CHAOS: Prenatal imaging findings with post mortem contrast radiographic correlation.

Congenital high airway obstruction syndrome is a rare fetal anomaly with characteristic constellation of prenatal findings on ultrasound and MRI. The typical triad of imaging features are enlarged and echogenic lungs, flattening or inversion of diaphragm and fetal hydrops. Early prenatal recognition of congenital high airway obstruction syndrome by ultrasound and/or MRI is mandatory for the appropriate perinatal management. We report a case of a male fetus with typical imaging findings of congenital high airway obstruction syndrome on ultrasound and MRI at 19 weeks of gestation. The role of contrast radiographs of fetal airways, including retrograde laryngogram, in confirming the postnatal diagnosis of this fetal condition is demonstrated. The prenatal imaging findings were correlated with contrast radiographs of upper airways, sonography of aborted fetus and fetal autopsy findings.