Diagnostic Accuracy of Low Radiation Dose Contrast Enhanced Abdominal CT in Acute Appendicitis
Background: Acute appendicitis is one of the commonest causes of acute abdomen in emergency departments, of them most patients require surgery. However, at times the clinical diagnosis of appendicitis becomes challenging. Imaging modalities like ultrasound have been widely used for evaluating patients with suspicion of acute appendicitis, however ultrasound has many limitations. In the past decade there has been an increasing use of computed tomography (CT) for diagnosing acute appendicitis especially in adults. CT abdomen examination is of particular concern due to exposure to ionizing radiation. Studies have shown that low radiation dose CT (LDCT) examination also has high accuracy in diagnosing acute appendicitis.
Objective: The rationale of the present study is to determine the diagnostic accuracy of low radiation dose contrast enhanced abdominal CT in diagnosis of acute appendicitis taking histopathology as gold standard.
Study design, settings and duration: This cross sectional study was conducted at Accident & Emergency Department and Radiology Department of Combined Military Hospital, Rawalpindi from December 2015 to June 2016.
Methodology: Using Non-probability consecutive sampling, 185 patients fulfilling inclusion criteria were enrolled. An informed consent was taken from patients or attendants. Intravenous contrast-enhanced images were obtained with the use of multi-detector CT scanner. All patients were followed for their histopathology report and its results were compared with LDCT. Data was analyzed using SPSS version 20.
Results: The mean age of patients was 33.36±10.35 years with age range of 18-60 years. There were 101 (54.6%) male and 84 (45.4%) female patients. There were 106 true positive, 68 true negative, 5 false positive and 6 false negative patients. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy was 94.64%, 93.15%, 95.5%, 91.89% and 94.05% respectively. The patients aged 18-40 years, male had higher diagnostic accuracy.
Conclusion: This study shows that LDCT has high diagnostic accuracy. Thus in future we can alter our practice by adopting LDCT for diagnosis of acute appendicitis to avoid patients from excessive radiations exposure and no doubt it can also reduce hospital cost. This can be further justified with large scale studies.
(1) Indus Hospital, Lahore
(2) Department of Radiology, Rawalpindi Medical University/ Holy Family Hospital, Rawalpindi.
(3) Rawalpindi, Mayo Hospital, Lahore
(*) Corresponding Author