title: Correlation between US and MRI for prenatal lung volumetry in diaphragmatic hernia, and use of Doppler to identify the ipsilateral lung cap.
abstract: BACKGROUND
  Pulmonary hypoplasia is a common cause of neonatal death.
  
  
  OBJECTIVE
  To describe the correlation between relative fetal lung volume (RFLV) and lung-to-head ratio (LHR) in fetuses with unilateral diaphragmatic hernia. Additionally, to describe identification of the ipsilateral lung cap by power Doppler.
  
  
  METHODS
  Single-institution study of consecutive fetuses with diaphragmatic hernia. LHR (by US) and RFLV (by MRI) were correlated in fetuses with and without an ipsilateral lung cap seen at MRI. In four, color/power Doppler was used to follow the pulmonary artery of the ipsilateral lung to identify the compressed cap.
  
  
  RESULTS
  The study included 48 fetuses of 20-38 weeks' gestational age (mean, 26 weeks). Mean LHR was 1.52 (range, 0.6-3) in fetuses with a lung cap and 1.15 (range, 0.6-2.58) in fetuses without (P = 0.043). Mean RFLV was 47.4% (range, 18-80%) in fetuses with and 32.9% (range, 14-57%) in fetuses without a lung cap (P = 0.005). RFLV and LHR correlated (r = 0.41, P = 0.01 in those with a cap; r = 0.50, P = 0.05 in those without). Power Doppler identified the ipsilateral lung cap and pulsed Doppler confirmed pulmonary vascularization in four of four fetuses.
  
  
  CONCLUSIONS
  LHR underestimates lung volume in fetuses with an ipsilateral lung cap. Power Doppler may be useful for identifying the cap.
authors.affiliation: Department of Pediatric Radiology, University Children's Hospital Vall d'Hebron, Ps. Vall d'Hebron 119-129, 08035 Barcelona, Spain. ampcastellote@vhebron.net
authors.forename: Amparo
authors.initials: A
authors.lastname: Castellote
authors.forename: Sandra
authors.initials: S
authors.lastname: Mencho
authors.forename: Elena
authors.initials: E
authors.lastname: Carreras
authors.forename: Teresa
authors.initials: T
authors.lastname: Higueras
authors.forename: Lina
authors.initials: L
authors.lastname: Cadavid
authors.forename: Joaquim
authors.initials: J
authors.lastname: Piqueras
authors.forename: Goya
authors.initials: G
authors.lastname: Enriquez
mesh_terms: D005260:Female; D006548:Hernia, Diaphragmatic / Q000175:diagnosis*; D065630:Hernias, Diaphragmatic, Congenital; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008168:Lung / Q000000981:diagnostic imaging / Q000196:embryology / Q000473:pathology; D008176:Lung Volume Measurements / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009929:Organ Size; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016216:Ultrasonography, Prenatal / Q000379:methods*