Quantitative periprosthetic PET/CT

描述（由申请人提供）：在美国目前每年进行的约350，000例关节置换术中，有相当多的患者需要提前翻修手术。疼痛植入物的最具挑战性的诊断方面之一是区分无菌性骨质溶解、对磨损碎屑浸润的炎症反应和关节周围组织的感染。目前的诊断技术，如普通X线摄影，实验室和核医学测试有严重的缺点。与此同时，感染诊断的失败会使翻修手术的结果急剧恶化，发病率和死亡率急剧增加，低估无菌性骨溶解的程度可能导致错误的翻修时机。计算机断层扫描（CT）和正电子发射断层扫描（PET）已被认为是潜在的诊断替代品，具有出色的灵敏度和特异性。然而，在存在金属植入物的情况下，CT遭受严重的图像伪影，这不仅使CT图像无法诊断，而且当使用现代多模态PET/CT设备获得PET数据时，对PET数据的可用性产生负面影响。在我们机构对专用成像体模进行的一项试点研究中，CT金属伪影的算法减少被证明对基于CT的无菌性骨质溶解诊断有效。这项研究的主要目的是将这项工作扩展到PET/CT，从而为无菌性骨质溶解和感染创造一种新型的一站式诊断工具。本提案的实验重点是构建骨质溶解和感染体模模拟器，以优化和测试我们的金属伪影减少算法，并在20例疼痛髋关节或膝关节假体患者的小型研究中测试组合PET/CT扫描比独立PET更有用的假设。此外，基于随访CT成像，我们将首次能够评估植入物附近无菌性骨质溶解的进展率。我们相信，一种新型的金属伪影校正PET/CT扫描将通过提供无菌性骨质溶解和感染的鉴别诊断来确保患者安全，并将有助于改善手术计划，避免误诊骨质溶解和感染，从而带来痛苦和昂贵的后果。公共卫生相关性：人工髋、膝关节置换术已成为治疗骨关节炎和其他关节疾病的一种非常成功的手术选择。由于接受这种治疗的患者数量众多，一小部分植入物发生疼痛性松动，导致大量患者需要接受翻修手术。正确诊断引起疼痛的并发症以确保最佳的患者管理和手术计划非常重要。我们建议克服与使用X射线计算机断层扫描对金属植入物成像相关的技术挑战，并将该技术与正电子发射断层扫描相结合，为早期诊断可能导致植入物失败的并发症提供一种新的综合工具。

DESCRIPTION (provided by applicant): Of the approximately 350,000 total joint replacements that are currently performed in the U.S. each year, a significant number will require premature revision operation. One of the most challenging diagnostic aspects of the painful implant is the differentiation between aseptic osteolysis, an inflammatory response to infiltration of wear debris, and infection of the tissue surrounding the joint. Current diagnostic techniques such as plain radiography, laboratory and nuclear medicine tests have severe shortcomings. At the same time, failed diagnosis of infection can dramatically worsen the outcome of a revision operation with sharply increased morbidity and mortality, and underestimation of the extent of aseptic osteolysis may lead to wrong timing of the revision. Both Computed Tomography (CT) and Positron Emission Tomography (PET) have been recognized as potential diagnostic alternatives with excellent sensitivity and specificity for both conditions. However, CT suffers from severe image artifacts in the presence of metallic implants that not only render the CT images undiagnostic but also negatively influence the usability of PET data when they are obtained with modern multimodality PET/CT equipment. In a pilot study at our institution on a dedicated imaging phantom, algorithmic reduction of CT metal artifact was shown to be effective for CT-based diagnosis of aseptic osteolysis. The main objective of the proposed research is to extend this work to PET/CT and thereby create a novel one-stop diagnostic tool for both aseptic osteolysis and infection. The experimental focus of this proposal is to build an osteolysis and infection phantom simulator to optimize and test our metal artifact reduction algorithms, and to test the hypothesis that a combination PET/CT scan is more useful than standalone PET in a small study of 20 patients with painful hip or knee prostheses. Furthermore, based on follow-up CT imaging we will for the first time be able to assess progression rates of aseptic osteolysis directly next to the implant. We believe that a novel metal artifact-corrected PET/CT scan will ensure patient safety by providing a differential diagnosis of both aseptic osteolysis and infection and will help improve surgical planning and avoid misdiagnosis of osteolysis and infection with its painful and costly consequences. PUBLIC HEALTH RELEVANCE: Joint replacement with artificial hips and knees has become a very successful surgical choice to treat osteoarthritis and other joint diseases. Because of the large number of patients so treated, the small fraction of implants that develop painful loosening results in a large rate of patients needing to undergo revision surgery. It is important to correctly diagnose the complication causing the pain to ensure optimal patient management and surgical planning. We propose to overcome the technical challenges associated with using X-ray computed tomography for imaging of metallic implants and use the technique in combination with Positron Emission Tomography to provide a novel comprehensive tool for the early diagnosis of the complications that would otherwise lead to implant failure.