Size matters: Computed tomographic measurements of the appendix in emergency department scans

• Published in: The American journal of surgery Vol. 218; no. 2; pp. 271 - 274
• Main Authors: Moskowitz, Eliza, Khan, Abid D., Cribari, Chris, Schroeppel, Thomas J.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.08.2019; Elsevier Limited
• Subjects: Abdomen; Adult; Adults; Age; Appendectomy; Appendicitis; Appendicitis - diagnostic imaging; Appendix; Appendix - diagnostic imaging; Appendix - pathology; Body mass; Body mass index; Computed tomography; Demographic variables; Demographics; Demography; Emergency medical services; Emergency Service, Hospital; Female; Humans; Male; Medical imaging; Medical personnel; Middle Aged; Obesity; Organ Size; Pain; Patients; Retrospective Studies; Stranding; Studies; Tomography, X-Ray Computed; Colorado
• DOI: 10.1016/j.amjsurg.2018.12.010
• ISSN: 0002-9610

Radiologists use a size cutoff in appendiceal diameter to assist surgeons in diagnosing appendicitis, however, no consensus exists as to the size of a normal adult appendix. We aim to evaluate radial appendiceal diameter on CT in adult patients both with and without appendicitis. Retrospective review of adults who underwent abdominal CT was performed. Variables collected include: demographics, BMI, WBC count at presentation, radial diameter of appendix (mm), presence of fat stranding, fecalith, and free fluid. During the study period, 3099 patients underwent CT. The appendix was visualized on 74% of scans. Mean appendiceal diameter was 6.6 mm (±1.7). The appendix was larger in patients with appendicitis (6.6 vs. 11.4; p < 0.0001). Overall appendectomy incidence was 3.2%. Sensitivity and specificity of CT in diagnosing appendicitis in this cohort of patients were 90% and 94%. NPV was 99.5%. While appendiceal diameter was larger in patients with appendicitis, >20% of patients without appendicitis had an appendiceal diameter >7 mm. Diameter alone should not be relied upon to diagnose appendicitis. •Improvements in CT technology have augmented the ability to diagnose appendicitis radiographically.•Radiologists use a size cutoff in the radial diameter of the appendix to assist in the diagnosis of appendicitis.•While there is agreement regarding the size of a normal pediatric appendix, there is no consensus as to the true size of a normal adult appendix.•.•While radial appendiceal diameter was larger in patients with appendicitis, greater than 20% of patients without appendicitis had an appendiceal diameter larger than 7 mm.•Relying only on appendiceal diameter for the diagnosis of acute appendicitis may lead to an increased rate of negative appendectomies.