Small Bowel

“U-loop sign” indicative of small bowel volvulus. [Courtesy of Dr. N. Jaffer]

Volvulus – Midgut, barium swallow

Midgut volvulus is a result of a rotational anomaly of the gastrointestinal tract. The small bowel mesentery has twisted at the root with a vascular twirl of the SMA/SMV. This then sets up a potential for vascular compromise. [Courtesy of Dr. N. Jaffer]

Small Bowel Obstruction – String of Pearls (AXR & CT)
The “string of pearls” sign in the images above is caused by air trapped at corners of valvulae conniventes. This is almost always seen in obstructed fluid filled loops of small bowel.

Upright abdominal radiograph showing dilated loops of small bowel (>3 cm; left) and differential air-fluid levels (within the same loop; right). [Courtesy of Dr. N. Jaffer]

Enteroclysis – Study of the jejunum
The jejunum has a feathery appearance due to the numerous folds, valvulae conniventes (plicae semi-circulares). [Courtesy of Dr. N. Jaffer]

Crohn’s Disease – Disappearing string sign

Terminal ileal disease is a common finding in Crohn’s Disease. Please take notice of the thin luminal bowel enhancement proximal to the cecum on the left image. On the right image, an abrupt cutoff can be appreciated (at lower centre of image) with fine “string-like” enhancement connecting the adjoining normal bowel. This is the string-sign associated with Crohn’s Disease and bowel spasm. [Courtesy of Dr. N. Jaffer]

Terminal ileitis and narrowing of the lumen due to mucosal thickening and rigidity of the bowel wall.