Background: In malrotation the position of third portion of duodenum (D3) is always intramesenteric. Demonstration of normal retromesenteric-retroperitoneal position of D3 on ultrasound (US) can rule out malrotation. The aim of this study was to evaluate the feasibility of US in demonstrating the retroperitoneal D3.
Material/methods: Abdominal US study was done for various indications in 60 newborns and infants (mean age: 33 days [range: 4-100 days]; 56.7% male) by an expert pediatric radiologist. The position of D3 and its adjacent structures was evaluated in axial and longitudinal planes by linear and curved transducers.
Results: A normal retromesenteric-retroperitoneal D3 located between the superior mesenteric artery and the aorta was seen on US in all patients, including those with extensive gas in the bowel. The mean time of D3 observation was 47.8 s (10-180 s). Ultrasound was also capable of demonstrating D3 structure, diameter, content, adjacent structures, relative position of the superior mesenteric artery and vein.
Conclusions: Ultrasound is a simple, fast and highly accurate tool to confirm the retroperitoneal position of D3. Ultrasound can be used as a screening method for malrotation eliminating the need for unnecessary barium studies.
Keywords: Duodenum; Malrotation; Ultrasound.