The value of two-dimensional ultrasound combined with three-dimensional spatio-temporal image correlation (STIC) in the diagnosis of fetal heterotaxy syndrome

Objective To evaluate the diagnostic accuracy and integrity of two-dimension ultrasound (2DUS) assisted with spatio-temporal image correlation (STIC) for cardiac and vascular abnormalities in fetal heterotaxy syndrome (HS). Methods The retrospective study was conducted from Nov 2007 to Feb 2013. Forty-five fetuses with suspected heterotaxy syndrome on routine prenatal ultrasonic screening underwent STIC volume sweep.The diagnosis was confirmed by pathological or echocardiographic examination. STIC volume data sets of fetal hearts were off-line analyzed blindly by one doctor who had practiced fetal echocardiography for more than five years. The concordance and integrity levels of diagnosis with 2DUS or assisted with STIC were compared according with pathological results. Results There were 397 cardiac and vascular defects in 37 cases of right isomerism. The overall concordance of various defects in right isomerism diagnosed assisted with STIC (96.5%) was significantly higher than that of 2DUS (60.2%)(P 0.05). There was no significant difference in concordance rates of various defects of left isomerism diagnosed between two methods, except that the concordance rate of left atria isomerism diagnosed assisted with STIC was higher(P<0.05). There was no difference in percentages of diagnostic integrity levels (0-3) in left isomerism between two methods. Conclusions STIC technology may provide considerable diagnostic information for ultrasonic diagnosis of fetal heterotaxy syndrome, especially in abnormalities of atria and ventricle isomerism, ventriculo-arterial junction, arterial arches, systematic and pulmonary veins in right isomerism. Key words: Ultrasonograhy, prenatal; Heart defects, congenital; Heterotaxy syndrome; Spatio-temporal image correlation