What does magnetic resonance imaging add to the prenatal ultrasound diagnosis of facial clefts?

OBJECTIVE: Ultrasound is the modality of choice for prenatal detection of cleft lip and palate. Because its accuracy in detecting facial clefts, especially isolated clefts of the secondary palate, can be limited, magnetic resonance imaging (MRI) is used as an additional method for assessing the fetus. The aim of this study was to investigate the role of fetal MRI in the prenatal diagnosis of facial clefts. METHODS: Thirty-four pregnant women with a mean gestational age of 26 (range, 19-34) weeks underwent in utero MRI, after ultrasound examination had identified either a facial cleft (n = 29) or another suspected malformation (micrognathia (n = 1), cardiac defect (n = 1), brain anomaly (n = 2) or diaphragmatic hernia (n = 1)). The facial cleft was classified postnatally and the diagnoses were compared with the previous ultrasound findings. RESULTS: There were 11 (32.4%) cases with cleft of the primary palate alone, 20 (58.8%) clefts of the primary and secondary palate and three (8.8%) isolated clefts of the secondary palate. In all cases the primary and secondary palate were visualized successfully with MRI. Ultrasound imaging could not detect five (14.7%) facial clefts and misclassified 15 (44.1%) facial clefts. The MRI classification correlated with the postnatal/postmortem diagnosis. CONCLUSIONS: In our hands MRI allows detailed prenatal evaluation of the primary and secondary palate. By demonstrating involvement of the palate, MRI provides better detection and classification of facial clefts than does ultrasound alone.