According to Lassandro F et al CT findings retrospectively observed were: bowel loops dilatation, air-fluid levels, biliodigestive fistula,
pneumobilia, ectopic stone and extraluminal fluid.
Ultrasonography and computed tomography (CT) are more effective than plain radiographs in revealing bile stones, ectopic gallstones,
pneumobilia, and gallbladder abnormalities (8).
The gallbladder was collapsed and
pneumobilia was seen in the biliary tract (Figure 1).
Diverse abdominal disorders can cause gas or air accumulation in the biliary tree, termed "
pneumobilia." Causes include incompetent sphincter of Oddi, biliary enteric surgical anastomosis, biliary enteric fistula, acute cholangitis, cholangiography from ERCP or PTC, gallbladder infarction, hepatic abscess, or abdominal trauma [18].
The differential diagnosis of Chilaiditi's syndrome includes pneumoperitoneum,
pneumobilia, and hepatic-portal venous gas.
Caption: Figure 2: Mesenteric venous gas and
pneumobilia.
Probably owing to low calcium content in these stones, they are rarely picked up in plain X-rays [9, 10]; on the other hand findings like
pneumobilia on the same could suggest gallstone ileus that must be supported with findings of biliary abnormalities on ultrasonography [11].
Classically the findings on abdominal radiographs are mechanical bowel obstruction,
pneumobilia, and an ectopic gallstone within bowel lumen (Rigler's triad).
10
Pneumobilia is a common finding and is due to either the reflux of enteric gas from stone passage across the ampulla or due to infection with gas-forming organisms.
In a patient with gallstone ileus, imaging studies typically show a classic radiographic triad (Rigler's triad) consisting of small bowel obstruction,
pneumobilia, and an ectopic gallstone.
The classic Riglers triad of radiography includes mechanical bowel obstruction
pneumobilia and an ectopic gallstone within bowel lumen.
A repeat ultrasound scan showed
pneumobilia with no biliary dilatation or mass.