Neonatal ultrasonography to distinguish between meconium ileus and ileal atresia.

Meconium ileus can be difficult to distinguish from ileal atresia on plain radiographs and on contrast enema. Both show a microcolon in the face of a small bowel obstruction. The treatment of the two is very different. Meconium ileus obstruction may be relieved medically by contrast enema; ileal atresia requires prompt surgical intervention. This study was made to determine if abdominal ultrasonography might be helpful in distinguishing between these two entities. Abdominal ultrasonograms from the past 10 years of all patients with these two diseases who were studied with preoperative ultrasonography at Arkansas Children's Hospital were reviewed. Six of 16 patients with meconium ileus had preoperative ultrasonograms. All six patients with meconium ileus had multiple loops of bowel filled with very echogenic thick meconium. Four of 22 patients with ileal atresia had preoperative ultrasonograms. These four patients with ileal atresia had dilated loops of bowel filled with fluid and air. None had a dilated bowel filled with thick echogenic contents. Preoperative abdominal ultrasonography is proposed as a simple method for distinguishing between these two disease entities with very different treatment plans.