Lee Wai-Kit, Mossop Peter J, Little Andrew F, Fitt Gregory J, Vrazas Jhon I, Hoang Jenny K, Hennessy Oliver F
Department of Medical Imaging, St Vincent's Hospital, University of Melbourne, Fitzroy, Victoria, Australia.
Radiographics. 2008 Nov-Dec;28(7):1853-68. doi: 10.1148/rg.287085054.
Infected aneurysms are uncommon. The aorta, peripheral arteries, cerebral arteries, and visceral arteries are involved in descending order of frequency. Staphylococcus and Streptococcus species are the most common causative pathogens. Early clinical diagnosis of infected aneurysms is challenging owing to their protean manifestations. Clinically apparent infected aneurysms are often at an advanced stage of development or are associated with complications, such as rupture. Nontreatment or delayed treatment of infected aneurysms often has a poor outcome, with high morbidity and mortality from fulminant sepsis or hemorrhage. Current state-of-the-art imaging modalities, such as multidetector computed tomography and magnetic resonance imaging, have replaced conventional angiography as minimally invasive techniques for detection of infected aneurysms in clinically suspected cases, as well as characterization of infected aneurysms and vascular mapping for treatment planning in confirmed cases. Doppler ultrasonography allows noninvasive assessment for infected aneurysms in the peripheral arteries. Imaging features of infected aneurysms include a lobulated vascular mass, an indistinct irregular arterial wall, perianeurysmal edema, and a perianeurysmal soft-tissue mass. Perianeurysmal gas, aneurysmal thrombosis, aneurysmal wall calcification, and disrupted arterial calcification at the site of the infected aneurysm are uncommon findings. Imaging-guided endovascular stent-graft repair and embolotherapy can be performed in select cases instead of open surgery. Familiarity with the imaging appearances of infected aneurysms should alert the radiologist to the diagnosis and permit timely treatment, which may include endovascular techniques.
感染性动脉瘤并不常见。主动脉、外周动脉、脑动脉和内脏动脉受累的频率依次递减。葡萄球菌和链球菌是最常见的致病病原体。由于感染性动脉瘤表现多样，其早期临床诊断具有挑战性。临床上明显的感染性动脉瘤往往处于疾病发展的晚期，或伴有诸如破裂等并发症。感染性动脉瘤若不治疗或延迟治疗，通常预后不佳，因暴发性脓毒症或出血导致高发病率和死亡率。当前的先进成像方式，如多排螺旋计算机断层扫描和磁共振成像，已取代传统血管造影，成为临床上疑似病例中检测感染性动脉瘤以及确诊病例中对感染性动脉瘤进行特征描述和用于治疗规划的血管造影的微创技术。多普勒超声检查可对外周动脉的感染性动脉瘤进行无创评估。感染性动脉瘤的影像学特征包括分叶状血管肿块、动脉壁不规则且边界不清、动脉瘤周围水肿以及动脉瘤周围软组织肿块。动脉瘤周围气体、动脉瘤血栓形成、动脉瘤壁钙化以及感染性动脉瘤部位的动脉钙化中断则为不常见表现。在某些病例中，可采用影像引导下的血管内支架植入修复术和栓塞治疗来替代开放手术。熟悉感染性动脉瘤的影像学表现应能使放射科医生警觉到该诊断并及时进行治疗，治疗可能包括血管内技术。
