MRI-safe 3Dl intracardiac ultrasound catheter for cardiovascular intervention

描述（由申请人提供）：症状性成人和儿童结构性心脏病影响超过2.9%的美国人口，不包括心肌病和心律失常。虽然非手术方法是缓解症状的首选途径，但即使是常见的手术，如房间隔缺损封堵术，也可能是困难的、旷日持久的或不成功的，这不仅是因为可用导管器械的局限性，也是因为图像引导不足。当前的2D和有限体积的3D心内超声导管不提供合适的全体积正面图像来真实的描绘复杂的心脏结构，不描绘导管的实时导航，并且需要连续的X射线引导。超声探头的小型化，以提供心脏病理和导管器械的不间断实时全容积术中三维正面描绘，将代表图像引导介入的巨大进步。此外，从一开始就设计3D ICE探头以在MRI期间以及在常规X射线期间安全地操作，这将通过实现完全无辐射的非手术导管导航来显著地推进或甚至革命性地改变经导管治疗的能力。我们的提案旨在实现这样一种导管，即3D MRICE，基于NHLBI和格鲁吉亚理工学院两个小组的密切合作，以及NIH临床中心用于导管制造、临床前评价和临床试验的独特资源。我们使用CMUT-on-CMOS技术和大规模并行RF数据多路复用来实现超微型、单芯片体积超声成像系统，同时与当前技术相比将传输线数量减少50倍。作为MRI兼容材料的新型主动冷却导管，我们的方法将产生一种多功能的血管内3D ICE导管，可以在常规X射线和MRI下操作。将通过体外和体内研究对3D MRICE和基于GPU的定制实时成像系统进行系统性评价，特别强调MRI安全性，并在第3年年底进行I期IDE临床试验。如果成功，我们的工作将解决一个关键的未满足的需求，并从根本上提高复杂心脏病的图像引导导管治疗，以提高有效性和结果。

DESCRIPTION (provided by applicant): Symptomatic adult and pediatric structural heart disease affects more than 2.9% of the US population, not including cardiomyopathies and rhythm disorders. Although nonsurgical approach is the preferred route for relief of symptoms, even common procedures such as atrial septal defect closure can be difficult, protracted, or unsuccessful because of limitations not only in available catheter devices but also because of inadequate image guidance. Current 2D and limited-volume 3D intracardiac ultrasound catheters do not provide suitable full-volume en face images to depict complex cardiac structures in real time, do not depict real-time navigation of catheters, and require adjunctive X-ray guidance. Miniaturization of ultrasound probes to provide uninterrupted real-time full-volume intra-procedural 3-dimensional en-face depiction of cardiac pathology and catheter devices would represent a dramatic advance in image-guided intervention. Further, design of a 3D ICE probe from inception to operate safely during MRI as well as during conventional X-ray would dramatically advance or even revolutionize the capabilities of transcatheter therapy by enabling completely radiation-free non-surgical catheter navigation. Our proposal aims to realize such a catheter, the 3D MRICE, based on the close collaboration of two groups at NHLBI and at Georgia Tech, and the unique resources available at the NIH Clinical Center for catheter fabrication, preclinical evaluation, and clinical trials. We use CMUT-on-CMOS technology and massive parallel RF data multiplexing to implement an ultra- miniature, single chip volumetric ultrasound imaging system while reducing the transmission line count by 50x compared with current technology. Implemented as a novel actively cooled catheter of MRI-compatible materials, our approach will produce a versatile intravascular 3D ICE catheter that can operate under conventional X-ray and MRI. The 3D MRICE and custom, GPU based real-time imaging system will be evaluated systematically through in-vitro and in-vivo studies with special emphasis on MRI safety leading to a an Phase I IDE clinical trial at the end of year 3. If successful, our work will address a key unmet need and fundamentally enhance image-guided catheter treatments of complex heart disease to improve effectiveness and outcome.