Comparison of Ultrasonographic Finding in Men and Women Suspected of Acute Appendicitis: Usefulness and Limitation of Measurement of the Outer Diameter of the Vermiform Appendix.

Lee,  Eun Joo; Kim,  Soon; Oh,  Yoen Hee; Kim,  Seung Hyeon; Lee,  Sung Woo

Journal of Korean Society of Medical Ultrasound 2004;23(1): 5-10.

Eun Joo Lee, Soon Kim, Yoen Hee Oh, Seung Hyeon Kim, Sung Woo Lee

Department of Radiology, Gyeong Ju Hospital, Dongguk University School of Medicine, Korea. arrisu1052@hanmail.net

Published online: March 1, 2004.

ABSTRACT

PURPOSE: To evaluate the usefulness and limitations of measurement of the outer diameter of the vermiform appendix in men and women patients suspected of acute appendicitis on ultrasonography (US). MATERIALS AND METHODS: Retrospectively, the review of the outer diameter of the appendix measured in 197 adult patients, 70 men and 127 women (age ranged from 16 to 83 years), suspected of acute appendicitis on sustained-compression US was done. The measured outer diameters were categorized into two groups according to the patient's sex, and relationships between categoric variables were analyzed by calculating sensitivity, specificity, positive and negative predictive values and accuracy. Data analyses were performed using MedCalc for windows version 7.1.0.1. RESULTS: The outer appendiceal diameters in men ranged between 3.2 and 15 mm, while those in women, between 3.4 and 17 mm. The diameters of acute inflamed appendices ranged from 6 to 17 mm. In men, a diameter equal to or larger than 6 mm was confirmed as acute appendicitis with the sensitivity, specificity and positive and negative predictive values of 100%, 57.6%, 70.2% and 100%, respectively. Meanwhile, in women, a diameter of > or = 6 mm was confirmed as acute appendicitis with the sensitivity, specificity and positive and negative predictive values of 98%, 55.8%, 68.9% and 96.5%, respectively. The accuracy in women (67.7%) was lower than in men(75.7%), but no statistically significant difference (p=0.395) was seen between men and women. CONCLUSION: The outer appendiceal diameter of > or = 6 mm as a sign of acute appendicitis provides a high sensitivity and negative predictive values. This diagnostic criterion is more useful in excluding acute appendicitis than confirming it. There was no statistically significant difference in the accuracy between men and women.