Study Smarter
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.
A pneumoretroperitoneum may be appreciated in each of the CT images presented above. In the left image, air is seen surrounding the right kidney, whereas the right image shows retroperitoneal air pushing the bowel centrally on the patient’s right side. [Courtesy of Dr. N. Jaffer]
Free air in the retroperitoneum makes retroperitoneal structures such as the psoas muscles and the kidneys visible. [Courtesy of Dr. N. Jaffer]
Free peritoneal air is difficult to assess in a single, supine, plain film study.
However, in the study above, one can appreciate the air visualized on both sides of the left hemidiaphragm. [Courtesy of Dr. N. Jaffer]
Air both inside and outside of the bowel wall creates contrast effect enabling the visualization of both the inner and outer limits of the bowel wall. [Courtesy of Dr. N. Jaffer]
Cupola sign refers to peritoneal air that is superior to the left lobe of the liver, having the appearance of a long, flat hat, hence the term “cupola” meaning hat. [Courtesy of Dr. N. Jaffer
