Reliability of ultrasonography in the diagnosis of acute appendicitis


  • Thomas George Department of General Surgery, Pushpagiri Institute of Medical Sciences, Tiruvalla, Kerala, India
  • Rajan Babu K.N. Department of General Surgery, Pushpagiri Institute of Medical Sciences, Tiruvalla, Kerala, India
  • Thomas P. T. Department of General Surgery, Pushpagiri Institute of Medical Sciences, Tiruvalla, Kerala, India



Ultrasonography, Appendicitis, Negative appendicectomy rate


Background: Ultrasonography (US) is a commonly used investigation for diagnosing appendicitis. Although previous studies have shown US to be less sensitive than CT, proceeding with appendicectomy for all patients with positive US for appendicitis can save valuable time and cost. The aim of this study is to determine the value of a positive US for appendicitis and the outcome of operating on all these patients.

Methods: This is a retrospective analysis of a cohort of 200 consecutive patients who underwent appendicectomy due to a positive US diagnosis of appendicitis, between January 2014 and November 2015. Their histopathology reports were analysed to determine the number of patients with histological evidence of appendicitis.

Results: 179 out of the 200 patients showed a positive evidence of appendicitis on histology. This equates to a Positive Predictive Value (PPV) of 89.5% and a Negative Appendicectomy Rate (NAR) of 10.5% in these patients.

Conclusions: In our centre, we felt it was justified to operate on patients with a positive US for appendicitis due to a high PPV and low NAR. Furthermore, US have the added benefits of being less expensive, easy to do, repeatable and rapid to complete. Thus, we recommend that in centres such as ours where ultrasonography is available all the time, a positive US should be the first investigation of choice for deciding operative management. Patients with an equivocal US diagnosis should be monitored with further clinical assessment and CT scan.


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Original Research Articles