Chandekar Kunal R, Satapathy Swayamjeet, Singh Harmandeep, Bhattacharya Anish
Department of Nuclear Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India.
World J Radiol. 2022 Jul 28;14(7):194-208. doi: 10.4329/wjr.v14.i7.194.
Coronavirus disease 2019 (COVID-19) is caused by the novel viral pathogen, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). COVID-19 primarily involves the lungs. Nucleic acid testing based on reverse-transcription polymerase chain reaction of respiratory samples is the current gold standard for the diagnosis of SARS-CoV-2 infection. Imaging modalities have an established role in triaging, diagnosis, evaluation of disease severity, monitoring disease progression, extra-pulmonary involvement, and complications. As our understanding of the disease improves, there has been substantial evidence to highlight its potential for multi-systemic involvement and development of long-term sequelae. Molecular imaging techniques are highly sensitive, allowing non-invasive visualization of physiological or pathological processes at a cellular or molecular level with potential for detection of functional changes earlier than conventional radiological imaging. The purpose of this review article is to highlight the evolving role of molecular imaging in evaluation of COVID-19 sequelae. Though not ideal for diagnosis, the various modalities of molecular imaging play an important role in assessing pulmonary and extra-pulmonary sequelae of COVID-19. Perfusion imaging using single photon emission computed tomography fused with computed tomography (CT) can be utilized as a first-line imaging modality for COVID-19 related pulmonary embolism. F-fluorodeoxyglucose positron emission tomography (PET)/CT is a sensitive tool to detect multi-systemic inflammation, including myocardial and vascular inflammation. PET in conjunction with magnetic resonance imaging helps in better characterization of neurological sequelae of COVID-19. Despite the fact that the majority of published literature is retrospective in nature with limited sample sizes, it is clear that molecular imaging provides additional valuable information (complimentary to anatomical imaging) with semi-quantitative or quantitative parameters to define inflammatory burden and can be used to guide therapeutic strategies and assess response. However, widespread clinical applicability remains a challenge owing to longer image acquisition times and the need for adoption of infection control protocols.
2019冠状病毒病（COVID-19）由新型病毒病原体严重急性呼吸综合征冠状病毒2（SARS-CoV-2）引起。COVID-19主要累及肺部。基于呼吸道样本逆转录聚合酶链反应的核酸检测是目前诊断SARS-CoV-2感染的金标准。影像学检查在分诊、诊断、疾病严重程度评估、监测疾病进展、肺外累及情况及并发症方面发挥着既定作用。随着我们对该疾病认识的提高，有大量证据凸显了其多系统累及及长期后遗症发生的可能性。分子成像技术高度灵敏，能够在细胞或分子水平对生理或病理过程进行无创可视化，比传统放射影像学更早检测到功能变化。本文综述的目的是强调分子成像在评估COVID-19后遗症方面不断演变的作用。尽管分子成像并非诊断的理想手段，但它的各种模式在评估COVID-19的肺部和肺外后遗症方面发挥着重要作用。使用单光子发射计算机断层扫描与计算机断层扫描（CT）融合的灌注成像可作为COVID-19相关肺栓塞的一线成像手段。F-氟脱氧葡萄糖正电子发射断层扫描（PET）/CT是检测包括心肌和血管炎症在内的多系统炎症的灵敏工具。PET与磁共振成像相结合有助于更好地明确COVID-19的神经后遗症特征。尽管大多数已发表的文献本质上是回顾性的且样本量有限，但很明显分子成像提供了额外有价值的信息（作为解剖成像的补充），通过半定量或定量参数来界定炎症负荷，可用于指导治疗策略并评估疗效。然而，由于图像采集时间较长以及需要采用感染控制方案，其广泛的临床适用性仍然是一项挑战。
