Imaging description

In an otherwise healthy infant with bilious emesis, intestinal malrotation with midgut volvulus is the primary concern. An upper gastrointestinal (GI) series is the reference standard examination to evaluate for intestinal malrotation [1–3]. Barium may be used unless the patient is unstable and bowel ischemia or perforation is suspected, in which case water-soluble contrast is preferred [1]. If the infant cannot tolerate oral contrast, a nasogastric or nasoduodenal tube may be used to rapidly and safely deliver the contrast.

Ascertaining the position of the duodenal-jejunal junction (DJJ) is the primary goal of this evaluation. On a true supine AP projection, the normal DJJ is situated to the left side of the left vertebral pedicle, at or above the level of the pylorus (Figure 92.1) [1–3]. On a lateral view, the normal duodenum passes through the retroperitoneum, affording another opportunity to evaluate for proper rotation [4]. Generally if these criteria are not met then malrotation is suspected. Cecal position may then be assessed through either a delayed radiograph or contrast enema. An abnormally positioned cecum further supports malrotation. The shorter the distance between the DJJ and cecal apex, the shorter the mesenteric vascular pedicle, which then increases the risk for midgut volvulus [3].