3D/4D ultrasound in the diagnosis of significant hypoplasia of the left ventricle in hypoplastic left heart syndrome
Objective: to evaluate the value of 4D fetal heart ultrasound assessment of diastolic right : left ventricle volume ratio in diagnosis of significant hypoplasia of the left ventricle in hypoplastic left heart syndrome. Material and methods: the main group consisted of 21 fetuses with hypoplastic left heart syndrome, in which left ventricle length and end-diastolic dimension were equal or below the 5th percentile for gestational age. The control group consisted of 50 healthy fetuses. Prenatal ultrasound examination was performed at 18-21 weeks of gestation with the use of Voluson 730 Expert (GE Healthcare, USA) with Virtual Organ Computer-aided AnaLysis (VOCAL) and Spatio-Temporal Image Correlation (STIC) software with 4D convex transabdominal transducer (4-8.5 MHz). 4D volumes of the left and right ventricle in diastole and right : left ventricle volume ratio have been assessed. Results: at the gestational age of 18-21 weeks in fetuses of the control group the median of diastolic right : left ventricle volume ratio was 1.17 ml, the 5 and 95 percentile range - 1.00-1.23 ml, the minimum and maximum range - 1.00-1.23 ml; in the main group - 3.35 ml, 1.24-17.20 ml, 1.24-11.84 ml, respectively (P = 0.001). The sensitivity of diastolic right : left ventricle volume ratio > 1.23 in the in diagnosis of significant hypoplasia of the left ventricle in hypoplastic left heart syndrome - 100.0% (taking into account the inclusion to the main group the fetuses with left ventricle linear dimensions equal or below to lower limit of normal values with background of normal right ventricle dimensions). Conclusion: the use of right : left ventricle volume ratio allows to minimize 2D and 3D/4D measurement errors of absolute parameters, and reduce intraobserver and interobserver variability in ultrasound measurements.