title: Is It possible to recognize pulmonary infarction on multisection CT images?
abstract: OBJECTIVE
  To retrospectively determine sensitivity and specificity of four findings for distinguishing pulmonary infarction from other causes of peripheral pulmonary consolidations on multidetector computed tomographic (CT) images, with other CT and clinical findings as reference.
  
  
  METHODS
  Institutional review board approved the study and waived informed consent. Three independent radiologists blindly analyzed selected multisection CT images of 50 pulmonary infarctions-not showing direct arterial signs of pulmonary embolism-and 100 peripheral consolidations of other origins. Readers analyzed four findings: triangular shape, vessel sign (defined as presence of an enlarged vessel at the apex of consolidation), central lucencies, and air bronchograms. Interobserver agreement; frequency on CT images with and without infarct; and sensitivity, specificity, and positive likelihood ratio (LR) for diagnosis of pulmonary infarction were assessed for each finding.
  
  
  RESULTS
  One hundred fifty peripheral consolidations were analyzed in 134 (75 men, 59 women) patients (mean age, 55.9 years+/-17.4 [standard deviation] vs 54.7+/-19.9; P=.71). Interobserver agreement was good for central lucencies and air bronchograms and poor to moderate for the other two findings (kappa<0.61). Compared with CT images without infarct, CT images with infarct had a higher frequency of vessel sign (32% [16 of 50] vs 11% [11 of 100], P=.029) and central lucencies (46% [23 of 50] vs 2% [two of 100], P<.001) and a lower frequency of air bronchograms (8% [four of 50] vs 40% [40 of 100], P=.003). Frequency of triangular shape was similar in both groups (52% [26 of 50] vs 40% [40 of 100], P=.17). Positive LR was 23.0 for central lucencies, 2.9 for vessel sign, 1.3 for triangular shape, and 0.2 for air bronchograms. Presence of central lucencies had 98% specificity and 46% sensitivity for pulmonary infarction. When the vessel sign and negative air bronchogram were combined with central lucencies, specificity increased to 99% but sensitivity decreased to 14%.
  
  
  CONCLUSIONS
  Central lucencies in peripheral consolidations are highly suggestive of pulmonary infarction.
authors: Assistance Publique des Hôpitaux de Paris, and Université Paris Descartes, France. marie-pierre.revel@egp.aphp.fr
authors: Marie-Pierre
authors: MP
authors: Revel
authors: Rached
authors: R
authors: Triki
authors: Gilles
authors: G
authors: Chatellier
authors: Sophie
authors: S
authors: Couchon
authors: Nathalie
authors: N
authors: Haddad
authors: Anne
authors: A
authors: Hernigou
authors: Claire
authors: C
authors: Danel
authors: Guy
authors: G
authors: Frija
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007238:Infarction / Q000000981:diagnostic imaging*; D008168:Lung / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed / Q000379:methods*
chemical_list: D003287:Contrast Media