Effects of medical imaging examinations for diagnosis of pulmonary artery sling before and after delivery

Abstract

Objective To study effects of medical imaging examinations for diagnosis of children pulmonary artery sling (PAS) before and after delivery. Methods From January 2017 to January 2019, a total of 4 children with PAS who were diagnosed by undergoing cardiac surgery in West China Second University Hospital, Sichuan University were selected into this study. Data of medical imaging examinations and clinical manifestations of 4 children with PAS, including fetal echocardiogram, fetal MRI, pediatric echocardiogram and multi-slice spiral CT angiography were analyzed retrospectively. This study was in line with the requirements of World Medical Association of Helsinki revised in 2013. Results ①Fetal echocardiogram detected difference of long axis section of pulmonary artery, three blood vessels section and three blood vessel-trachea section. The main ultrasonic signs were bifurcation structure of the pulmonary artery disappeared, abnormal left pulmonary artery originated from the right pulmonary artery, the left pulmonary artery traced behind the trachea forming C shaped vascular ring. And secondary ultrasonic sign was diameter of the left pulmonary artery was smaller than that of the right pulmonary artery. ② Fetal cardiac MRI revealed the left pulmonary artery arising from the right pulmonary artery and going behind the trachea in the pulmonary artery trunk level. ③ Detections by pediatric echocardiogram were short axis section of the great artery, and its main ultrasonic signs were bifurcation of pulmonary artery disappeared, as well as abnormal left pulmonary artery originated from the right pulmonary artery. ④ Main manifestations of multi-slice spiral CT angiography in children revealed that the left pulmonary artery originated from the right pulmonary artery and traced behind the trachea, and the trachea was compressed. Conclusions Diagnosis of fetal PAS mainly depends on fetal echocardiogram, fetal cardiac MRI can provide supplementary diagnosis for ultrasound. Diagnosis of PAS children should be comprehensive evaluation by pediatric echocardiogram, multi-slice spiral CT angiography and other imaging methods. Key words: Pulmonary artery sling; Ultrasonography, prenatal; Echocardiography; Multi-slice spiral CT; Magnetic resonance imaging; Fetus