From the Guidelines
The best diagnostic tool for identifying diverticulitis is a CT scan of the abdomen and pelvis with intravenous and oral contrast, as it provides detailed visualization of the bowel wall, surrounding fat stranding, and potential complications with high sensitivity and specificity, as reported in the most recent study by 1. This imaging modality is preferred due to its reproducibility, superior diagnostic accuracy, and ability to risk-stratify patients for operative versus nonoperative treatment. When a patient presents with symptoms like lower abdominal pain (typically left-sided), fever, and altered bowel habits, the CT scan can confirm the diagnosis with high sensitivity (98%) and specificity, as noted in the study by 1. Some key points to consider when using CT scans for diverticulitis diagnosis include:
- The use of IV contrast material to improve the characterization and detection of subtle bowel wall abnormalities and complications of diverticulitis, as mentioned in the study by 1.
- The potential for unenhanced CT to be used in patients with contraindication to IV contrast material, as noted in the study by 1.
- The ability of CT to predict which patients are likely to experience recurrent diverticulitis, as reported in the study by 1. Laboratory tests, including complete blood count to check for leukocytosis and C-reactive protein to assess inflammation, should accompany imaging but are not diagnostic on their own. While ultrasound may be used in certain populations (pregnant patients or young patients to limit radiation exposure), it is operator-dependent and less reliable, as mentioned in the study by 1. Colonoscopy is generally avoided during acute diverticulitis due to the risk of perforation but may be performed 6-8 weeks after resolution to rule out other conditions like colorectal cancer. The CT scan's ability to detect inflammatory changes in the colonic wall and surrounding tissues makes it the gold standard for diverticulitis diagnosis in clinical practice, as supported by the studies by 1, 1, and 1.
From the Research
Diagnostic Methods for Diverticulitis
- Computed Tomography (CT) is widely accepted as the best imaging method for evaluating diverticular inflammation 2
- CT scan with intravenous contrast administration is considered the gold standard for diagnosing diverticulitis 3, 4
- 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 abscess or perforation 5
CT Scan Findings
- The presence of diverticula in the pathological intestinal loop is a key finding in differentiating diverticulitis from other inflammatory diseases 2
- CT scan findings can be used to classify diverticulitis as complicated or uncomplicated, guiding management decisions 2, 6
- Specific CT criteria, such as pericolic infiltration, presence of lymph nodes, and inflamed diverticula, can help differentiate colonic diverticulitis from colon cancer 4
Management and Follow-up
- Radiological evidence of inflammation using CT is needed to diagnose the first occurrence of diverticulitis 6
- CT scan is warranted when the severity of symptoms suggests perforation or abscesses have occurred 6
- Follow-up colonoscopy is recommended for patients with complicated diverticulitis or those with suspicious features on CT scan 3, 6