Improved Targeting and Assessment of Electrophysiology Intervention

描述（由申请人提供）：心房颤动（AF）和室性心动过速（VT）在美国影响数百万患者。这些心律失常可以通过导管消融术治愈，但心律失常经常复发。消融后房颤复发率超过30%的主要原因是无法确认消融病灶在预期位置的存在。当前消融技术的其他局限性包括：(1)难以将导管精确定位，难以准确放置消融；(2)缺乏充分预测静脉血栓通过疤痕的途径的能力，而疤痕是消融的目标。我们正在开发将磁共振成像（MRI）和计算机断层扫描（CT）的解剖信息与导管消融相结合的方法，以进行先进的实时图像引导干预。然而，目前尚不清楚MRI和CT孰优孰劣。这两个项目都包含在这个项目中，因为许多正在开发的技术可以与MRI和CT一起使用。我们假设MRI和/或CT的高分辨率成像，配合兼容的电极导管、导管尖端位置传感器、远程控制导管操纵器、实时扫描仪控制、热成像和4维（3个空间维度加时间）成像软件可以(1)提供导管的精确导航，(2)提供滴定和确认所需位置消融病变的能力，(3)有助于生成更准确的电图。(4)有助于预测消除目标心律失常所需的消融程度。我们之前已经证明了以下方法的可行性：(1)实时MRI引导导管，(2)使用CT和MRI进行病变可视化，(3)疤痕中保存的心肌组织的高分辨率成像，以及(4)使用计算模型预测室速回路的位置。该建议涉及开发(1)改进的导管尖端位置传感器，(2)改进的实时扫描仪控制，(3)动态三维图像重建，使用叠加的导管尖端位置信息，(4)改进的高分辨率心肌成像，以便充分显示疤痕内保存的心肌的细节，(5)基于详细疤痕形态预测个体患者室速电路的计算模型。(6)改进了预测单个患者对消融反应的方法，(7)实时登记多模态信息的方法，包括电图和多图像，(8)MRI热成像，以帮助实时滴定和评估消融病变形成，(9)远程控制导管操纵器，以提高导管放置的准确性。我们将把这项技术应用于心房和室性心律失常患者的实时先进图像引导治疗，并有可能将其应用于一般的介入手术。该项目是约翰霍普金斯大学医学系、放射学系和生物医学工程系的合作项目；和工业合作伙伴（成本分担）：Irvine Biomedical（临床级导管），Hansen Medical（导管操作系统）和Imricor（导管组件）。

DESCRIPTION (provided by applicant): Atrial fibrillation (AF) and ventricular tachycardia (VT) affect millions of patients in the United States. These arrhythmias can be cured with catheter ablation, but the arrhythmias often recur. The inability to confirm the presence of ablated lesions in the desired locations is the major factor in the greater than 30 % recurrence of AF after ablation. Additional limitations of current ablation technology include: (1) difficulty in navigating catheters to exact locations, making it difficult to accurately place ablations, and (2) the lack of ability to adequately predict the pathways of VT through scar, which are the targets for ablation. We are developing ways of combining the anatomic information from magnetic resonance imaging (MRI) and computed tomography (CT), with catheter ablation, for performing advanced real-time image guided interventions. It is not known, however, whether MRI or CT will be superior for image guided interventions. Both are included in this project because a number of the technologies being developed can be used with both MRI and CT. We hypothesize that high resolution imaging with MRI, and/or CT, with compatible electrode catheters, catheter-tip location sensors, remote-controlled catheter manipulators, real-time scanner control, thermal imaging, and 4-dimensional (3 spatial dimensions plus time) imaging software can (1) provide for accurate navigation of catheters, (2) provide the ability to titrate and confirm the presence of ablated lesions in the desired locations, (3) aid in producing more accurate electrical maps, and (4) aid in predicting the extent of ablation needed to eliminate the target arrhythmia. We have previously demonstrated the feasibility of (1) real- time MRI guidance of catheters, (2) lesion visualization using CT and MRI, (3) high resolution imaging of preserved myocardial tissue in scar, and (4) using computational modeling to predict the location of VT circuits. This proposal deals with developing (1) improved catheter tip location sensors, (2) improved real-time scanner control, (3) dynamic 3-dimensional image reconstruction, with superimposed catheter tip location information, (4) improved high resolution imaging of myocardium so that details of preserved myocardium within scar can be adequately visualized, (5) a computational model that can predict the VT circuits in individual patients based on the detailed scar morphology, (6) improved methods for predicting individual patient's response to ablation, (7) methods for real-time registration of multimodal information, including electrical maps, and multiple images, (8) MRI thermography to aid in real-time titrating and assessing of ablation lesion formation, and (9) remote controlled catheter manipulators to improve the accuracy of catheter placement. We will apply this technology to real-time advanced image guided therapy in patients with atrial and ventricular arrhythmias, and potentially broaden its use to interventional procedures in general. This project is a partnership between the Johns Hopkins University Departments of Medicine, Radiology, and Biomedical Engineering; and industrial partners (with cost sharing): Irvine Biomedical (clinical grade catheters), Hansen Medical (catheter manipulation system), and Imricor (catheter components).