Viereck Jason, Ruberg Frederick L, Qiao Ye, Perez Alexandra S, Detwiller Kara, Johnstone Michael, Hamilton James A
Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118, USA.
Arterioscler Thromb Vasc Biol. 2005 Jan;25(1):240-5. doi: 10.1161/01.ATV.0000149673.00564.0a. Epub 2004 Nov 4.
MRI would be a valuable noninvasive diagnostic tool to study plaque-associated thrombi. We defined the imaging characteristics of these thrombi, composed primarily of platelets and fibrin, and distinguished them clearly from the vessel lumen and underlying atherosclerotic plaque in an animal model of plaque rupture.
After triggering plaque rupture in New Zealand White male rabbits, segments of infrarenal aorta containing either red or white thrombi were fixed in formalin. Compared with postmortem red cell-rich thrombi, atherothrombi yielded complex magnetic resonance images with intermediate signal intensity in standard T1- and T2-weighted imaging sequences and were often difficult to distinguish from the aortic wall. Diffusion-weighted imaging sequences revealed restricted diffusion of the atherothrombus relative to the vessel wall and provided excellent contrast. The apparent diffusion coefficient of the thrombus is 1.0x10(-3) mm2/s, compared with 1.5x10(-3) mm2/s in tissue. Similar results were obtained using purified aggregated platelets.
We present the first detailed description of the MRI appearance of plaque rupture-associated thrombosis in histologically validated platelet-rich thrombi. Diffusion-weighted imaging provided the best distinction between thrombus and vessel wall and has potential application for the noninvasive in vivo detection of atherothrombosis.
磁共振成像（MRI）将成为研究斑块相关血栓的一种有价值的非侵入性诊断工具。我们定义了这些主要由血小板和纤维蛋白组成的血栓的成像特征，并在斑块破裂的动物模型中，将它们与血管腔和潜在的动脉粥样硬化斑块清楚地区分开来。
在触发新西兰雄性白兔的斑块破裂后，将含有红色或白色血栓的肾下腹主动脉段固定于福尔马林中。与死后富含红细胞的血栓相比，动脉粥样硬化血栓在标准T1加权和T2加权成像序列中产生具有中等信号强度的复杂磁共振图像，并且常常难以与主动脉壁区分开。扩散加权成像序列显示动脉粥样硬化血栓相对于血管壁的扩散受限，并提供了出色的对比度。血栓的表观扩散系数为1.0×10（-3）mm2/s，而组织中的表观扩散系数为1.5×10（-3）mm2/s。使用纯化的聚集血小板也获得了类似的结果。
我们首次详细描述了经组织学验证的富含血小板血栓中与斑块破裂相关血栓形成的MRI表现。扩散加权成像在血栓与血管壁之间提供了最佳区分，并且在动脉粥样硬化血栓形成的非侵入性体内检测中具有潜在应用价值。
