with administration of intravenous contrast media,
is the most accurate imaging modality in the diagnosis of small bowel diverticula and its complications.
Small bowel diverticula are often discovered incidentally,
performing radiological examination for other reasons.
They appear as saclike mucosal herniations,
filled with air and/or fluid,
emerging on the mesenteric border of the intestine.
Small bowel diverticulitis usually can be identified on CT images by the presence of: (Fig. 1)
- focal thickening of bowel wall adjacent to the inflamed diverticula
- preserved mural stratification
- increased vascularization with engorgement of vessels
- presence of fat stranding and fluid in the surrounding mesentery
- reactive lymph nodes
Diverticulitis can have different presentations and CT scan is a useful tool for the detection of complications associated with diverticulitis such as small bowel obstruction,
abscess formation and bleeding.
Diverticulitis can determine intestinal obstruction and torsion. CT images show abnormal dilation of the bowel loops,
with or without signs of vascular compromise.
Multiplanar reconstructions are helpful to identify the presence of an inflamed diverticula adjacent to the site of the stop,
with collapsed distal bowel loop,
guiding a correct surgical approach (Fig. 2)
Perforation of a diverticulum can be suspected by the presence of free air.
Sometimes perforations can be covered by reactive inflammatory tissue; in those cases it is important to identify an inhomogeneous area,
with air bubbles on the antideclive aspect,
surrounded by hyper attenuating tissue due to the reactive response of the mesenteric fat (Fig. 3)
If an abscess is present,
CT findings may include the presence of a mass,
with smooth margins,
air-fluid level and areas of low attenuation within,
with rim enhancement after administration of contrast media and edema of the surrounding fat.
Those characteristics lack of specificity as they can be present in other conditions.
To differentiate between abscess and neoplasms the best diagnostic clue is the presence of gas and a air-fluid level within the mass.
The major complication of Meckel’s diverticulitis is hemorrhage,
due to the presence of ulcer from ectopic gastric mucosa.
On CT images nodular enhancing areas inside the diverticulum can be detected.
The second most common complication is intestinal obstruction due to torsion or intussusception of the diverticulum.
The diverticulum itself may act as a fulcrum for twisting of the small bowel with consequent obstruction (Fig. 4).
Sometimes Meckel’s diverticulitis can have an atypical presentation.
A gallstone or a enterolith can be trapped inside the diverticulum,
because of its large dimensions,
causing inflammation and obstruction and mimicking a biliary ileus (Fig. 5).