Evaluation of fetal congenital persistence of the left superior vena cava using fetal MR

Results The 58 cases of fetal LSVC detected by fetal MRI represents 1.23% of all fetal MRI examinations performed in our hospital (58/4726). All the 58 cases were correctly diagnosed by MR imaging but only 40 cases (69%) were correctly diagnosed by fetal ultrasound. Of the 18 cases which did not be correctly diagnosed by fetal ultrasound, 8 were sent to perform fetal MRI for head or chest malformation. Before fetal MRI they only did general fetal ultrasound and never did fetal echocardiography. 9 did fetal echocardiography before fetal MRI. But the doctors are from small hospital and no enough experience. Only one case which did not be correctly diagnosed was performed fetal echocardiography by experienced doctors and this case first time performed fetal echocardiography was at 34 weeks gestation. After the fetal cardiac MRI examination, all the 18 cases were performed fetal echocardiography again and all can find persistent LSVC. In the 40 cases correctly diagnosed by fetal ultrasound, two cases LSVC were correctly diagnosed using fetal echocardiography by experienced doctors but fetal MRI found bridging vessels which did not found by echocardiography. In another two cases (not include the 58 cases) LSVC was diagnosed by fetal echocardiography but fetal cardiac MRI found it was really a retroesophageal left brachiocephalic vein.