Realtime 3D MRI Technologies for Therapy and Diagnosis

描述(申请人提供)：癌症患者的生活质量和生存受到肝转移的严重威胁。虽然手术切除通常是不可能的，全身化疗在很大程度上是无效的，但有希望的介入治疗技术是可用的。本项目的重点是展示实时时间分辨3D MR引导对其中一种技术的有效性：经导管动脉化疗栓塞术(TACE)。该项目的成功完成不仅将使TACE程序立即得到改进，而且应该为融合局部血管和解剖信息的其他药物输送技术奠定坚实的基础。目前X射线数字减影血管造影术(DSA)对TACE的指导提供了厚厚的2D投影图像，几乎没有关于肿瘤位置的信息，同时增加了肝脏肿瘤患者接受的本已很高的电离辐射剂量。虽然磁共振成像提供3D功能已经有一段时间了，但要将实时3D MRI应用到新的问题上，还需要在采集速度、重建处理和可视化方面进一步改进。挑战源于4D成像产生的数据量的异常增长。但是，MRI中并行成像的快速发展、使用MR的多种对比机制的新范式以及计算能力的持续显著提高带来了机遇。该项目旨在开发4D MRI，三维空间加时间，以更好地显示肿瘤周围血管的结构和意义，并将其与TACE所需的其他介入性成像方法相结合。具体地说，该项目的前两个具体目标集中在重建和可视化方面：1)使用更快、更有效的非笛卡尔技术来提高MR成像的速度和覆盖率，并将这些技术集成到一个实时重建平台中；2)使用计算机集群来可视化4D数据。第三个目标是将这些发展与MR引导所需的其他功能相结合，包括导管可视化和病变明显的3D T2加权成像。最后一个目标是使用与验证临床TACE相同的方法来验证这些能力。成功完成将提供必要的信息，以支持稍后的人体试验，并为指导TACE和一般药物输送提供一个平台。前两个目标的结果也将缩短采集时间，改善图像质量，并简化时间分辨诊断性磁共振血管成像的解释。

DESCRIPTION (provided by applicant): The quality of life and survival for cancer patients are considerably threatened by liver metastases. While surgical resection is often not possible and systemic chemotherapy is largely ineffective, promising interventional therapeutic techniques are available. The focus of this project is to demonstrate the effectiveness of real-time time-resolved 3D MR guidance for one such technique: transcatheter arterial chemoembolization (TACE). Successful completion of the project will not only allow immediate improvement of TACE procedure, but should prove to be a capable foundation for other drug delivery techniques where fusing information of local vasculature and anatomy is beneficial. Current guidance for TACE from X-ray Digital Subtraction Angiography( DSA) provides thick 2D projection images with little information on tumor location while increasing the already high dose of ionizing radiation received by liver tumor patients. While MR imaging has provided 3D capabilities for some time, further improvements in acquisition speed, reconstruction processing, and visualization are necessary to apply real-time 3D MRI to new problems. Challenges are derived from the extraordinary increase in data created by 4D imaging. But opportunities are derived from the rapid development of parallel imaging in MRI, new paradigms for using MR's multiple contrast mechanisms, and the continued dramatic improvement in computing power. This project aims to develop 4D MRI, three spatial dimensions plus time, to better visualize the structure and significance of the vasculature adjacent to tumors, and integrate it with the other interventional imaging methods necessary for TACE. Specifically, the first two specific aims of this project concentrate on reconstruction and visualization: 1) Improve MR imaging speed and coverage using faster, more efficient non-Cartesian techniques and integrating these into a real-time reconstruction platform and 2) visualizing of 4D data using a computer cluster. The third aim integrates these developments with other capabilities necessary for MR guidance including catheter visualization and 3D T2-weighted imaging for lesion conspicuity. The last aim verifies these capabilities using the same methods used to validate clinical TACE. Successful completion will provide the necessary information to support a later human trial and a platform for guiding TACE as well as drug delivery in general. Outcomes for the first two aims will also shorten acquisition time, improve image quality, and simplify interpretation of time-resolved diagnostic MR angiography.