title: Diagnostic accuracy of lung ultrasound for pulmonary embolism: a systematic review and meta-analysis.
abstract: BACKGROUND
  Computed tomographic pulmonary angiography (CTPA) has simplified the diagnostic approach to patients with suspected pulmonary embolism (PE). However, PE diagnosis is still probabilistic and CTPA should be used with caution in some patient groups, such as patients with severe renal insufficiency and pregnant women. Among alternative imaging tests, lung ultrasound is the most promising technique. We aimed to systematically assess the diagnostic accuracy of lung ultrasound for PE diagnosis.
  
  
  METHODS
  Studies evaluating the diagnostic accuracy of lung ultrasound for the diagnosis of PE were systematically searched for in the MEDLINE and EMBASE databases (up to June 2012). The QUADAS-2 tool was used for the quality assessment of the primary studies. A bivariate random-effects regression approach was used for summary estimates of both sensitivity and specificity.
  
  
  RESULTS
  Ten studies, for a total of 887 patients, were included. A composite reference test was used in six studies, with single-row detector CTPA as the principal imaging test in four studies. Overall, seven studies used a proper reference test. Lung ultrasound bivariate weighted mean sensitivity was 87.0% (95% confidence interval [CI] 79.5, 92.0%), whereas bivariate weighted mean specificity was 81.8% (95% CI 71.0, 89.3%).
  
  
  CONCLUSIONS
  Our findings suggest that lung ultrasound may be a useful diagnostic tool in the management of patients with suspected PE. However, several methodological drawbacks of the primary studies limit any definite conclusion. Further well-designed accuracy studies are necessary before planning diagnostic management studies, in particular in those with a contraindication for CTPA.
authors.affiliation: Research Center on Thromboembolic Disorders and Antithrombotic Therapies, Department of Clinical and Experimental Medicine, University of Insubria, Viale Borri 57,Varese, Italy. alessandro.squizzato@uninsubria.it
authors.forename: A
authors.initials: A
authors.lastname: Squizzato
authors.forename: E
authors.initials: E
authors.lastname: Rancan
authors.forename: F
authors.initials: F
authors.lastname: Dentali
authors.forename: M
authors.initials: M
authors.lastname: Bonzini
authors.forename: L
authors.initials: L
authors.lastname: Guasti
authors.forename: L
authors.initials: L
authors.lastname: Steidl
authors.forename: G
authors.initials: G
authors.lastname: Mathis
authors.forename: W
authors.initials: W
authors.lastname: Ageno
mesh_terms: D006801:Humans; D016015:Logistic Models; D008168:Lung / Q000098:blood supply*; D011237:Predictive Value of Tests; D011379:Prognosis; D011651:Pulmonary Artery / Q000000981:diagnostic imaging*; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography
keywords: diagnosis; pulmonary embolism; spiral computed; throax ultrasonagraphy; tomography; ultrasonography