Article Text

Download PDFPDF
Refining sonographic criteria for paediatric appendicitis: combined effects of age-based appendiceal size and secondary findings
  1. Jeffrey T Neal1,
  2. Michael C Monuteaux1,
  3. Shawn J Rangel2,
  4. Carol E Barnewolt3,
  5. Richard G Bachur1
  1. 1 Division of Emergency Medicine, Boston Children’s Hospital, Boston, Massachusetts, USA
  2. 2 Department of Surgery, Boston Children’s Hospital, Boston, Massachusetts, USA
  3. 3 Department of Radiology, Boston Children’s Hospital, Boston, Massachusetts, USA
  1. Correspondence to Dr Jeffrey T Neal, Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA; jeffreytneal{at}


Objective Appendiceal diameter is a primary sonographic determinant of paediatric appendicitis. We sought to determine if the diagnostic performance of outer appendiceal diameter differs based on age or with the addition of secondary sonographic findings.

Methods We retrospectively reviewed patients aged less than 19 years who presented to the Boston Children’s Hospital ED and had an ultrasound (US) for the evaluation of appendicitis between November 2015 and October 2018. Our primary outcome was the presence of appendicitis. We analysed the cases to evaluate the optimal outer appendiceal diameter as a predictor for appendicitis stratified by age (<6, 6 to <11, 11 to <19 years), and with the addition of one or more secondary sonographic findings.

Results Overall, 945 patients met criteria for inclusion, of which 43.9% had appendicitis. Overall, appendiceal diameter as a continuous measure demonstrated excellent test performance across all age groups (area under the curve (AUC) >0.95) but was most predictive of appendicitis in the youngest age group (AUC=0.99 (0.98–1.00)). Although there was no significant difference in optimal diameter threshold between age groups, both 7- and 8-mm thresholds were more predictive than 6 mm across all groups (p<0.001). The addition of individual (particularly appendicolith or echogenic fat) or combinations of secondary sonographic findings increased the diagnostic value for appendicitis above diameter alone.

Conclusions Appendiceal diameter as a continuous measure was more predictive of appendicitis in the youngest group. Across all age groups, the optimal diameter threshold was 7 mm for the diagnosis of paediatric appendicitis. The addition of individual or combination secondary sonographic findings increases diagnostic performance.

  • pediatric emergency medicine
  • pediatrics
  • ultrasonography
  • abdomen

Data availability statement

Data are available on reasonable request. Not a clinical trial.

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

Data availability statement

Data are available on reasonable request. Not a clinical trial.

View Full Text


  • Handling editor Shammi L Ramlakhan

  • Twitter @jeffreytneal

  • Presented at The abstract of this article was previously accepted and presented as a poster presentation at the Proceedings of the 2021 Pediatric Academic Societies Annual Meeting in May of 2021, which was virtual due to the COVID-19 pandemic.

  • Contributors JTN and RGB conceived the study, submitted the appropriate institutional review board paperwork and supervised the data collection and analysis. JTN, RGB and CEB undertook acquisition and management of data, including quality control, as well as review of the analysis. CEB provided protocol advice and facilitated acquisition of US data. MCM provided additional protocol advice including statistical recommendations. JTN drafted the manuscript, and RGB takes responsibility for the paper as a whole. All authors contributed substantially to the manuscript review and revision. All authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work. JTN is the guarantor of the manuscript.

  • Funding This work was supported by the Dr Michael Shannon Emergency Medicine Award (Boston Children’s Hospital) to JTN. Data collection for this study was partially funded by an internal grant, the Dr Michael Shannon Emergency Medicine Award (Boston Children’s Hospital).

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.