腹部 中肠扭转 "apple-peel / twisted ribbon / corkscrew" appearance

· Torsion of entire gut around superior mesenteric artery (SMA) due to a short mesenteric attachment of small intestine in malrotation

· Age
o Usually neonate or young infant
o Occasionally older child and adult

· Associated with (in 20%)
o Duodenal atresia
o Duodenal diaphragm
o Duodenal stenosis
o Annular pancreas

· Pathophysiology:
o Degree of twisting is variable and determines symptomatology
o Severe volvulus (= twist of 3 1/2 turns)
§ Can result in bowel necrosis

· Acute symptoms in newborn (medical emergency)
o Bile-stained vomiting
§ Intermittent
§ Postprandial
§ Projectile
o Abdominal distension
o Shock

· Intermittent obstructive symptoms in older child
o Recurring attacks of nausea
o Vomiting
o Abdominal pain
o Failure to thrive (hypoproteinemic gastroenteropathy as a result of lymphatic and venous obstruction)

· Plain film findings
o Dilated, air-filled duodenal bulb and paucity of gas distally
§ "Double bubble sign" = air-fluid levels in stomach and duodenum
o Isolated collection of gas-containing bowel loops distal to obstructed duodenum = gas-filled volvulus = closed-loop obstruction
§ From nonresorption of intestinal gas secondary to obstruction of mesenteric veins

· Barium studies
o Duodenojejunal junction (ligament of Treitz) located lower than duodenal bulb and to the right of expected position
o Spiral course of midgut loops = "apple-peel / twisted ribbon / corkscrew" appearance (in 81%)

http://radiology.rsnajnls.org/cgi/reprint/242/1/315