Predição da hipoplasia pulmonar letal por meio da ultrassonografia tridimensional, em fetos de risco

Abstract

Objective: To study the ability of three-dimensional sonography in predicting lethal pulmonary hypoplasia in fetuse at risk for this outcome. Methods: From 47 fetal were performed lung bilateral scans during one ultrasound session, three times. Three samples of 3D ultrasound fetal chest volume were acquired preferably when the fetus was facingtowards the transducer and was not moving. The VOCAL method was used to obtain a sequence of six sections of each lung around a fixed axis and a rotation angle of 30o was adopted. The lung volume reprodubility was evaluated by the intraclass correlation coefficient. The lung volume measurements were analyzed according to nomogram. Afterbirth, lung hypoplasia was diagnosed considering clinical, radiologic, and pathologic criteria. Results: Thirty-four (72.3%) conceptuses had lethal lung hypoplasia. No significant intraobserver difference was observed at measurements of the right lung (ICC=0.973, p<0,0001) or left lung (ICC=0.984, p<0,0001). The overall accuracy of the 3D ultrasound lung volume for predicting this condition was better than 2D ultrasoundparameters: sensitivity=88.2%, predictive negative value=75% and positive likelihood ratio=11.5. Most of the cases with lung hypoplasia (18, 52.9%) were affected by renal and urinary tract malformations that was statistically associated to this condition (p=0.020). The 3D lung volume per estimated fetal weigh ratio was 100% predictive in detectinglethal lung hypoplasia when the result was abnormal. Conclusion: The present study suggests that the three-dimensional ultrasound has a good capacity of prediction of lethal pulmonary hypoplasia in fetuses at risk, with a good accuracy.