An evaluation of individual plain abdominal radiography findings in pediatric appendicitis: results from a series of 424 children.

Background: This study was conducted to collect the results of the plain abdominal radiography (PAR) signs, to determine their individual diagnostic values, and to discuss them under a brief literature review.

Methods: Eight predetermined PAR signs were individually interpreted in a series of 424 consecutive children (278 males; 146 females; median age 10 years; range 11 months to 17 years) who underwent an operation for appendicitis. The sensitivity, specificity, and positive and negative predictive values for the signs were determined.

Results: Appendicitis was confirmed in 378 (89%) patients. Among the remaining 46 (11%) patients with a normal appendix, 20 (5%) had other intraabdominal pathologies. Calcified fecalith, mass image in right-lower-quadrant (RLQ), psoas obscuration, and localized extraluminal air signs were all highly specific and therefore, unlikely to be present if the appendix is normal. On the other hand, the sensitivity values were low, in general, for all the PAR signs investigated. Yet, presence of dilated transverse colon and/or single air fluid level in the RLQ has the highest percentage occurrence with appendicitis.

Conclusion: Although the there is no single PAR finding capable of ruling the diagnosis of appendicitis out, basic knowledge on PAR findings could have an impact on decision making process for clinicians dealing with pediatric acute abdominal pain.