免疫抑制后肺部机会性感染的影像诊断

Imaging diagnosis of pulmonary opportunistic infections in Immunosuppressed patients

艾滋病的流行、器官移植、免疫抑制剂的大量使用均可导致病人的免疫系统严重受损，而并发肺部机会性感染是这些免疫抑制病人的主要临床问题。影像在诊断和治疗这类病人中起着重要作用。本文主要讨论肺部机会性感染的胸片及CT诊断。肺部机会性感染是HIV／AIDS的主要并发症，由多种病因引起。成人HIV／AIDS肺部感染最常见的类型为肺结核、肺孢子虫肺炎和细菌性肺炎。由于抗排异反应药物及免疫抑制荆的应用，导致器官移植的病人机体免疫功能严重受抑，最主要的病因是巨细胞病毒。侵袭性霉菌病几乎都发生在白细胞严重减少的免疫抑制病人。慢性疾病病人免疫中度受损时，易发生特有的霉菌病，称半侵袭盛慢性坏死性霉菌病。在肺部机会性感染病人的诊断和治疗中，放射科医生起了很重要的作用。然而影像学表现都不具特异性，但合理选择成像方法，密切结合临床和流行病学等对肺部机会性感染的诊断、病情评估和预后具有重要意义。

AIDS epidemic, organ transplantation, and immunosuppressive therapy has resulted in large numbers of patients who develop abnormalities in their immune system. Opportunistic infections of lung are a major clinical problem for immunosuppressed patients, lmaging diagnosis plays a crucial role in the detection and management of patients with pneumonia. This review article discusses the different imaging methods used in the diagnosis and management of suspected pulmonary infections. In AIDS patients, opportunistic infections of lung may result from a variety of pathogens. The most common patterns are Tuberculosis, bacterial pneumonia and Pneumocystis carinii pneumonia. Patients undergoing transplantation present increased susceptibility to opportunistic infection. The most important pathogen affecting transplant recipients is CMV. Invasive aspergiUosis occurs almost exclusively in immunoeompromised patients with a severe neutropenia. Mildly immunoeompromised patients are prone to develop a distinct form of aspergillus infection called semiinvasive or chronic necrotizing aspergillosis, in conclusion, the radiologist plays an important role in the diagnosis and management of patients with ,suspected these pneumonias. The radiographic pattern is very different among persons with immunodeficiency. Integrating imaging findings with clinical data will enhance the accuracy of the radiographical diagnosis.