Researchers develop standardized reporting system to improve accuracy of appendicitis imaging

A novel system of standardized reporting and image analysis has shown the potential to help improve the accuracy of appendicitis imaging and decrease the rate of unnecessary surgical procedures, according to results of a study published in the June issue of the American Journal of Roentgenology.

CT scans have dramatically improved diagnostic accuracy regarding appendicitis in the past 20 years, reducing the number of negative laparotomies to a rate of less than 10 percent. Despite its effectiveness, there remain some instances where CT findings are equivocal or inconclusive, according to lead author Benjamin Godwin, MD, and his colleagues at the University of Washington in Seattle. “Because the diagnosis of appendicitis on CT is not always certain, a clear way of expressing the likelihood of appendicitis is needed,” wrote the authors. “This can be achieved by linking imaging findings with certainty scores; categorizing imaging findings as positive, negative, or indeterminate for appendicitis; or weighing imaging findings on the basis of clinical concern.”

The researchers developed a novel systematic approach to using CT examination for the diagnosis of appendicitis, then set out to assess its diagnostic accuracy and reproducibility. To do so, they asked four radiologists to retrospectively review preoperative CT scans of 96 appendectomy patients at the researchers’ medical facility using the new standardized reporting system. A certainty score ranging from 1 (definitely not appendicitis) through 5 (definitely appendicitis) was used to evaluate each patient before comparing the imaging findings and certainty scores to the final pathology.

Their results confirmed that appendiceal diameter, periappendiceal fat stranding and appendiceal mucosal hyperenhancement are imaging findings strongly correlated with the presence of appendicitis on final pathology. They also found that radiologists using their standardized reporting system were effective in assigning higher certainty scores (4 or 5) in 75 percent of patients with appendicitis, while alternately assigning lower scores (1 or 2) in 71 percent of patients without appendicitis. “Standardized reporting and grading of objective imaging findings correlated well with postoperative pathology and may decrease the number of CT findings reported as indeterminate for appendicitis,” wrote Godwin and colleagues. “Our data suggest that the likelihood for appendicitis can be more confidently based on the presence or absence of specific imaging findings, rather than relying on overall gestalt.”

Despite its early successes, the reporting system requires more in-depth testing, noted the researchers, who report that additional studies are already underway. “[F]urther development and adoption of a standardized reporting format may continue to improve accuracy of appendicitis diagnosis, increase the quality of radiologist-clinician communication, and ultimately optimize patient management,” the authors wrote. “Prospective evaluation of this reporting system on a cohort of patients with clinically suspected appendicitis is currently under way.”