Skip to main content

Single institutional experience with initial ultrasound followed by computed tomography or magnetic resonance imaging for acute appendicitis in adults



The objectives of this study was to assess the performance of ultrasound (US) for suspected appendicitis in adult patients and to evaluated the additive value of short-interval (within 1 week) computed tomography (CT) or Magnetic Resonance Imaging (MRI) after performing an initial US.


In this IRB-approved, HIPAA-compliant, retrospective study, electronic medical records (EMRs) were queried for “US appendicitis” performed over a 2-year interval. EMR was reviewed for CT or MRI performed within 1 week of this exam, and if any new or additional information was available at subsequent exam. White count, patient disposition, and pathology, if surgery was performed, were also recorded.


682 patients underwent US for appendicitis over a 2-year duration, age range from 18 to 92 years (average: 30.1 years, M:F = 141:541). Findings showed 126/682 patients with normal appendix, 75/682 uncomplicated appendicitis, and 4/682 with complicated appendicitis. When performed, no additional findings were seen in these groups on short-interval CT or MRI. 2/682 patients had equivocal findings on US but eventually had normal appendix identified on CT. Four hundred and seventy-three patients had non-visualized appendix, of which only 14/473 (3.1%) eventually had appendicitis.


Ultrasound is an effective initial modality for evaluating appendicitis even in adult patients. Once a normal appendix, uncomplicated or complicated appendicitis is identified on US, no further imaging is necessary. Very few patients with non-visualization of the appendix eventually have appendicitis. Hence, these patients can be managed with active clinical follow-up rather than immediate CT or MRI. Symptoms and clinical scoring systems can be used for triage of these patients.

This is a preview of subscription content, access via your institution.

Fig. 1


  1. Expert Panel on Gastrointestinal, I., et al., ACR Appropriateness Criteria((R)) Right Lower Quadrant Pain-Suspected Appendicitis. J Am Coll Radiol, 2018. 15(11S): p. S373–S387.

  2. Ferris, M., et al., The Global Incidence of Appendicitis: A Systematic Review of Population-based Studies. Ann Surg, 2017. 266(2): p. 237-241.

    Article  PubMed  Google Scholar 

  3. Ramsay, G., J.M. Wohlgemut, and J.O. Jansen, Emergency General Surgery in the United Kingdom: A lot of General, not many Emergencies, and not much Surgery. J Trauma Acute Care Surg, 2018. Sep;85(3):500–506

  4. Drake, F.T., et al., Enteral contrast in the computed tomography diagnosis of appendicitis: comparative effectiveness in a prospective surgical cohort. Ann Surg, 2014. 260(2): p. 311-6.

    Article  PubMed  Google Scholar 

  5. Chiu, Y.H., et al., Whether intravenous contrast is necessary for CT diagnosis of acute appendicitis in adult ED patients? Acad Radiol, 2013. 20(1): p. 73-8.

  6. Repplinger, M.D., et al., Prospective Comparison of the Diagnostic Accuracy of MR Imaging versus CT for Acute Appendicitis. Radiology, 2018. 288(2): p. 467-475.

    Article  PubMed  Google Scholar 

  7. Balthazar, E.J., et al., Acute appendicitis: CT and US correlation in 100 patients. Radiology, 1994. 190(1): p. 31-5.

    Article  CAS  PubMed  Google Scholar 

  8. Doria, A.S., et al., US or CT for Diagnosis of Appendicitis in Children and Adults? A Meta-Analysis. Radiology, 2006. 241(1): p. 83-94.

    PubMed  Google Scholar 

  9. Poortman, P., et al., Comparison of CT and sonography in the diagnosis of acute appendicitis: a blinded prospective study. AJR Am J Roentgenol, 2003. 181(5): p. 1355-9.

    Article  PubMed  Google Scholar 

  10. Imler, D., et al., Magnetic Resonance Imaging Versus Ultrasound as the Initial Imaging Modality for Pediatric and Young Adult Patients With Suspected Appendicitis. Acad Emerg Med, 2017. 24(5): p. 569-577.

    Article  PubMed  Google Scholar 

  11. Eng, K.A., et al., Acute Appendicitis: A Meta-Analysis of the Diagnostic Accuracy of US, CT, and MRI as Second-Line Imaging Tests after an Initial US. Radiology, 2018. 288(3): p. 717-727.

    Article  PubMed  Google Scholar 

  12. Gaitini, D., et al., Diagnosing acute appendicitis in adults: accuracy of color Doppler sonography and MDCT compared with surgery and clinical follow-up. AJR Am J Roentgenol, 2008. 190(5): p. 1300-6.

    Article  PubMed  Google Scholar 

  13. Xu, Y., et al., Color Doppler Imaging of the Appendix: Criteria to Improve Specificity for Appendicitis in the Borderline-Size Appendix. J Ultrasound Med, 2016. 35(10): p. 2129-38.

    Article  PubMed  Google Scholar 

  14. Knoepp, U.S., et al., MR Imaging of Pelvic Emergencies in Women. Magn Reson Imaging Clin N Am, 2017. 25(3): p. 503-519.

