OP16.13: Clinical combining‐application of ultrasound and MRI on multiplets malformations

Objectives: To explore the diagnostic value of antenatal ultrasound combining with in utero magnetic resonance imaging (MRI) in multiplets malformations, and analyze their advantages and limitations. Methods: In the period between 2004 and 2007, 105105 fetuses received ultrasound examination in our hospital. 268 cases were multifetation, including 64 multiplets malformations. And of them 11 multiplets malformations (gestational age ranged from 14–31 weeks), including 8 cases of twin pregnancy and 3 of triplet pregnancy, received MRI examination within 48 hours after ultrasound, all confirmed by autopsy. Retrospectively analyzed, the results of antenatal ultrasound and in utero MRI were compared. Results: In 11 multiplets malformations, there were 6 conjoined twins and 5 acardiac twins with twin-reversed arterial perfusion (TRAP). MRI gave identical diagnostic results with ultrasound, but each had different advantages. (1) MRI was superior to ultrasound in the following aspects: 1. the large view with visualization 2 or 3 fetal organs, even the whole fetus, placenta and amniotic sac simultaneously; 2. visualizing diprosopy of cephalopagus and identifying complex intracranial structures clearly; 3. identifying internal organs of conjoined twins; 4. demonstrating the insertion of umbilical core and the connection with fetus and placenta in acardiac twin.; 5. It showed ‘‘leopard stripe sign’’ in placenta of acardiac twin. (2) Ultrasound was superior to MRI in two aspects: 1. detecting hemodynamic change in TRAP; 2. evaluating cardiac function and finding cardiac anomalies, such as hemicardia of acardiac twin. Conclusions: Ultrasound and MRI are complement with each other in diagnosing multiplets malformations, The combining application of ultrasound and MRI could improve the diagnostic accuracy on multiplets malformations