What is the primary reason for performing an X-ray in the case of suspected midgut malrotation?

The primary reason for performing an X-ray in cases of suspected midgut malrotation is to rule out pneumoperitoneum. Pneumoperitoneum refers to the presence of air in the peritoneal cavity, which can indicate perforation of the gastrointestinal tract. In the context of midgut malrotation, there is a risk of volvulus (twisting of the intestine), which can lead to ischemia and, ultimately, perforation. Detecting free air in the abdominal cavity via X-ray is critical for assessing complications arising from midgut malrotation, as this finding would necessitate urgent surgical intervention.

While the other options also describe important aspects of diagnosing conditions related to midgut malrotation, ruling out pneumoperitoneum provides immediate and crucial information regarding the potential severity of the situation, guiding further management and interventions.