From the Guidelines
The most appropriate next step to confirm the diagnosis in this case is A. CT scan of the abdomen. This 60-year-old man with known diverticulosis presenting with fever, nausea, and left lower quadrant pain likely has acute diverticulitis. CT scanning is the imaging modality of choice for suspected diverticulitis as it can visualize inflamed diverticula, bowel wall thickening, fat stranding, and potential complications such as abscess formation or perforation with high sensitivity and specificity, as supported by the American College of Radiology Appropriateness Criteria 1. The advantages of CT scanning in this scenario include:
- High diagnostic accuracy for diverticulitis and its complications
- Ability to identify alternative diagnoses with similar presentations
- Guidance for risk-stratification and treatment planning, including the decision for operative versus nonoperative treatment and inpatient versus outpatient triage 1
- Non-invasiveness and wide availability
Other imaging options are less suitable for initial evaluation:
- Plain radiography lacks sensitivity for diverticular disease
- Ultrasound is often limited by bowel gas and operator dependence
- MRI is unnecessarily complex and costly for initial evaluation
- Exploratory laparoscopy is overly invasive for initial diagnosis
According to the American College of Radiology Appropriateness Criteria, CT is the most useful examination for patients with suspected complications of colonic diverticulitis due to its reproducibility, superior diagnostic accuracy, and ability to guide treatment decisions 1. Therefore, a CT scan of the abdomen is the most appropriate next step to confirm the diagnosis and guide treatment in this patient.
From the Research
Diagnostic Approach
To confirm the diagnosis of diverticulitis in a 60-year-old man with a history of diverticulosis, the most appropriate next step is:
- A CT scan of the abdomen, as it is widely accepted as the best imaging method for evaluating diverticular inflammation 2, 3, 4.
Rationale
The use of CT scans in diagnosing diverticulitis is supported by several studies, which highlight its ability to:
- Confirm the presence of diverticulitis 3
- Evaluate the severity and extent of the disease 2, 3
- Guide therapy planning in the presence of complications such as abscess or intestinal perforation 2, 3
- Differentiate diverticulitis from other diseases that may cause abdominal pain 3
Comparison with Other Imaging Modalities
Other imaging modalities, such as:
- Ultrasonography, may be useful but to a lesser extent 5
- Plain radiography, is less helpful but mandatory in cases of acute abdomen 5
- MRI, has been studied in patients with complicated diverticulitis, but its use is not as widespread as CT scans 6
- Exploratory laparoscopy, is not typically used as a diagnostic tool for diverticulitis 2, 3, 4