Three-dimensional ultrasonography using virtual organ computer aided analysis technique in predicting pulmonary hypoplasia of fetus

Objective: To observe the feasibility of virtual organ computer-aided analysis (VOCAL) technique in estimating the fetal lung volume, and to assess the diagnostic value of ultrasound fetal lung to body weight ratio (UFLB) in fetal pulmonary hypoplasia (PH). Methods: A total of 35 fetuses (16-36 weeks) with congenital malformation diagnosed with prenatal ultrasonography were enrolled in this study. The autopsy was permitted. The fetal lung volume was estimated with three-dimensional ultrasonography using VOCAL technique, while the fetal weight was measured with 2D ultrasonography with Hadlock equation. The lung volume obtained with VOCAL technique was compared with the actually measured volumes postnatally, and the value of UFLB in the diagnosis of fetal PH was evaluated. Results: The bias of the fetal lung volume obtained with the two methods was (-0.81±1.77)cm ³. The sensitivity, specificity, positive and negative predictive values of UFLB in diagnosing fetal PH was 83.33%, 95.65%, 90.91% and 91.67%, respectively, and the accuracy was 91.43%. Conclusion: The fetal lung volume can be estimated precisely with three-dimensional ultrasonography using VOCAL technique. UFLB may be useful in the prenatal diagnosis of fetal PH.