    Article  PubMed  Google Scholar 

  15. Alzahrani, H., et al., Imaging Approach to the Diagnosis of Acute Appendicitis in a Group of Teaching Hospitals With 24/7 In-house Availability of Ultrasound Technologist: Effect of Timing of Request on Imaging Modality. Can Assoc Radiol J, 2018. Aug;69(3):311-315. Epub 2018 Jun 27.

  16. Koo, H.S., et al., Does computed tomography have any additional value after sonography in patients with suspected acute appendicitis? J Ultrasound Med, 2013. 32(8): p. 1397-403.

    Article  PubMed  Google Scholar 

  17. Li, J., et al., Effect of Delay to Operation on Outcomes in Patients with Acute Appendicitis: a Systematic Review and Meta-analysis. J Gastrointest Surg, 2018. Jan;23(1):210-223. Epub 2018 Jul 6.

  18. Gonzalez, D.O., et al., Can ultrasound reliably identify complicated appendicitis in children? J Surg Res, 2018. 229: p. 76-81.

    Article  PubMed  Google Scholar 

  19. Pelin, M., et al., Acute appendicitis: Factors associated with inconclusive ultrasound study and the need for additional computed tomography. Diagn Interv Imaging, 2018. Dec;99(12):809-814. Epub 2018 Sep 7.

  20. Daly, C.P., et al., Incidence of acute appendicitis in patients with equivocal CT findings. AJR Am J Roentgenol, 2005. 184(6): p. 1813-20.

    Article  PubMed  Google Scholar 

  21. Ganguli, S., et al., Right lower quadrant pain: value of the nonvisualized appendix in patients at multidetector CT. Radiology, 2006. 241(1): p. 175-80.

    Article  PubMed  Google Scholar 

  22. Nikolaidis, P., et al., The nonvisualized appendix: incidence of acute appendicitis when secondary inflammatory changes are absent. AJR Am J Roentgenol, 2004. 183(4): p. 889-92.

    Article  PubMed  Google Scholar 

  23. Srinivasan, A., et al., Utility of CT after sonography for suspected appendicitis in children: integration of a clinical scoring system with a staged imaging protocol. Emerg Radiol, 2015. 22(1): p. 31-42.

    Article  PubMed  Google Scholar 

  24. Kelly, B.S., et al., Improving diagnostic accuracy in clinically ambiguous paediatric appendicitis: a retrospective review of ultrasound and pathology findings with focus on the non-visualised appendix. Br J Radiol, 2018: Sep 12:20180585. [Epub ahead of print]

  25. Williamson, K., et al., Outcomes for Children With a Nonvisualized Appendix on Ultrasound. Pediatr Emerg Care, 2018. Nov 12. [Epub ahead of print]

  26. Stewart, J.K., E.W. Olcott, and R.B. Jeffrey, Sonography for appendicitis: nonvisualization of the appendix is an indication for active clinical observation rather than direct referral for computed tomography. J Clin Ultrasound, 2012. 40(8): p. 455-61.

    Article  PubMed  Google Scholar 

  27. Malia, L., et al., Diagnostic accuracy of laboratory and ultrasound findings in patients with a non-visualized appendix. Am J Emerg Med, 2018. Aug 7. pii: S0735-6757(18)30650-8. [Epub ahead of print]

  28. O’Malley, M.E., et al., CT following US for possible appendicitis: anatomic coverage. Eur Radiol, 2016. 26(2): p. 532-8.

    Article  PubMed  Google Scholar 

  29. Leeuwenburgh, M.M., et al., A simple clinical decision rule to rule out appendicitis in patients with nondiagnostic ultrasound results. Acad Emerg Med, 2014. 21(5): p. 488-96.

    Article  PubMed  Google Scholar 

  30. Leeuwenburgh, M.M., et al., Accuracy of MRI compared with ultrasound imaging and selective use of CT to discriminate simple from perforated appendicitis. Br J Surg, 2014. 101(1): p. e147-55.

    Article  CAS  PubMed  Google Scholar 

  31. Corkum, K.S., et al., Absolute neutrophil count as a diagnostic guide for the use of MRI in the workup of suspected appendicitis in children. J Pediatr Surg, 2018. Jun 22. pii: S0022-3468(18)30397-X. [Epub ahead of print]

  32. Jones, R.P., et al., Journal Club: the Alvarado score as a method for reducing the number of CT studies when appendiceal ultrasound fails to visualize the appendix in adults. AJR Am J Roentgenol, 2015. 204(3): p. 519-26.

    Article  PubMed  Google Scholar 

  33. Reddan, T., et al., Improving the value of ultrasound in children with suspected appendicitis: a prospective study integrating secondary sonographic signs. Ultrasonography, 2019 Jan;38(1):67-75. doi: 10.14366/usg.17062. Epub 2018 May 7.

    Article  PubMed  Google Scholar 

Download references

Author information

Authors and Affiliations


Corresponding author

Correspondence to Priyanka Jha.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Jha, P., Espinoza, N., Webb, E. et al. Single institutional experience with initial ultrasound followed by computed tomography or magnetic resonance imaging for acute appendicitis in adults. Abdom Radiol 44, 2357–2365 (2019).

Download citation

  • Published:

  • Issue Date:

  • DOI:


  • Appendicitis
  • Adults
  • Ultrasound
  • Follow-up
  • Computed tomography
  • Initial ultrasound