Assessment of Diagnostic Radiology Methods Effectiveness in Acute Appendicitis Diagnosis in the Emergency Department

Objective: To assess the effectiveness of ultrasonography and contrast-enhanced computed tomography (CT) in diagnosing acute appendicitis.

Material and methods: The study group included 912 patients with suspected acute appendicitis who underwent imaging and surgery. The inclusion criterion is the availability of histopathological findings. To assess the diagnostic effectiveness, we determined sensitivity (Se), specificity (Sp), accuracy (Ac), and positive (PPV) and negative (NPV) predictive values using the corresponding formulas. Statistical analyses were performed using MedCalc, version 20.013 (MedCalc Software Ltd, Belgium). The diagnostic effectiveness is presented as receiver operating characteristic curves.

Results: Preoperative imaging enabled to establish the correct diagnosis of acute appendicitis in 92.4% of patients. The diagnostic effectiveness of ultrasonography in the study group (n=912) was Se, 68.34%; Sp, 56.5%; Ac, 67.4%; PPV, 95%; NPV, 12.9%; that of contrast-enhanced CT, Se, 94.4%; Sp, 76.9%; Ac, 92.5%; PPV, 97.1%; NPV, 62.5%. The appendiceal diameter cutoff was >6.8 mm for ultrasonography, with Se of 91.3% and Sp of 57.1%, area under the curve (AUC), 0.720 (P >6.6 mm for contrast-enhanced CT, with Se of 95.5% and Sp of 83.3%, AUC, 0.966 (P <.0001).

Conclusions: Ultrasonography has sufficient diagnostic effectiveness as the first-line imaging in patients with suspected acute appendicitis. Contrast-enhanced CT has higher effectiveness in diagnosing acute appendicitis and should be used in patients with negative ultrasonography findings, high risk of complicated acute appendicitis and as an additional tool for differential diagnosis.

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