肺血流灌注显像右向左分流的鉴别诊断

The differentiation of the right-to-left shunt in lung perfusion imaging

目的:探讨肺灌注显像呈右向左分流的病因和鉴别诊断。方法:27例紫绀患儿行肺灌注显像、心脏彩超、核磁共振和/或心导管检查,回顾性分析其影像学表现。结果:27例患儿的肺灌注显像除肺组织显影外均出现不同程度的脑、肾和/或脾脏显影,22例存在心脏的解剖发育异常;5例表现为肺内弥漫性动静脉瘘,其中2例为原发性肺内血管异常,1例合并先天性门静脉-下腔静脉侧支形成,1例伴有血吸虫肝硬化史,1例有食管静脉曲张、呕血及肝硬化史。结论:肺灌注显像右向左分流主要见于解剖发育异常的先天性心脏病,原发性肺动静脉瘘及肝脏疾病所致的肝硬化、肝肺综合征亦可导致肺外组织脏器显影。

Objective：To study the etiologies and differentiations of the right-to-left shunt in lung perfusion imaging. Methods：Twenty-seven children with cyanosis, who underwent lung perfusion imaging, echocardiography, magnetic reso- nance imaging and/or cardiac catheterization were collected. The imaging features were retrospectively analyzed. Results：In addition to the uptake of the lungs,increased uptake of SSmTc-MAA was also noted in brain,spleen,and kidneys in all pa- tients. Twenty two patients had anatomic abnormalities within the heart. Five patients had multiple arteriovenous fistulas in lungs. Of the five cases,two had primary pulmonary vascular abnormalities;one had a congenital bypass between portal vein and inferior vena cava;one had schistosomal cirrhosis, and one had liver cirrhosis with esophageal varices and a history of hematemesis. Conclusions：In lung perfusion imaging, right-to-left shunt was more commonly seen in the congenital heart disease with anatomic abnormalities and pulmonary arteriovenous fistulas. Liver cirrhosis due to varying conditions and hep- atopulmonary syndrome can also lead to an increased uptake of 99mTc-MAA in extrapulmonary organs.