New anatomical landmarks to study the relationship between fetal lung area and thoracic circumference by three-dimensional ultrasonography

• Published in: The journal of maternal-fetal & neonatal medicine Vol. 25; no. 10; pp. 1927 - 1932
• Main Authors: Werneck Britto, Ingrid Schwach, Tedesco, Giselle Darahem, Herbst, Sandra Rejane Silva, Silva Bussamra, Luiz Cláudio, de Andrade, Fernando Moreira, Júnior, Edward Araujo, Nardozza, Luciano Marcondes Machado, Ruano, Rodrigo, Moron, Antonio Fernandes, Aoki, Tsutomu
• Format: Journal Article
• Language: English
• Published: England Informa Healthcare 01-10-2012; Taylor & Francis
• Subjects: Adolescent; Adult; Female; Fetal Development; Fetal lung area; fetal thoracic circumference; Fetus - anatomy & histology; Gestational Age; Humans; Imaging, Three-Dimensional; Linear Models; Longitudinal Studies; Lung - anatomy & histology; Lung - diagnostic imaging; Lung - embryology; multiplanar mode; Observer Variation; Pregnancy; Prospective Studies; reference intervals; Reference Values; Thorax - anatomy & histology; Thorax - diagnostic imaging; Thorax - embryology; three-dimensional ultrasonography; Ultrasonography, Prenatal; Young Adult
• ISSN: 1476-7058; 1476-4954
• DOI: 10.3109/14767058.2012.667176

Objective: To evaluate the relation between total lung area (TLA) and thoracic circumference (TC) ratio by three-dimensional (3D) ultrasonography applying new anatomical landmarks as the fetal aorta and inferior angle of the scapula. Methods: A longitudinal prospective study was conducted with 56 uncomplicated pregnancies between 24 and 32 weeks of gestation. Polynomial regressions were used to evaluate the correlation between TC and gestational age (GA) as well as TC and estimated fetal weight (EFW). A simple linear regression was used to evaluate the correlation between TLA and Total thoracic area (TTA) and GA. The intraclass correlation coefficient (ICC) was used to assess the intra and interobserver variability. Results: 127 examinations were performed. TC values ranged from 150 to 174 mm (mean 166 mm) at 24 weeks and 215-248 mm (mean 231 mm) at 32 weeks. The TLA/TC ratio ranged from a mean of 0.64 at 24 weeks (range 0.56-0.70) to 0.90 at 32 weeks gestation (range 0.79-1.01). The intraobserver variability using the ICC was of 0.919 for TC; 0.916 for TTA; 0.860 for right lung area (RLA) and 0.910 for left lung area (LLA). Interobserver reproducibility was with an ICC of 0.970 for TC; 0.984 for RLA and 0.910 for LLA. Conclusions: Measurement of fetal TC and the relationship between TLA and TC by 3D-ultrasonography applying new anatomical landmarks shows good reproducibility and allows a new assessment of thoracic and lung growth.