From the Guidelines
The most appropriate next step in diagnosing a 62-year-old man with abdominal pain, fever, and leukocytosis is to obtain abdominal imaging, preferably a CT scan of the abdomen and pelvis with intravenous contrast. This combination of symptoms strongly suggests an intra-abdominal infection or inflammation, such as diverticulitis, appendicitis, cholecystitis, or an intra-abdominal abscess. According to the study by Weinstein et al 1, imaging may not be required in certain patients with typical symptoms of diverticulitis, but there has been a trend toward greater use of imaging to confirm the diagnosis, evaluate the extent of disease, and detect complications.
Before the CT scan, basic laboratory tests should be completed, including a complete blood count to confirm and quantify the leukocytosis, comprehensive metabolic panel to assess liver and kidney function, and blood cultures if sepsis is suspected. A urinalysis should also be performed to rule out urinary tract infection as a source. The CT scan will help identify the specific source of infection, determine if there are complications such as perforation or abscess formation, and guide further management decisions including the need for surgical intervention versus medical management with antibiotics.
Some may argue that alternative diagnostic approaches, such as ultrasound or MRI, can be used, especially in patients who cannot undergo CT-scan with IV-contrast 1. However, the study by Andeweg et al, as cited in 1, found that the pooled specificity of CT (96% [95% CI 90–100%]) was significantly higher compared with US (90% [95% CI 86–94%]). Therefore, CT scan remains the preferred imaging modality for diagnosing diverticulitis and other intra-abdominal infections.
Key points to consider when deciding on the next step in diagnosis include:
- The patient's symptoms and laboratory results, which suggest an intra-abdominal infection or inflammation
- The need to confirm the diagnosis and evaluate the extent of disease
- The potential for complications, such as perforation or abscess formation
- The availability and contraindications of different imaging modalities, such as CT scan, ultrasound, and MRI. In this case, given the patient's symptoms and laboratory results, a CT scan of the abdomen and pelvis with intravenous contrast is the most appropriate next step in diagnosis 1.
From the Research
Diagnostic Approach
The patient's symptoms of abdominal pain, fever, and leukocytosis suggest a possible diagnosis of diverticulitis. To confirm this diagnosis and assess the severity of the disease, imaging studies are necessary.
Imaging Studies
- Computed Tomography (CT) scan is the most appropriate next step in diagnosis, as it can confirm the presence of diverticulitis, evaluate the disease severity, and guide therapy planning 2, 3, 4.
- 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, 5.
CT Scan Findings
- The CT scan can show thickening of the intestinal wall, increase of the perivisceral fat density, and presence of diverticula in the pathological intestinal loop, which are characteristic findings of diverticulitis 2.
- The CT scan can also detect complications of diverticulitis, such as abscesses, intestinal perforation, and peritonitis 2, 3, 6.
Classification of Diverticulitis
- Diverticulitis can be classified as uncomplicated or complicated based on CT scan findings, severity of symptoms, and patient history 2, 3.
- Uncomplicated diverticulitis is defined as thickening of the intestinal wall with increase of the perivisceral fat density, while complicated diverticulitis is defined as presence of abscesses, intestinal perforation, or peritonitis 2.