Spatio-temporal image correlation (STIC): Innovative 3D/4D technique for illustrating unique and independent information and diagnosing complex congenital heart diseases

Aim To assess whether four-dimensional (4D) spatiotemporal image correlation (STIC) can provide unique and novel information for diagnosing complex congenital heart diseases. Methods A dynamic interactive 4D ultrasound system was used to examine 21 fetuses with complex congenital heart diseases and 25 fetuses with no apparent anomalies referred for prenatal diagnosis and management. Data acquisition was achieved by an automatic sweep device capable of image capture across the entire fetal heart and thorax. An offline analysis of the acquired volume was carried out to examine the fetal cardiac anatomy with multiplanar mode and surface rendering. A simplified 'spin" technique was used to evaluate the outflow tracts of the fetal heart. Results Successful acquisition was possible in all 46 fetuses. STIC volume datasets were displayed interactively as a series of 3 orthogonal planes, with the ability of the examiner to control the pivot point, rotational axis, and parallel shift of each image plane inside the volume. The reformatted slices or surface-rendered images allowed the visualization of certain structures and projections not demonstrated with conventional fetal echocardiography. The information derived from STIC was either beneficial (8 patients) or crucial (5 patients) for establishing the diagnosis of congenital heart diseases in the study group. Conclusions This study demonstrated that the 4D STIC could provide unique and independent information from the routine use of fetal echocardiography that served for diagnosis of complex congenital heart diseases.