Effectiveness of a Routine Ultrasonography and Limited Multidetector Computed Tomography Imaging Protocol for Evaluation of Adult Patients With Clinically Suspected Acute Appendicitis

Aim: To study the accuracy of a routine Ultrasonography(US) and limited Multidetector Computed Tomography(MDCT) protocol for imaging patients with suspected acute appendicitis. Materials And Methods: In this observational study approved by the Institutional Review Board (November 2015 to March 2017), 98 adult patients with suspected acute appendicitis(AA) underwent US, which was categorized as positive, negative or equivocal for AA. US positive cases were also categorized as complicated/ uncomplicated appendicitis. MDCT was performed in all US equivocal cases, and a nal imaging diagnosis- either positive or negative for AA- was given. Imaging diagnoses were correlated with operative/histopathological ndings, or clinical follow-up. Among 98 suspected cases Results: , 71(72.4%) were nally diagnosed as AA. 60 cases were US positive, 19 US negative and 19 equivocal on US. CT was performed in all 19 equivocal cases, along with 7 US positive cases (to assess complications) and 1 US negative case (bowel lymphoma). CT was avoided in 71/98 cases. Overall, the imaging protocol (US ± CT) showed sensitivity of 98.3%, specicity 96.3%, PPV 98.6%, NPV 96.3% for the diagnosis of AA. US identied 60 AA positive cases, with 36 labeled as uncomplicated and 24 complicated AA. Among operated US-positive patients, sensitivity and specicity for complicated AA were 77.8% and 89.3%. Overall imaging accuracy for complicated AA: sensitivity 85.7%, specicity 90.5%, PPV 85.7%, NPV 88.4%. Conclusion: An imaging protocol that employs initial US in all suspected cases, followed by CT only in US equivocal cases, shows high sensitivity and specicity for the diagnosis of acute appendicitis, while reducing the number of CT examinations.