A Prospective Evaluation of Point-of-Care Ultrasonographic Diagnosis of Diverticulitis in the Emergency Department

We evaluate the sensitivity and specificity of point-of-care ultrasonography, performed by ultrasonographic fellowship–trained emergency physicians and physician assistants, compared with computed tomography (CT) scan in diagnosing acute diverticulitis in the emergency department (ED). This was a prospective observational study of a convenience sample of patients with suspected diverticulitis who were treated at an academic ED between 2017 and 2020. Sonographers were blinded to clinical data, laboratory results, and CT scan findings. A total of 19 ultrasonographic fellowship–trained emergency physicians and physician assistants performed the ultrasonographic examinations. Point-of-care ultrasonographic diagnosis of acute diverticulitis was defined as the presence of bowel wall thickening, greater than 5 mm, surrounding a diverticulum, enhancement of the surrounding pericolonic fat, and sonographic tenderness to palpation. The primary outcome measures were sensitivity, specificity, positive predictive value, and negative predictive value of point-of-care ultrasonography in the diagnosis of diverticulitis compared with CT, which was considered the criterion standard. Data from 452 patients were analyzed. Median age was 60 years, 54% were women, and 36% had a diagnosis of diverticulitis based on CT scan. Of the 452 patients, there were 13 false-positive (3%) and 10 false-negative (2%) point-of-care ultrasonographic examinations. Overall, compared with CT, point-of-care ultrasonography had a sensitivity of 92% (95% confidence interval 88% to 96%), specificity of 97% (95% confidence interval 94% to 99%), positive predictive value of 94% (95% confidence interval 90% to 97%), and negative predictive value of 96% (93% to 98%) in the diagnosis of diverticulitis. In a convenience sample of ED patients with suspected diverticulitis, point-of-care ultrasonography performed by ultrasonographic fellowship–trained emergency physicians and physician assistants could be used as an imaging modality for diagnosing acute diverticulitis, with high sensitivity and specificity compared with CT scan.