What is the best imaging study to evaluate for diverticulosis or bowel obstruction?

From the Guidelines

The best imaging study to evaluate for diverticulosis or bowel obstruction is a CT scan of the abdomen and pelvis with intravenous and oral contrast. This recommendation is based on the most recent and highest quality study available, which emphasizes the superiority of CT scans in diagnosing and managing diverticulitis and bowel obstruction 1. CT scans provide detailed cross-sectional images of the bowel, allowing for excellent visualization of the intestinal walls, surrounding structures, and potential complications. For diverticulosis, CT can identify the presence of diverticula (outpouchings of the colon wall), inflammation, and complications such as abscess formation or perforation. In cases of bowel obstruction, CT can determine the location, cause, and severity of the obstruction, showing dilated bowel loops proximal to the obstruction and collapsed segments distally.

Some key points to consider when using CT scans for this purpose include:

• The use of intravenous contrast material can improve the characterization and detection of subtle bowel wall abnormalities and complications of diverticulitis 1
• Oral contrast material may not be necessary in all cases, but can be useful in certain situations, such as when evaluating for bowel obstruction 1
• CT scans can also help predict which patients are likely to experience recurrent diverticulitis and guide management decisions 1
• In patients with renal impairment, the protocol may be modified to use only oral contrast or non-contrast CT, though this may somewhat reduce diagnostic sensitivity 1

Overall, the evidence suggests that CT scans are the most effective imaging modality for evaluating diverticulosis and bowel obstruction, and should be used as the first-line imaging test in these cases 1.

From the Research

Imaging Studies for Diverticulosis or Bowel Obstruction

• The best imaging study to evaluate for diverticulosis or bowel obstruction is computed tomography (CT) of the abdomen and pelvis with intravenous contrast, as it is accepted as the best imaging method for evaluating diverticular inflammation 2.
• CT is useful in differentiating other diseases that may cause abdominal pain, such as neoplasm, inflammatory bowel disease, appendix inflammations, epiploic appendix inflammation, and colon ischemia 2.
• A study comparing CT and water-soluble contrast enema found that CT had significantly superior sensitivity (98% vs 92%) and better performance in evaluating the severity of inflammation 3.

Comparison with Other Imaging Modalities

• Magnetic resonance imaging (MRI)-based colonography is a new minimally invasive imaging modality that can assess diverticulosis or diverticulitis, but its feasibility and accuracy are still being evaluated 4.
• A study found that MRI colonography revealed the same diagnosis as CT in all patients without ionizing radiation, and 3D-rendered models and virtual colonoscopy can be performed 4.

Predictive Factors for Complicated Diverticulitis

• CT imaging predictors for a complicated disease course of initially uncomplicated acute diverticulitis include fluid collections and a longer inflamed colon segment 5.
• Pericolic extraluminal air is not a predictive factor for complicated diverticulitis 5.

Value of CT in Diagnosing Acute Diverticulitis

• CT is the method of choice for imaging in suspected acute diverticulitis due to its high impact on the choice of therapy and management of complications 6.
• CT imaging can diagnose acute diverticulitis complicated by abscess formation, intestinal penetration, or perforation, and has a sensitivity and specificity of up to 100% 6.