From the Guidelines
The preferred scan for diagnosing diverticulitis is a CT scan of the abdomen and pelvis, as it provides the most accurate diagnosis and assessment of severity, with a diagnostic accuracy of 98% 1. This imaging technique is useful for patients with suspected colonic diverticulitis because of its reproducibility, superior diagnostic accuracy, and ability to demonstrate other causes of left lower quadrant pain that mimic diverticulitis. Some key points to consider when using CT scans for diverticulitis include:
- IV contrast material is commonly used to improve the characterization and detection of subtle bowel wall abnormalities and complications of diverticulitis, but it is not necessary for the diagnosis of diverticulitis in most patients 1.
- Unenhanced CT can be used in patients with contraindication to IV contrast material and is more accurate than clinical evaluation alone 1.
- Radiation dose–reduced CT can be accurate for acute diverticulitis, with a similar sensitivity and specificity to standard-dose CT 1. For patients who cannot undergo CT scanning due to pregnancy or other contraindications, alternatives include ultrasound or MRI, but CT is the most accurate and widely used modality for confirming the diagnosis of diverticulitis and assessing its severity 1. The choice of imaging should be guided by the clinical presentation, with CT being the preferred modality for most cases. It's worth noting that the use of CT scans can help predict which patients are likely to experience recurrent diverticulitis and thereby augment triage between surveillance and operative management 1.
From the Research
Imaging Modalities for Diverticulitis
- Computed Tomography (CT) is widely accepted as the best imaging method for evaluating diverticular inflammation 2, 3, 4, 5
- CT scan is useful in confirming the presence of acute colonic diverticulitis (ACD), evaluating the disease severity and degree, and guiding therapy planning in presence of complications 2
- CT scan can also help differentiate diverticulitis from other diseases that may cause abdominal pain, such as neoplasm, inflammatory bowel disease, and colon ischemia 2
Comparison of Imaging Modalities
- CT scan has been compared to other imaging modalities such as barium enema, ultrasound, and magnetic resonance imaging (MRI) 4, 6, 5
- Studies have shown that CT scan is more sensitive and accurate than barium enema in diagnosing diverticulitis, especially in patients with severe disease 6, 5
- CT scan is also better than contrast enema in evaluating the severity of inflammation and detecting associated complications such as abscesses 5
Recommendations for Imaging
- CT scan is recommended as the initial radiologic examination for suspected diverticulitis due to its high sensitivity and ability to detect complications 4, 5
- Barium enema and other imaging modalities may be used in certain situations, such as when CT scan is not available or in patients who are unable to undergo CT scan 6