Assessment of fetal lung volumes and liver herniation with magnetic resonance imaging in congenital diaphragmatic hernia.

OBJECTIVE: We evaluated the use of fetal magnetic resonance imaging in predicting outcomes after ultrasonographic diagnosis of left-sided congenital diaphragmatic hernia. STUDY DESIGN: Forty-one pregnant women carrying fetuses with congenital diaphragmatic hernia underwent 43 magnetic resonance imaging scans. Lung volumes were calculated by summing the areas on 6-mm axial sections. The presence or absence of liver herniation was noted. A liver/diaphragm ratio was obtained by using the distances from the superior aspect of the liver and the diaphragmatic remnant to the apex of the chest. RESULTS: Mean gestational age was 26 weeks and overall survival was 59%. Neither right, left, nor total lung volume measurements were predictive of survival. Liver herniation into the left side of the chest was predictive of outcome at P<.05. The liver/diaphragm ratio was predictive of outcome at P = .03. CONCLUSION: Fetal magnetic resonance imaging permits calculation of lung volumes, but these volumes are not predictive of outcome. However, both the presence of liver herniation and the volume of liver within the chest, as reflected by the liver/diaphragm ratio, help predict outcome in left-sided congenital diaphragmatic hernia.

MRI for the assessment of the malformed fetus.

Ultrafast MRI sequences have changed the use of MRI for evaluating fetal abnormalities. Currently, the best application is the demonstration of normal fetal brain development and the further definition of suspected brain abnormalities found on ultrasound. MRI differentiates well the various types of fetal ventriculomegaly. Superior posterior fossa visualization allows differentiation of Dandy Walker malformation from a large cisterna magna. Anomalies of the corpus callosum and some disorders of neuronal migration can be seen. MRI is also valuable in the evaluation of fetal giant neck masses for planning delivery of the baby and surgery for life threatening airway obstruction. In the chest, MRI differentiates masses such as diaphragmatic hernia, cystic adenomatoid malformation and sequestration, and aids in planning fetal surgery because MRI directly visualizes the position of the lung, liver and bowel. MRI defines abnormalities of the urinary tract by demonstrating dysplastic pathology in the renal cortex and dilation of the collecting systems. Oligohydramnios does not effect MRI.