PURPOSE: Diverticulitis is commonly diagnosed using CT. The major drawback of a CT scan is exposure to ionizing radiation that increases the risk of malignancy. Our aim was to determine the diagnostic accuracy of US compared with CT for patients suspected with diverticulitis, and to examine the possibility of using US as a primary tool in the emergency department for the diagnosis of diverticulitis.
METHODS: A double-blind, prospective analysis was conducted from December, 2015 – July, 2018 on 100 consecutive patients who were admitted to the emergency department suspected clinically for diverticulitis. Their medical history, clinical signs, and laboratory exams were reviewed. All patients underwent first ultrasound examination followed by an abdominal CT scan.
RESULTS: 91 patients were identified with colonic diverticulitis as the final diagnosis by CT compared to 88 by ultrasound. Sensitivity and specificity of the ultrasound examination were 96.7% (95% CI 90.7% - 99.3%) and 99.7% (95%CI 67%-100%), respectively.
The positive and negative predictive values for the diagnosis of simple diverticulitis by US were 99% and 75%, respectively. 11 patients were identified with complicated diverticulitis by CT compared to 10 patients by ultrasound. A tiny perforation was missed by the ultrasound. Sensitivity and specificity of the ultrasound examination for complicated diverticulitis were 91.7% and 99.7%, respectively. Positive and negative predictive values for the identification of complicated diverticulitis were 99% and 98.7%, respectively.
CONCLUSIONS: In our experience, US is a sensitive tool that can replace a CT scan in diagnosing simple diverticulitis. The CT can be reserved as a secondary tool in clinically non-resolved patients.
