3．0T高场磁共振血管内成像无环线圈成像小型猪动脉粥样斑块的可行性

Feasibility of using intravascular ioopless monopole antenna to image atherosclerotic plaque in a porcine model with 3. 0 T magnetic resonance imaging

目的探讨在3．0T高场磁共振（MR）下，利崩自制的血管内磁共振成像无环线圈（intravascular loopless monopole antenna，ILMA）高分辨成像小型猪腹主动脉及双侧髂动脉粥样硬化斑块的可行性。方法小型猪6只，采朋动脉内膜拉伤并辅以高脂饲料的方法建立动脉粥样硬化（AS）模型。采用自制的ILMA行腹主动脉及双侧髂总动脉MR检查，检查序列包括T1加权像（DIR—T1WI）、T2加权像（FSE—T2WI）等多序列扫描。对获得的同层面图像进行分析，手动描绘血管的内外膜，计算血管内径及外径的横截面积、管壁横截面大小。最后，处死动物行组织病理学检查，以该结果为参考标准，分析ILMA检测斑块性质及成分的准确性。结果6只小型猪的AS模型均成功建立。ILMA技术在测量血管横截面积、管腔横截面积和管壁横截面积方面均与病理学检测结果有很好的一致性（r=0．98、0．95和0．96，P〈0．001）。在检测AS斑块成分方面，ILMA检测脂质成分的敏感度为77％、特异度为69％，纤维成分的敏感度为78％、特异度为73％，c值分别为0．75±0．19和0．78±0．18（P〈0．01）。ILMA检测钙化成分的敏感度和特异度均为100％。ILMA测量的腹主动脉血管平均横截面积为124．08mm2，管腔平均横截面积为49．72mm2，管壁平均面积为74．37mm2，病理结果比较，ILMA轻度高估以上指标。结论应用改良的ILMA可成功对As斑块进行成像，在描绘As斑块大小、管壁横截面积等指标及检测斑块性质和成分等方面与病理检测有较好的一致性。

Objective To investigate the feasibility of using intravascular loopless monopole antenna （ILMA） to image atherosclerosis plaque in a porcine model with 3.0T magnetic resonance imaging （MRI）. Methods Atherosclerosis model was established by feeding high fat diet combined with balloon catheter injury to the endothelium in 6 pigs. After 3 months, animals underwent MRI and ILMA examination. The ILMA was invasively inserted to the distal part of abdominal vein and bilateral common iliac veins. MR sequences including T1 weighted imaging （T1WI）, T2WI were obtained. MR image data were transferred to post-processing station. Luminal border and external elastic membrane of the vessel were reconstructed based on the MR images. After co-register these images, vessel area, lumen area, vessel wall area and plaque burden in the same lesions imaged by different modality were calculated and compared. Finally, all animals were scarified and hematoxylin eosin （HE） staining was performed in the targeted vessels. Diagnostic accuracy of MR in delineating vessel wall and detecting plaque were analyzed and calculated by comparing with pathological results. Results The atheroselerotic model was successfully established in all 6 pigs. Good agreement of delineating vessel area, lumen area vessel, wall area and plaque burden were found between MRI and pathology with r value of 0. 98, 0. 95, and 0. 96, respectively （ P 〈 0. 001 ）. Compared with pathological findings, the plaque component in corresponding area imaged by MR was as follows： sensitivity and specificity of detecting lipid plaque （P 〈0. O1 ）. The sensitivily and speeif＇ieily of deleeling calcified plaque uere 100%. ILMA results showed that the awtrage lumen area was 49. 72 mm2 , arage vessel area was 124. 08 mm2, and the average vessel wall area was 74. 37 mm2, ILMA slightly OW^l＇eslimaled Ihese indexes as compared wilh pathological results. Conclusion The results showed thai II,MA could be used Io image deepened artery and atheroselerolie plaque. Detected plaque size, vessel area, lumen area vessel, wall area, and plaque burden were eompavalble to pathoh）gieal findings. It may thus provide an alternative melhod for detecting atherosclerotie plaque in future research work.