Increased Renal Echogenicity in Children With Appendicitis

Ultrasound (US) is an important modality for the detection of acute appendicitis in children but has limited sensitivity and specificity. Therefore, additional US findings may contribute to the diagnosis. In our experience, children with acute appendicitis often have increased renal cortical echogenicity on US imaging. The purpose of this study was to examine the association of increased renal cortical echogenicity with appendicitis.

This study included 240 consecutive pediatric patients with no renal or liver disease who underwent US examinations for suspected appendicitis between February 2014 and January 2016. Ultrasound images of the liver and right kidney were retrospectively reviewed, and the echogenicity of the renal cortex was classified as less than the liver, equal to the liver, or greater than the liver.

The renal cortex was abnormally hyperechoic in 38 (50%) of all of the patients who had appendicitis according to US (P < .001) and in 47% of patients who underwent appendectomy (P = .002). Overall, 36% of patients with increased renal cortical echogenicity had a diagnosis of appendicitis. After correction for variables, patients with renal hyperechogenicity had a 2.5 times chance of appendicitis (odds ratio, 2.5).

There is a statistically significant association between increased renal cortical echogenicity and appendicitis. In the absence of hepatic or renal disease, this finding may increase the accuracy of the US diagnosis of appendicitis. Increased renal cortical echogenicity may be added to the list of US findings accompanying acute appendicitis in children.