NONINVASIVE EVALUATION OF CORONARY BYPASS GRAFT PATENCY

主动脉冠状动脉旁路移植术是一种常用的 冠心病的介入治疗 疾病 然而，众所周知，这样的开放性是不可能的。 移植物可随时间逐渐减少。 The definitive 移植物通畅性的确认是选择性血管造影术。 这 手术是昂贵的，侵入性的，并带有一定程度的 发病率和死亡率。 替代非侵入性方法， 评估移植物通畅性包括铊扫描，多普勒， 超声心动图、IV数字减影血管造影和计算机 断层扫描（CT）。 在这些替代品中，只有CT实现了 足够的准确性，以保证继续考虑作为一个 血管造影的无创替代方法。 然而，CT 方法有些昂贵，提供可观的辐射 剂量的心脏，并需要一个显着的学习曲线，如果假 应避免负面和假阳性评价。 该提案的目的是开发一种新的非侵入性 移植物通畅性评价的技术，但一个是 便宜，需要CT扫描辐射剂量的1/10， 避免了CT技术中固有的移植物识别问题 通过使用一种将身份识别与移植分离的程序， 评价 这项新技术将使用一个小型专用的两个- 适合于连接到导管的检测器X射线扫描系统 实验室荧光透视装置或小型便携式X射线发生器。 这 扫描系统将使用X射线散射和X射线感应 荧光用于旁路移植物的定位和评价 分别 本提案的目的是设计、建造、 测试和验证这个新系统 测试和验证将 在机械模型、动物模型（犬）和 人类

Aortocoronary bypass graft surgery is a frequently employed therapeutic intervention in the management of coronary heart disease. It is well known, however, that the patency of such grafts can decrease progressively over time. The definitive confirmation of a graft's patency is selective angiography. This procedure is costly, invasive, and carries some degree of morbidity and mortality. Alternative noninvasive methods for evaluating graft patency have included thallium scans, doppler- echo, IV digital subtraction angiography, and computed tomography (CT). Of these alternatives only CT has achieved sufficient accuracy to warrant continued consideration as a noninvasive alternative to angiography. Nevertheless, CT methods are somewhat expensive, deliver an appreciable radiation dose to the heart, and require a significant learning curve if false negative and false positive evaluations are to be avoided. It is the aim of this proposal to develop a new noninvasive technique for the evaluation of graft patency, but one that is inexpensive, requires 1/10 of the radiation dose of a CT scan, and avoids problems of graft identification inherent in CT techniques by using a procedure that separates identification from graft evaluation. This new technique will use a small dedicated two- detector x-ray scanning system suitable for attachment to a cath lab fluoroscopic unit or a small portable x-ray generator. This scanning system will use x-ray scatter and x-ray induced fluorescence for the location and evaluation of by-pass grafts respectively. The aim of this proposal is to design, construct, test, and validate this new system. Testing and validation will be performed on mechanical models, animal models (canine), and humans.