Improvement in Diagnostic Accuracy of Ultrasound of the Pediatric Appendix Through the Use of Equivocal Interpretive Categories

Abstract

Appendix ultrasound examinations interpreted according to a scheme that incorporates equivocal categories better convey diagnostic certainty and increase diagnostic accuracy compared with a binary interpretive scheme.

Appendiceal ultrasound: the importance of determinacy

“…Similar numbers have been reported by Nielsen et al [5]. From their reported data, Larson et al [3] found that indeterminate US reports were 2.7 times more likely to have followup CT studies (55/123) than determinate US results (208/1,234), P<0.0001. Additionally, our negative laparotomy rate was significantly higher when an indeterminate US result was given than when a determinate result was given, 6.9% and 3.5%, respectively.…”

“…When the US report is indeterminate, clinicians will find determinacy in other ways and in many practices this means a CT study or an exploratory surgery. Our experience, as well as that of other investigators including Larson et al [3] bears this out. When our US reports were indeterminate, our patients had four times the rate of follow-up CTs and twice the rate of negative laparotomies.…”

“…Trout and Larson [1] concerning our article in this issue of Pediatric Radiology and the opportunity to further this discussion with a few additional thoughts. There are striking similarities between our two studies with respect to design and results but there are substantial differences in the conclusions drawn [2,3].…”

“…Trout and Larson [1] concerning our article in this issue of Pediatric Radiology and the opportunity to further this discussion with a few additional thoughts. There are striking similarities between our two studies with respect to design and results but there are substantial differences in the conclusions drawn [2,3].Patients referred for US evaluation for acute appendicitis have already been stratified into an indeterminate risk group based on their clinical data. Those thought to have a very high probability of acute appendicitis may be sent directly to surgery and those thought to have a very low probability of appendicitis often are not imaged at all.…”

“…Additionally, our negative laparotomy rate was significantly higher when an indeterminate US result was given than when a determinate result was given, 6.9% and 3.5%, respectively. Larson et al [3] reported a 17.9% negative laparotomy rate but did not indicate the rate for determinate and indeterminate US results separately.…”