Gastrointestinal radiography

Malrotation and intestinal volvulus

In symptomatic newborns, the pathology manifests with bilious vomiting. Plain radiography has limitations: the finding may be normal (with mild torsion), mimic the «double bubble» sign (in partial duodenal obstruction), or indicate necrosis («gasless» abdomen, closed-loop pattern).

To confirm the diagnosis in patients without overt peritonitis, an upper gastrointestinal contrast study is performed. The main objective is to determine the position of the duodenojejunal flexure (duodenojejunal flexure, DJF). Normally, it is located at the level of the duodenal bulb to the left of the vertebral pedicle roots. In malrotation, the flexure is displaced inferiorly and to the right.

Pathognomonic radiographic signs of midgut volvulus:

• «Corkscrew» sign (corkscrew pattern): spiral course of the duodenum and jejunum around the mesenteric vessels.
• «Abrupt cut-off» sign (abrupt cut-off): sudden cessation of contrast in the third part of the duodenum.

Neuromuscular disorders and pseudo-obstruction

The clinical presentation of progressive systemic sclerosis (scleroderma) and visceral myopathies is characterized by recurrent intestinal obstruction in the physical absence of a mechanical barrier (pseudo-obstruction).

Barium radiographs in scleroderma visualize:

• Dilatation of the duodenum and jejunum, delayed transit.
• Increased number of mucosal folds (valvulae conniventes), producing the «wire spring» (wire spring) or «hidebound appearance» (hidebound appearance) phenomenon.
• Sacculations: large pseudodiverticula with a wide base and a «square» contour. Their absence helps differentiate visceral myopathy from scleroderma.

The most severe form in children is megacystis-microcolon-intestinal hypoperistalsis syndrome (typically fatal in the first year of life). In such patients, a contrast enema helps rule out true mechanical obstruction.

Hydrostatic reduction of intussusception

In intussusception, fluoroscopy allows not only the visualization of the intussusceptum head as a filling defect, but also therapeutic hydrostatic reduction.

The complexity of the procedure increases as the intussusceptum advances from the transverse colon into the ascending colon and cecum. Overcoming the edematous ileocecal valve is considered the most difficult part. A reliable radiographic criterion for the complete and successful reduction of intussusception is adequate contrast filling of the terminal ileum and proximal small bowel loops.

Ultrasound as a substitute for X-ray: pyloric stenosis and vasculitis

Although GI pathologies in infants were previously evaluated fluoroscopically, ultrasound is now the imaging modality of choice for many conditions:

1. Hypertrophic pyloric stenosis (Hypertrophic Pyloric Stenosis). Boys are more frequently affected; having a first-degree relative with this diagnosis increases the risk 5-fold. Ultrasound reveals an elongated pyloric channel measuring greater than 17 mm (up to 15 mm is normal) and a thickened hypoechoic muscle with a hyperechoic mucosa. Abnormally vigorous peristaltic waves are characteristic.
2. Henoch-Schönlein purpura (Henoch-Schönlein Purpura). In this systemic vasculitis, children develop edema and hemorrhage of the bowel wall (risk of intussusception). Ultrasound demonstrates focal wall thickening and decreased peristalsis against the background of a normal or dilated caliber of adjacent loops.

Class and exam questions

What else to study on this topic

• Imaging appearance of Meckel's diverticulitis on ultrasound and contrast-enhanced CT.
• Eosinophilic gastroenteritis: association with food allergens and atopy.
• MRI features of mesenteric lymphangioma (contrast enhancement in the septa).
• Fluoroscopy of a sliding hiatal hernia.
• Syndromes associated with malrotation (Hirschsprung's disease, prune belly syndrome).

Other Topics in "Pediatric Diagnostic Radiology"

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