From the Guidelines
Computed tomography (CT) scan of the abdomen and pelvis with intravenous and oral contrast is the recommended imaging study for diagnosing diverticulitis. This imaging modality is preferred because it can clearly visualize the inflamed diverticula, assess the extent of inflammation, and identify potential complications such as abscesses, perforations, or fistulas. The sensitivity of CT for diagnosing diverticulitis ranges from 94-99%, making it highly reliable 1. Patients should receive oral contrast approximately 1-2 hours before the scan and intravenous contrast during the procedure unless contraindicated (such as in renal impairment or contrast allergy) 1.
Key Points to Consider
- CT scan is the most useful examination for patients with suspected complications of colonic diverticulitis due to its reproducibility, superior diagnostic accuracy, and ability to demonstrate other causes of left lower quadrant pain that mimic diverticulitis 1.
- The use of IV contrast material can improve the characterization and detection of subtle bowel wall abnormalities and complications of diverticulitis, such as diverticular abscess 1.
- While ultrasound may be used as an alternative in certain situations (pregnancy, young patients, or when CT is unavailable), it is operator-dependent and less sensitive 1.
- MRI can be considered in pregnant patients or those who cannot undergo CT 1.
- The advantage of CT is that it not only confirms the diagnosis but also helps stage the severity of diverticulitis, which directly impacts treatment decisions regarding antibiotic selection, need for hospitalization, or surgical intervention 1.
Clinical Decision Making
When diagnosing diverticulitis, it is essential to consider the patient's clinical presentation, medical history, and potential contraindications to CT scans. CT scans with intravenous and oral contrast are the preferred initial imaging modality for suspected acute diverticulitis in non-pregnant adults 1. However, in cases where CT is contraindicated or unavailable, ultrasound or MRI may be considered as alternative diagnostic modalities 1. Ultimately, the choice of imaging study should be guided by the patient's individual needs and the clinical context.
From the Research
Imaging Studies for Diverticulitis
To diagnose diverticulitis, the following imaging studies are recommended:
- Computed Tomography (CT) of the abdomen and pelvis with intravenous contrast is accepted as the best imaging method for evaluating diverticular inflammation 2, 3, 4, 5, 6
- 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
- CT-guided drainage of diverticular abscesses helps to reduce sepsis and to permit a one-stage, rather than two-stage, surgical operation 3, 4
Advantages of CT Imaging
The advantages of CT imaging in diagnosing diverticulitis include:
- High sensitivity and specificity in making a diagnosis of diverticulitis 2, 5
- Ability to evaluate the disease severity and degree 2
- Ability to diagnose complications such as abscess formation, intestinal penetration, or perforation 3, 4, 5, 6
- Guidance for therapy planning in the presence of complications 2
Comparison with Other Imaging Studies
Compared to other imaging studies, such as water-soluble contrast enema (CE), CT has been shown to be superior in terms of sensitivity and evaluation of the severity of inflammation 5. CT is also preferred over CE as the initial radiological exam of diverticulitis due to its higher performance in detecting severe infection, especially when an abscess is associated with the disease 5.