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Acute appendicitis: prospective evaluation of a diagnostic algorithm integrating ultrasound and low-dose CT to reduce the need of standard CT

  • Emergency Radiology
  • Published:
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Abstract

Objectives

To evaluate an algorithm integrating ultrasound and low-dose unenhanced CT with oral contrast medium (LDCT) in the assessment of acute appendicitis, to reduce the need of conventional CT.

Methods

Ultrasound was performed upon admission in 183 consecutive adult patients (111 women, 72 men, mean age 32) with suspicion of acute appendicitis and a BMI between 18.5 and 30 (step 1). No further examination was recommended when ultrasound was positive for appendicitis, negative with low clinical suspicion, or demonstrated an alternative diagnosis. All other patients underwent LDCT (30 mAs) (step 2). Standard intravenously enhanced CT (180 mAs) was performed after indeterminate LDCT (step 3).

Results

No further imaging was recommended after ultrasound in 84 (46%) patients; LDCT was obtained in 99 (54%). LDCT was positive or negative for appendicitis in 81 (82%) of these 99 patients, indeterminate in 18 (18%) who underwent standard CT. Eighty-six (47%) of the 183 patients had a surgically proven appendicitis. The sensitivity and specificity of the algorithm were 98.8% and 96.9%.

Conclusions

The proposed algorithm achieved high sensitivity and specificity for detection of acute appendicitis, while reducing the need for standard CT and thus limiting exposition to radiation and to intravenous contrast media.

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Acknowledgement

This paper was supported by the grant for Research and Development of the University Hospital of Geneva (PRD-03-II-15).

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Authors and Affiliations

  1. Department of Radiology, University Hospital of Geneva, 4 rue Gabrielle Perret-Gentil, 1211, Genève-14, Switzerland

    Pierre-Alexandre Poletti, Alexandra Platon, Thomas De Perrot & Christoph D. Becker

  2. Emergency Center, University Hospital of Geneva, Geneva, Switzerland

    Pierre-Alexandre Poletti, Alexandra Platon, Francois Sarasin, Elisabeth Andereggen & Olivier Rutschmann

  3. Division of Clinical Epidemiology, University Hospital of Geneva, Geneva, Switzerland

    Elise Dupuis-Lozeron & Thomas Perneger

  4. Department of Surgery, University Hospital of Geneva, Geneva, Switzerland

    Elisabeth Andereggen & Pascal Gervaz

Authors
  1. Pierre-Alexandre Poletti
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  2. Alexandra Platon
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  3. Thomas De Perrot
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Correspondence to Pierre-Alexandre Poletti.

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Poletti, PA., Platon, A., De Perrot, T. et al. Acute appendicitis: prospective evaluation of a diagnostic algorithm integrating ultrasound and low-dose CT to reduce the need of standard CT. Eur Radiol 21, 2558–2566 (2011). https://doi.org/10.1007/s00330-011-2212-5

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  • DOI: https://doi.org/10.1007/s00330-011-2212-5

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