Fetal lung volume in fetuses with urinary tract malformations: Comparison by 2D-, 3D-sonography and magnetic resonance imaging

Abstract

Objective. To evaluate the concordance between two-dimensional ultrasonography (2DUS), three-dimensional ultrasonography (3DUS) and magnetic resonance imaging (MRI) in the assessment of lung volume in fetuses with urinary tract malformations (UTM).

Methods. This was a cross-sectional study involving 12 pregnancies between 19 and 34 weeks, with various fetal UTM. Pulmonary volume was obtained by 2DUS using the following equation: total lung volume = [right lung antero-posterior diameter (X) × transverse diameter (Y) × cranial-caudal diameter × 0.152 + left lung (X1) × (Y1) × (Z1) × 0.167]. Pulmonary volume by 3DUS was obtained using the virtual organ computer-aided analysis (VOCAL) method with a 30° (VOL30), 18° (VOL18) and 12° (VOL12) rotation. A fast sequence of transverse lung section was also obtained by MRI. The intraclass correlation coefficient was used to evaluate the correlation between the three methods. The paired student t-test was used to compare the means.

Results. There was a strong correlation between the three methods, and the highest correlations were between MRI and VOL18 for the right (ICC = 0.913) and left (ICC = 0.947) lungs. A strong correlation was also found between the lung volumes obtained through MRI and VOL12 as well as VOL18 (p = 0.544 and 0.286, respectively). However, for the left lung there was only a correlation between MRI and VOL12 (p = 0.49).

Conclusions. There is a good concordance between 3DUS (VOL12) and MRI in the evaluation of lung volume in fetuses with UTM.

Keywords:

• Fetal lung volume
• two-dimensional ultrasonography
• three-dimensional ultrasonography
• magnetic resonance imaging

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.