Multi-Detector Computed Tomography Evaluation of Normal Appendix.

Background Appendix is a blind-ended tubular structure arising from caecum, with variable intraluminal contents and position. Acute appendicitis is one of the common indications for emergency radiological investigation. Objective To assess visualization rate, size and position of normal appendix by Computed Tomography (CT). Method This cross-sectional observational study was done in 198 individuals undergoing abdominal CT without suspicion of acute appendicitis and without any pathology localized within right iliac fossa. Axial and coronal reformatted images of nonenhanced and contrast enhanced CT of abdomen were evaluated for visualization of appendix. Visualized appendices arising from caecum were traced and tip localized. Contents within the appendicular lumen were also evaluated and maximum transverse diameter of appendix measured. The relationship between appendicular diameter, intraluminal content and position with different age groups & gender were also derived. Result Visualization rates of appendix were 90% (93% male and 87% female) in nonenhanced CT and 97% (99.8% male and 95.4% female) in enhanced CT. The mean diameter of the appendix was 6.2 ± 1.16 mm. Most common location of the tip of appendix was pelvic position, followed by retrocaecal position. Most of the appendices showed intraluminal air. Conclusion Multi-Detector Computed Tomography is superior over ultrasonography (USG) in detection of appendix. Modifications of CT protocol reduce limitations of CT over ultrasound in evaluation of appendix. Ultrasound size criteria for appendicitis (>6 mm) is not applicable in CT as normal appendix can measure >6 mm in CT.