From the Guidelines
Ultrasound (US) of the abdomen can detect diverticulitis with a sensitivity and positive predictive value of >90%, as demonstrated by meta-analyses and prospective studies 1. When it comes to detecting diverticulitis, the key criteria for diagnosis using US include:
- Short-segment colonic wall thickening (>5 mm)
- Inflamed diverticulum in the thickened area (hypoechoic and surrounded by hyperechoic fat)
- Noncompressible hyperechoic pericolic tissue According to the 2023 update of the ACR Appropriateness Criteria for left lower quadrant pain, US is a viable option for diagnosing diverticulitis, particularly in certain patient populations or situations where CT scans may not be feasible 1. However, it's essential to note that US has some limitations, including:
- Modestly lower accuracy compared to CT, especially in obese patients and those with distal sigmoid diverticulitis
- Lower specificity than CT, which may lead to alternative diagnoses being missed
- Requirement for a higher level of training for the diagnosis of diverticulitis, with an estimated minimum of 500 examinations needed for competency 1 Despite these limitations, US can be a useful initial imaging test, particularly in a point-of-care setting, as it is noninvasive and may reduce the number of CT scans performed without negatively impacting patient care 1.
From the Research
Diagnosis of Diverticulitis
- Diverticulitis can be suspected in patients with isolated left lower quadrant pain, abdominal distention or rigidity, fever, and leukocytosis 2.
- Computed tomography (CT) with intravenous contrast is the preferred imaging modality to confirm diagnosis and assess for complications of diverticulitis 2, 3.
- CT scan can help classify diverticulitis as complicated or uncomplicated, which guides management decisions 3, 4.
Imaging Modalities
- CT of the abdomen and pelvis with intravenous contrast is accepted as the best imaging method for evaluating diverticular inflammation 3.
- Non-contrast CT is non-inferior to contrast-enhanced CT for the diagnosis of acute colonic diverticulitis, but contrast-enhanced CT is associated with higher sensitivities for perforation and abscess 5.
- CT scan can help identify diverticula in the pathological intestinal loop, which is essential for differentiating diverticulitis from other inflammatory diseases that involve the colon 3.
Treatment and Management
- Treatment decisions for diverticulitis are based on the categorization of disease as complicated vs. uncomplicated 2, 4.
- Outpatient treatment is recommended for afebrile, clinically stable patients with uncomplicated diverticulitis, while complicated diverticulitis requires hospitalization and more aggressive treatment 4.
- Antibiotics have no proven benefit in reducing the duration of the disease or preventing recurrence in patients with uncomplicated diverticulitis, and should only be used selectively 4, 6.