OC5.07: Comparison of 3D power Doppler ultrasound (3D‐PDU) versus 3D with Inversion mode rendering in 3D fetal echocardiography

Abstract

3D-PDU is an established technique in the assessment of the fetal cardiovascular system. The new “inversion mode (IM) rendering” enables without the use of Doppler to “invert” the hypoechoic informations in the volume box to a solid-like structure. We aimed to compared the accuracy of both techniques in 3D fetal echocardiography. 25 normal fetuses and 15 fetuses with various cardiac anomalies were examined between 20–30 weeks with both techniques. Presets were adapted individually according to the visualization conditions. Volumes were acquired in 3D static or in STIC (off-line 4D) technique. (GE-Voluson 730 Expert System). The evaluation was performed on an using the 4D-View software. Basic image quality was better with gray scale with a high image frame rate (80–110 Hz), vs PDU with slow rate (12–32 Hz). Time for presets optimisation was shorter for gray-scale in comparison to PDU image. Although on normal and abnormal hearts both techniques were similar in visualizing the heart and great vessels, this was easier and more accurately achieved using IM. IM was furthermore superior in visualizing tiny cardiac vessels in malformations, especially in unfavourable position. Power Doppler was superior in the demonstration of very small vessels and flow not seen on 2D as e.g. pulmonary veins, aberrant aortic arch vessels, muscular VSD or tricuspid regurgitation. Limitation of PDU was the overlapping of flow information, whereas the limitation of IM were the artefacts caused from shadowing (ribs, spine). The relationship to other thoracic structures was only possible in 3D-PDU glass body mode. 3D-IM technique is an easy accessible tool in 3D fetal echo. In regions with tiny vessels or in cases with hemodynamic events, power Doppler can be a complementary technique. The difficult preset optimisation and the low frame rates are still the main limitations of 3D-PDU.