673: The first trimester fetal heart–accurately accessible by 3D ultrasound

Evaluate standardized application of 3D ultrasound techniques for consistent and accurate display of fetal cardiac structure in the first trimester. We assessed the fetal heart in low risk women at 11-14 weeks following normal 1st trimester screening (normal Nuchal Translucency, nasal bone present, no tricuspid regurgitation, normal ductus venosus flow) in this sequence: 1. Identify the four-chamber view (4CV) 2. Obtain 3D volume with spatio-temporal image correlation (STIC) and color Doppler imaging (CDI) (angle=20 degrees, sweep 10sec). 3. Off-line, perform tomographic ultrasound imaging (TUI) as follows: Set slice number to 15, 4CV is the index slice; slice thickness is 0.5 to 2.0mm, defined by visualization of transverse aortic arch in slice +7. 4. Assess fetal heart anatomy [4CV, cardiac axis, size and symmetry concordant atrioventricular (AV) valves and great arteries (GA), descending aorta (DAo)]. 75 consecutive consenting women were 16-41 years old with body mass index 17.2 to 49.6. 3D acquisition (2-9 blocks per study) did not extend scanning time of any case.Fetal motion artifact required acquisition of >3 blocks in only 20%. Median time for TUI analysis was 100 sec (60 – 240). Individual anatomic landmarks were identified in 92-100% All structures were visualized in 63 (84%).FIGURE shows % success for exam components. Starting with a simple 2D landmark – the four chamber view – the standardized first trimester STIC-TUI technique enables expert cardiac evaluation