From the Guidelines
The best imaging modality for diverticulitis is Computed Tomography (CT).
Key Points
- CT has high sensitivity and specificity for diagnosing diverticulitis, with reported sensitivities of 92-99% and specificities of 97-100% 1.
- CT is the preferred imaging modality for patients with suspected diverticulitis, as it allows for diagnosis of other causes of left lower-quadrant pain and can guide percutaneous drainage when abscesses are present 2.
- CT can predict unfavorable outcomes from acute diverticulitis, such as longer hospitalization and need for surgery, and can differentiate between contained extraluminal air and abscess from spilled feces 3.
- The American College of Physicians suggests using abdominal CT imaging when there is diagnostic uncertainty in a patient with suspected acute left-sided colonic diverticulitis, with moderate-certainty evidence showing high sensitivity and specificity for CT imaging 4.
- The use of CT-scan with IV-contrast is recommended in all elderly patients with suspected diverticulitis to confirm the diagnosis and distinguish complicated from non-complicated diverticulitis, with alternative diagnostic approaches such as US, MRI, or CT-scan without IV-contrast available for patients who cannot undergo CT-scan with IV-contrast 5.
Important Considerations
- CT imaging should be used judiciously in female patients of childbearing age in whom gynecologic etiologies have been clinically or sonographically excluded.
- Abdominal ultrasonography can be considered when CT cannot be obtained, and abdominal magnetic resonance imaging can be considered when ultrasonography provides inconclusive results.
- Clinicians should err on the side of imaging in patients with predictors of progression to complicated diverticulitis, such as symptom duration longer than 5 days and signs of perforation, bleeding, obstruction, or abscess.
From the Research
Imaging Modalities for Diverticulitis
The best imaging modality for diverticulitis is a topic of discussion among medical professionals. According to various studies, the following points can be considered:
- Computed Tomography (CT) is a highly sensitive and specific modality for the diagnosis of acute diverticulitis and its complications, as well as for the exclusion of alternate causes of pathology 6, 7, 8, 9, 10.
- CT is superior to ultrasound (US) in detecting free air, fecal peritonitis, and deeply located abscesses, especially in obese patients 6.
- US may be superior to CT in not too obese patients, and is most useful in early, uncomplicated diverticulitis 6.
- US can be used as a first modality in acute abdomen, and daily repeated US examinations can help monitor the progression of diverticulitis 6.
- Magnetic Resonance Imaging (MRI) and virtual CT colonoscopy have important adjunct roles for screening and workup of complications in specific patient populations 7.
Advantages of CT Scans
CT scans have several advantages in diagnosing diverticulitis, including:
- Ability to demonstrate intra- and/or extramural inflammation 9.
- Capability to identify extracolonic extent of disease 10.
- Useful in assessing mild or severe acute diverticulitis, providing information for appropriate treatment planning in the emergency setting 9.
- Can detect complications such as sigmoid mesentery abscess, fistula, and peritonitis 9.
Limitations of Other Imaging Modalities
Other imaging modalities, such as US and barium enema, have limitations in diagnosing diverticulitis: