The Reliability of a Standardized Reporting System for the Diagnosis of Appendicitis

Abstract

Purpose Computed tomography (CT) is a fast and ubiquitous tool to evaluate intra-abdominal organs and diagnose appendicitis. However, traditional CT reporting does not necessarily capture the degree of uncertainty and indeterminate findings are still common. The purpose of this study was to evaluate the reproducibility of a standardized CT reporting system for appendicitis across a large population and the system’s impact on radiologists’ certainty in diagnosing appendicitis. Methods Using a previously described standardized reporting system, eight radiologists retrospectively evaluated CT scans in a cohort of 561 patients imaged for possible appendicitis (2010–2014). Based on the original reports, 159 of these scans were selected to be over-read by a second reviewer. Reproducibility of reporting and certainty in the diagnosis of appendicitis was compared between the radiologists, and correlation made with clinical diagnoses. Results Appendicitis occurred in 20% of patients (mean age 38, 67% male) in the overall cohort (n=113 of 561). Using the standardized report, radiologists were highly accurate at identifying appendicitis (AUC=0.968, 95%CI: 0.95, 0.99), which occurred in 48% of selected exams (113 of 237). Inter-reader agreement was >80% for most objective findings, and certainty in diagnosing appendicitis was high and reproducible (AUC=0.955 and AUC=0.936 for primary readers and over-readers, respectively). In the subgroup of patients with previously “indeterminate” reports, 57% (24 of 42) were assigned the correct diagnosis using the standardized report. Conclusions Using a standardized reporting system resulted in high reproducibility of objective CT findings for appendicitis and achieved high diagnostic accuracy in an at-risk population. Predictive tools based on this reporting system may further improve communication about certainty in diagnosis and guide patient management, especially when CT findings are indeterminate.

A randomised placebo-controlled double-blind multicentre trial comparing antibiotic therapy with placebo in the treatment of uncomplicated acute appendicitis: APPAC III trial study protocol

“…The used CT protocols (low dose or standard) are thoroughly recorded and the radiologist use a standardised CT scan report sheet ( box 1 ) in order to facilitate standardisation of the diagnostic imaging, which has been shown to result in high reproducibility of objective CT findings achieving high diagnostic accuracy in an at-risk population. 41 This standardised recording enables thorough assessment of the accuracy of diagnostic CT imaging (low dose and/vs standard) used in this study, as well as the retrospective analysis of the accuracy of the existing scoring systems with clinical and laboratory findings used for diagnosing acute appendicitis. In our APPAC study, cost-effectiveness results comparing antibiotics or appendectomy, the imaging costs were a minor portion of the total costs of either treatment 32 and the use of CT scan has been shown to markedly reduce the treatment costs by avoiding unnecessary negative appendectomies.…”

Reliability of Standardized Reporting System of acute appendicitis in adults at low-dose 320-rows CT

“…In this study, there is excellent inter-observer agreement of appendicolith and presence of gas or contrast medium within the lumen of appendix. Previous studies reported that appendicolith is well-de ned, hyperdense non-enhancing structure that strongly associated with advanced appendicitis and is a risk factor for peroration and necrosis (24)(25)(26)(27)(28). Another studies reported that presence of gas within the lumen of appendix is a sign of acute appendicitis and the presence of oral contrast material within the appendix con icts with a diagnosis of acute appendicitis and can be used as supporting evidence for a nonobstructed appendix in equivocal cases (24)(25)(26)(27)(28).…”

“…Phlegmon was de ned as diffuse and substantial in ammation of the periappendiceal fat with ill-de ned but not rim-enhancing uid collections and abscess is de ned as a discrete collection with rim enhancement (15)(16)(17). Another study added that peri-appendiceal uid collection revealed area under the curve of 0.80, sensitivity of 77%, and accuracy of 80% and the highest speci city (100%) is recorded for the presence of extraluminal air and a perityphlitic abscess (27). Another study added that the peri-appendiceal fat stranding is the only feature with high sensitivity (94%) for diagnosis of acute appendicitis (17).…”

“…Different ultrasound scoring system applied for prediction of appendicitis (23)(24). Also, few studies reported a role of different scoring system of CT in diagnosis of acute appendicitis (25)(26)(27)(28)(29)(30). Standardized reporting system of acute appendicitis using CT with developed for diagnosis of acute appendicitis in patients with abdominal pain (25)(26).…”

Optimising the antibiotic treatment of uncomplicated acute appendicitis: a protocol for a multicentre randomised clinical trial (APPAC II trial)

“…A recent radiological meta-analysis [22] stated specific CT imaging features most informative for complicated appendicitis and all these CT findings are used also as criteria for complicated appendicitis in the current APPAC II study. The used CT protocols (low-dose or standard) are thoroughly recorded and the radiologists use a standardised CT scan report sheet (Table 1) in order to facilitate standardisation of the diagnostic imaging, which has been shown to result in high reproducibility of objective CT findings achieving high diagnostic accuracy in an at-risk population [46]. This standardised recording enables thorough assessment of the accuracy of diagnostic CT imaging (low-dose and/vs.…”