Hänni Mari, Leppänen Olli, Smedby Orjan
Department of Radiology, Oncology, and Radiation Science, Section of Radiology, Uppsala University, 751 85 Uppsala, Sweden.
Int J Biomed Imaging. 2012;2012:747264. doi: 10.1155/2012/747264. Epub 2012 Dec 19.
Rationale and Objectives. Testing a quantitative, noninvasive method to assess postangioplasty vessel wall changes in an animal model. Material and Methods. Six New Zealand white rabbits were subjected to atherosclerotic injury, including cholesterol-enriched diet, deendothelialization, and percutaneous transluminal angioplasty (PTA) in the distal part of abdominal aorta (four weeks after deendothelialization). The animals were examined with a 1.5T MRI scanner at three times as follows: baseline (six weeks after diet start and two days after PTA) and four weeks and 10 weeks after-PTA. Inflow angiosequence (M2DI) and proton-density-weighted sequence (PDW) were performed to examine the aorta with axial slices. To identify the inner and outer vessel wall boundaries, a dynamic contour algorithm (Gradient Vector Flow Snakes) was applied to the images, followed by calculation of the vessel wall dimensions. The results were compared with histopathological analysis. Results. The wall thickness in the lesion was significantly higher than in the control region at 4 and 10 weeks, reflecting induction of experimentally created after-angioplasty lesion. At baseline, no significant difference between the two regions was present. Conclusions. It is possible to follow the development of vessel wall changes after-PTA with MRI in this rabbit model.
原理与目的。在动物模型中测试一种定量、非侵入性方法，以评估血管成形术后血管壁的变化。材料与方法。对6只新西兰白兔进行动脉粥样硬化损伤，包括给予富含胆固醇的饮食、去除内皮以及在腹主动脉远端进行经皮腔内血管成形术（PTA，在内皮去除后4周）。使用1.5T磁共振成像扫描仪对动物进行三次检查，如下：基线期（开始饮食6周后及PTA后2天）以及PTA后4周和10周。采用流入血管序列（M2DI）和质子密度加权序列（PDW），通过轴向切片检查主动脉。为确定血管壁的内、外边界，对图像应用动态轮廓算法（梯度向量流蛇形算法），随后计算血管壁尺寸。将结果与组织病理学分析进行比较。结果。在4周和10周时，病变部位的壁厚显著高于对照区域，这反映了血管成形术后实验性损伤的诱导。在基线期，两个区域之间无显著差异。结论。在该兔模型中，利用磁共振成像有可能跟踪血管成形术后血管壁变化的发展情况。
