title: How to diagnose acute appendicitis: ultrasound first.
abstract: Acute appendicitis (AA) is a common abdominal emergency with a lifetime prevalence of about 7 %. As the clinical diagnosis of AA remains a challenge to emergency physicians and surgeons, imaging modalities have gained major importance in the diagnostic work-up of patients with suspected AA in order to keep both the negative appendectomy rate and the perforation rate low. Introduced in 1986, graded-compression ultrasound (US) has well-established direct and indirect signs for diagnosing AA. In our opinion, US should be the first-line imaging modality, as graded-compression US has excellent specificity both in the paediatric and adult patient populations. As US sensitivity is limited, and non-diagnostic US examinations with non-visualization of the appendix are more a rule than an exception, diagnostic strategies and algorithms after non-diagnostic US should focus on clinical reassessment and complementary imaging with MRI/CT if indicated. Accordingly, both ionizing radiation to our patients and cost of pre-therapeutic diagnosis of AA will be low, with low negative appendectomy and perforation rates. Main Messages • Ultrasound (US) should be the first imaging modality for diagnosing acute appendicitis (AA). • Primary US for AA diagnosis will decrease ionizing radiation and cost. • Sensitivity of US to diagnose AA is lower than of CT/MRI. • Non-visualization of the appendix should lead to clinical reassessment. • Complementary MRI or CT may be performed if diagnosis remains unclear.
authors.affiliation: Department of Radiology, Wilhelminenspital, Montleartstr., 37 1160, Vienna, Austria. gerhard.mostbeck@chello.at.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Mostbeck
authors.affiliation: St George's Hospital, Blackshaw Road, SW17 0QT, London, UK.
authors.forename: E Jane
authors.initials: EJ
authors.lastname: Adam
authors.affiliation: Department of Radiology, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark.
authors.forename: Michael Bachmann
authors.initials: MB
authors.lastname: Nielsen
authors.affiliation: Children Hospital, University Hospital-Nancy Brabois, Rue du Morvan, 54511, Vandoeuvre Les Nancy Cedex, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Claudon
authors.affiliation: Munich University Hospital, Marchioninistraße. 15, 81377, München, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Clevert
authors.affiliation: Radiology Department, Hospital Clinic, Villarroel 170, 08036, Barcelona, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Nicolau
authors.affiliation: Radiology Department, City Hospitals Sunderland FT, Kayll Road, Sunderland, SR4 7TP, UK.
authors.forename: Christiane
authors.initials: C
authors.lastname: Nyhsen
authors.affiliation: Department of Radiology, Great Ormond Street, WC1N, 3JH, London, UK.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Owens
keywords: Appendicitis; Computed tomography; Diagnostic algorithm; Magnetic resonance imaging; Ultrasound