Computed tomography localization of the appendix in the pediatric population relative to the lumbar spine

Abstract

Background: Computed tomography (CT) is commonly used to evaluate suspected acute appendicitis. Although very effective, CT uses ionizing radiation, exposing patients to an increased risk of cancer.

Objective: This study assessed the potential for decreasing the field of view of the CT (and therefore the dose to the patient) in the evaluation of suspected acute appendicitis in children.

Materials and methods: This study was a retrospective review of prospectively collected data from 212 consecutive patients who underwent CT for suspected acute appendicitis. The most superior aspect of the appendix with respect to vertebral bodies was recorded. Age, gender and diagnosis (negative, acute appendicitis or alternative diagnosis) were noted.

Results: The appendix was visualized in 190 of 212 subjects (89.6%). Overall, all visualized appendixes were located at or below the level of L1. Sixty-three of the subjects (29.7%) were diagnosed with acute appendicitis via CT imaging. All appendixes in patients with acute appendicitis were located at or below the level of the L3 vertebral body, predominating at the level of L5. Six subjects (3.1%) received alternative diagnoses, including pneumonia, pyelonephritis, small bowel obstruction and infected urachal cyst. There were no differences in appendix location with regard to diagnosis, gender, or age (P=0.664, 0.748 and 0.705, respectively).

Conclusion: CT field of view may be decreased to the level of L1 or L3 superiorly, decreasing radiation dose without affecting the rate of appendix visualization.

Keywords: Acute appendicitis; Appendix; Children; Computed tomography; Radiation.