Two- or three-dimensional ultrasonography: which is the best predictor of pulmonary hypoplasia?

OBJECTIVE: The aim of our study is to compare the three-dimensional (3D) ultrasound fetal lung volume measurements with two-dimensional (2D) ultrasound biometric parameters in predicting pulmonary hypoplasia (PH). METHODS: From June 2006 to November 2008, we identified 35 fetuses at high risk for developing PH, including premature preterm rupture of membranes (17), fetal skeletal malformations (7), hydrothorax (7), and bilateral renal dysplasia (4). 3D lung volumes adjusted for gestational age (GA) or estimated fetal weight (EFW), thoracic circumference adjusted for GA or femur length, thoracic/abdominal circumference ratio, and thoracic/heart area ratio were measured. RESULTS: Three infants were excluded because no clinical or histological information regarding lung hypoplasia was available. Of the 32 remaining infants, 13 (41%) were diagnosed with PH at postmortem examination or by clinical and radiological examination. 3D lung volume measurements had a better diagnostic accuracy for predicting PH either when adjusted for GA [sensitivity, 12/13 (92%); specificity, 16/19 (84%); positive predictive value 12/15 (80%); negative predictive value, 16/17(94%)] or EFW [sensitivity, 11/13 (85%); specificity, 18/19 (94%); positive predictive value 11/12(92%); negative predictive value, 18/20(90%)] compared to the 2D biometric measurement. CONCLUSION: 3D lung volume measurements seem to be useful in the prenatal prediction of PH.

Interobserver reproducibility of transabdominal 3-dimensional sonography of the fetal brain.

OBJECTIVE: The purpose of this study was to assess the interobserver reproducibility of transabdominal 3-dimensional (3D) fetal neurosonography. METHODS: This was a prospective observational study. We studied 23 consecutive singleton pregnancies between 18 and 23 weeks' gestation. All cases had normal fetal neurosonographic examination findings, which were confirmed after birth. A 3D sonographic volume of the fetal head was acquired transabdominally by a single operator using an axial approach. Fetal brain anatomy was later analyzed offline by 2 different operators. Axial, sagittal, and coronal views of the fetal brain were obtained to perform a detailed evaluation of the fetal brain. Each operator defined the scanning planes obtained as adequate or inadequate. Results were evaluated with 2 x 2 tables and the Cohen kappa coefficient to assess interobserver agreement. RESULTS: Good-quality multiplanar images were obtained in 23 of 23 cases. The rate of adequate visualization was 100% for all of the axial planes, with kappa values of 1.00. For sagittal and coronal planes, the rate of visualization ranged between 78% and 91%, with kappa values ranging between 0.61 and 0.83. CONCLUSIONS: Transabdominal 3D sonography of the fetal brain at 18 to 23 weeks' gestation has an acceptable degree of interobserver reproducibility.