The Role of Ultrasound and CT Scan In Reducing Negative Appendectomy Rate

Maha Shaheen, Mariya Asghar, Hassan Tahir, Sheeraz Ur Rahman, Zahid Habib

  • Hassan Tahir Department of Surgery Liaquat National Hospital & Medical College Karachi



To assess the utility of ultrasound and CT scan abdomen and in patients with clinical diagnosis of acute appendicitis so as to reduce the negative appendectomy rate.

Study design

A retrospective observational study.

Place & Duration of study

Department of General Surgery, Liaquat National Hospital Karachi, from January 2016 to December 2020.


We reviewed the records of 440 patients who had an appendectomy at our institute. Of this 101 patients with incomplete records were excluded from final analysis. The primary outcome measure was the negative appendectomy rate. Descriptive statistics were applied and logistic regression analysis done to find out the relationship. Odds ratio were also calculated for multiple variables.


The negative appendectomy rate when computed tomography was used to aid in diagnosis was 2.08% and for ultrasound scan 5.89%. Logistic regression analysis suggested the superiority of computed tomography over ultrasound in the diagnosis of acute appendicitis with odds of 3.895 times when compared to ultrasound with odds of 1.949 times only.


Use of  computed tomography preoperatively for diagnosis of acute appendicitis can help in reducing the negative appendectomy rate.

Key words

Acute appendicitis, Ultrasonography, Computed tomography, Negative appendectomy rate.