Visualization of the atrioventricular valve plane in fetuses with atrioventricular defect using STIC technique

C. Ionescu, D. Gheorghiu, B. Davitoiu, I. Pacu, T. Vlădescu

Abstract: To asses the feasibility of Spatio-temporal image correlation (STIC) -rendering and Spatio-temporal image correlation with Tomographic ultrasound image (STIC-TUI) acquisition of the AV plane in normal fetuses and in fetuses with atrioventricular septal defect (AVSD), and to ascertain whether these planes add useful information in fetal cardiac examination. 60 ultrasound exams in normal fetuses and 5 exams for fetuses with complete atrioventricular septal defect were performed; the volumes were acquired in apical or lateral four-chamber view of the heart, with STIC-rendered and STIC-TUI acquisition. In the STIC-rendered acquisition, the render box was placed either with the render view direction in the atria at the level of the valves (the en-face view of the atrioventricular valves and semilunar valves), either with the render view direction in the ventricles close to the atrioventricular plane. Afterwards the volume acquired in apical or lateral (preferably in apical) view was set with STIC-TUI acquisition and the distance between slices was adjusted finally until an optimal analysis was possible. The acquisition of the cardiac volume with STIC-rendered was possible in 93,8% cases and with STIC-TUI is possible in all cases. In normal cases, with STIC-rendering acquisition we can show the position of the papillary muscle at the level of the left and right ventricle. In complete AVSD cases the common atrioventricular valve can be seen with five leaflets. A sequential segmental analysis of the fetal heart could be shown with STIC-TUI in all cases. The both modalities improved visualization of the AV plane and diagnosing the defects at this level, improves also the evaluation of the AV annuli in relation with the major vessels. The volume acquisition of the atrioventricular plane with STICrendering and STIC-TUI modalities allows visualization of the images that are not easily accessible with standard 2D sonography, enabling a rapid assessment of the normal and abnormal fetal cardiac structure, respectively AVSD.
Keywords: atrioventricular septal defect, congenital heart disease, spatiotemporal image correlation, tomographic ultrasound image