Diastematomyelia: prenatal ultrasonic appearances.

Four cases of in-utero diastematomyelia are presented and the ultrasonic features described. Characteristic findings are localised widening of the posterior ossification centres with a central echogenic focus at the point of widening, visible on coronal scanning, and absence of a posterior defect or soft tissue mass on transverse scanning. The aetiology and management of the condition is discussed. The cases illustrate that widening of the posterior ossification centres can occur in the absence of overt spina bifida and the prenatal detection of diastematomyelia will allow for early postnatal investigation and treatment.