side. All other aneurysms, dissections, and grafts had irregular flows and vortices not seen in normal subjects. Magnetic resonance imaging with multidirectional velocity mapping is a powerful noninvasive tool to assess morphologic features and disturbed blood flow in aortic aneurysms and grafts. Recognizably altered flow patterns were found to be associated with altered vessel geometry. The significance of this requires further investigation.
采用多方向电影速度成像磁共振成像技术，研究胸主动脉瘤和移植物的主动脉血流模式与几何形态之间的关系。10例患有13个单发或多发胸主动脉瘤或移植物（4个）的患者参与了本研究。病因包括动脉粥样硬化（4例）、马凡综合征（2例）、创伤（1例）和病因不明（1例），其中有2例夹层。采用自旋回波成像和10mm厚切片的电影速度成像，进行垂直和水平速度编码。将两个速度分量的图像处理成多个计算机生成的条纹，其方向和长度与所选平面内的速度矢量相对应。将动态箭头图像与先前报道的正常受试者的主动脉箭头图像进行比较。正常主动脉在收缩期正向血流占据整个管腔，仅在主动脉窦处存在小涡流。升主动脉粥样硬化性动脉瘤位于右前方，有倾斜、偏心的射流，在动脉瘤内形成一个大的继发涡流。马凡综合征患者有一个中央射流和两个大涡流，两侧各一个。所有其他动脉瘤、夹层和移植物都有正常受试者未见的不规则血流和涡流。多方向速度成像磁共振成像是评估主动脉瘤和移植物形态特征和血流紊乱的有力无创工具。发现明显改变的血流模式与血管几何形态改变有关。其意义有待进一步研究。
