MRI-safe 3Dl intracardiac ultrasound catheter for cardiovascular intervention

描述(申请人提供)：有症状的成人和儿童结构性心脏病影响超过2.9%的美国人口，不包括心肌病和节律紊乱。虽然非手术方法是缓解症状的首选途径，但由于现有导管装置的限制，以及影像指导不足，即使是房间隔缺损封堵术等常见的手术也可能困难、旷日持久或不成功。目前的2D和有限体积3D心内超声导管不能提供合适的全容量正面图像来实时描绘复杂的心脏结构，不能描绘导管的实时导航，并且需要辅助X射线引导。超声探头小型化以提供心脏病理和导管装置的不间断实时、全容量、术中三维正面描绘将代表着图像引导介入的巨大进步。此外，3D ICE探头的设计从一开始就可以在核磁共振成像和常规X射线期间安全操作，通过实现完全无辐射的非手术导管导航，将极大地促进甚至革命性地提高经导管治疗的能力。我们的建议旨在实现这样一种导管，即3D MRACE，基于NHLBI和佐治亚理工学院两个小组的密切合作，以及NIH临床中心可用于导管制造、临床前评估和临床试验的独特资源。我们利用CMUT-on-CMOS技术和大规模并行射频数据多路传输技术实现了一个超小型、单芯片体积超声成像系统，同时与现有技术相比减少了50倍的传输线数量。作为一种由MRI兼容材料制成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。我们将通过体外和体内研究对3D MRACE和定制的基于GPU的实时成像系统进行系统评估，重点是MRI的安全性，并将于第三年年底进行一期IDE临床试验。如果成功，我们的工作将满足一个关键的未得到满足的需求，并从根本上加强对复杂心脏病的图像引导导管治疗，以提高疗效和结果。

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.