Magnetic Resonance Imaging Near Metallic Implants

描述（由申请人提供）：本项目的目标是解决磁共振成像（MRI）在评价植入金属植入物的患者时的基本局限性。我们将开发一个完整的三维失真校正成像和重建技术，提供诊断图像没有金属诱导的伪影。我们还将提供不同的对比机制，用于近金属成像。所有技术将在尸体模型和植入脊柱植入物的受试者体内进行确认。相关性：MRI被广泛认为是骨科疾病的最佳成像方式，如骨髓炎、血管坏死、肌腱或韧带损伤、骨或软组织病变、脊神经根压迫和椎管狭窄。不幸的是，在具有金属植入物的患者中，MRI受到金属诱导伪影的阻碍（例如，严重的信号损失、失真），以及在植入物附近的位置处的脂肪抑制失败。这些正是可能发生术后并发症的位置，因此准确的成像可能具有最大的临床影响。方法：本项目解决了在金属植入物附近进行MRI的这些技术挑战。我们的方法是开发新的脉冲序列，不需要额外的硬件，可以在1.5T MRI系统的大型安装基础上使用。具体而言，我们的目标是（1）开发3D成像方法以消除所有金属诱导的伪影，（2）在金属存在的情况下开发更强大的脂肪抑制，以及（3）在尸体研究中评估我们的成像方法，随后对12名既往接受过脊柱植入物的患者进行研究。在资助期结束时，我们将开发出提供无失真图像和金属植入物附近强大脂肪抑制的方法。该项目的成功将改善数百万患者的诊断和治疗。公共卫生相关性：金属植入物越来越多地用于治疗脊柱、髋关节和膝关节的慢性和急性损伤。磁共振成像（MRI）通常用于评估骨科疾病，但由于金属引起的严重磁场不均匀性，在金属植入物附近无法使用。该研究项目将开发完整的3D校正金属引起的失真，从根本上改善植入物附近的MRI。

DESCRIPTION (provided by applicant): The goals of this project are to address the fundamental limitations of magnetic resonance imaging (MRI) in evaluating patients with metallic implants. We will develop a complete 3D distortion- corrected imaging and reconstruction technique that provides diagnostic images without metal-induced artifacts. We will also provide different contrast mechanisms for imaging near metal. All the techniques will be validated in a cadaveric model and in vivo in subjects with spinal implants. Relevance: MRI is widely regarded as the best imaging modality for orthopedic conditions such as osteomyelitis, a vascular necrosis, tendon or ligamentous injury, bone or soft tissue lesions, spinal nerve root compression, and spinal stenosis. Unfortunately, in patients with metallic implants, MRI is hampered by metal-induced artifacts (e.g., severe signal loss, distortions), and failure of fat suppression at the locations near the implants. These are precisely the locations where post-surgical complications are likely to occur, and thus where accurate imaging could have the greatest clinical impact. Approach: This project addresses these technical challenges of performing MRI near metallic implants. Our approach is to develop new pulse sequences that require no additional hardware and can be utilized on the large installed base of 1.5T MRI systems. Specifically, we aim to (1) develop 3D imaging methods to eliminate all metal-induced artifacts, (2) develop more robust fat suppression in the presence of metal, and (3) evaluate our imaging methods in a cadaver study, followed by a study of 12 patients who have previously received spinal implants. At the end of the funding period, we will have developed methods that provide distortion- free images and robust fat suppression near metallic implants. The success of this project will improve the diagnosis and treatment of millions of patients. PUBLIC HEALTH RELEVANCE: Metallic implants are being used increasingly to treat chronic and acute injuries to the spine, hip and knee. Magnetic resonance imaging (MRI) is commonly used for evaluating orthopedic conditions, but fails near metallic implants due to severe magnetic field inhomogeneities caused by metal. This research project will develop complete 3D correction of metal-induced distortions to radically improve MRI near implants.