From the Guidelines
CT scans for diverticulitis should be performed with intravenous (IV) contrast to provide optimal visualization of the inflamed bowel wall and potential complications. The use of IV contrast material is commonly used to improve the characterization and detection of subtle bowel wall abnormalities and complications of diverticulitis, such as abscesses 1. However, in emergency situations where rapid diagnosis is needed, CT can be performed without oral contrast, and non-contrast CT may be considered for patients with contraindications to IV contrast, such as severe renal impairment or contrast allergy, though this reduces diagnostic accuracy 1. Some key points to consider when using CT scans for diverticulitis include:
- The preferred imaging approach is a contrast-enhanced CT scan of the abdomen and pelvis, which provides superior diagnostic accuracy and can help identify complications such as abscesses or fistulas 1.
- Oral contrast may also be administered to help distinguish the bowel lumen from surrounding structures, but it is not always necessary 1.
- Unenhanced CT can be used in patients with contraindications to IV contrast material, but it is less accurate than contrast-enhanced CT 1.
- Radiation dose-reduced contrast-enhanced CT can be accurate for acute diverticulitis, with a similar sensitivity and specificity to standard dose contrast-enhanced CT 1. The enhanced visualization provided by contrast allows clinicians to better assess disease severity, identify complications, and guide appropriate treatment decisions, whether conservative management with antibiotics or surgical intervention is needed 1.
From the Research
CT Scan for Diverticulitis
- The use of computed tomography (CT) scans is a common practice for diagnosing diverticulitis, as it provides radiological evidence of inflammation 2.
- CT scans are particularly useful in determining the severity of diverticulitis and identifying complications such as perforation or abscesses 2, 3.
Use of Contrast in CT Scans
- A study published in 2024 compared non-contrast CT scans with contrast-enhanced CT scans for the diagnosis of acute colonic diverticulitis, and found that non-contrast CT scans were non-inferior to contrast-enhanced CT scans 4.
- However, the study also noted that contrast-enhanced CT scans had higher sensitivities for detecting abscesses or perforation 4.
- Another study published in 1990 highlighted the limitations of CT scans in diagnosing acute diverticulitis, including the inability to visualize small amounts of fibropurulent exudate and failure to detect discrete intramural abscesses 5.
Guidelines for CT Scan Use
- The management of diverticulitis guidelines recommend the use of CT scans to diagnose and classify diverticulitis as complicated or uncomplicated 2.
- Patients with uncomplicated diverticulitis may not require contrast-enhanced CT scans, while patients with complicated diverticulitis or suspected abscesses or perforation may benefit from contrast-enhanced CT scans 4, 3.
- Colonoscopy is recommended for patients with complicated diverticulitis or those who have suspicious features on CT scans, as it can help exclude underlying malignancy 2, 6.