Surveillance of fetal lung lesions using the congenital pulmonary airway malformation volume ratio: natural history and outcomes

Abstract

ObjectivesThe congenital pulmonary airway malformation volume ratio (CVR) is a widely used sonographic measure of relative mass size in fetuses with lung malformations. The purposes of this study were to examine serial CVR measurements to understand longitudinal growth patterns and to determine correlation with postnatal imaging.MethodsAn institutional review boardâ approved retrospective review was performed on fetuses referred for an echogenic lung malformation between 2002 and 2014. For each fetus, the CVR was prospectively calculated using 2D ultrasound and followed with advancing gestation.ResultsBased on 40 fetuses, the mean initial CVR was 0.51â ±â 0.07 at 20.5â ±â 0.3â weeks of gestation. The CVR increased after 24â weeks of gestation (pâ =â 0.0014), peaking at a CVR of 0.96â ±â 0.11 at 25.5â ±â 0.05â weeks, followed by a significant decrease in the CVR to 0.43â ±â 0.07 prior to term (pâ <â 0.0001). However, approximately one third showed no appreciable increase in size. The mean CVR was significantly correlated with postnatal chest computed tomography (CT) size dimensions (pâ =â 0.0032) and likelihood for lung resection (pâ =â 0.0055).ConclusionsFetal lung malformations tend to follow one of two distinct growth patterns, characterized by either (1) a maximal CVR between 25 and 26â weeks of gestation or (2) minimal change in relative growth. The mean CVR correlates with postnatal CT size and operative management. © 2015 John Wiley & Sons, Ltd.What’s already known about the topic?The congenital pulmonary airway malformation volume ratio (CVR) is a common prenatal ultrasound measure of relative mass size in fetuses with lung malformations.The initial CVR and maximum CVR have been shown to be predictive of hydrops and neonatal respiratory compromise, respectively.What does this study add?Gestational age is important when interpreting CVR measurements because two thirds of lesions increase in size at 25â 26â weeks before spontaneous involution occurs.The mean CVR correlates with size measured by postnatal computed tomography scan.