title: Multidetector computed tomographic pulmonary angiography in patients with a high clinical probability of pulmonary embolism.
abstract: ESSENTIALS: When high probability of pulmonary embolism (PE), sensitivity of computed tomography (CT) is unclear. We investigated the sensitivity of multidetector CT among 134 patients with a high probability of PE. A normal CT alone may not safely exclude PE in patients with a high clinical pretest probability. In patients with no clear alternative diagnosis after CTPA, further testing should be strongly considered.
  
  
  BACKGROUND
  Whether patients with a negative multidetector computed tomographic pulmonary angiography (CTPA) result and a high clinical pretest probability of pulmonary embolism (PE) should be further investigated is controversial.
  
  
  METHODS
  This was a prospective investigation of the sensitivity of multidetector CTPA among patients with a priori clinical assessment of a high probability of PE according to the Wells criteria. Among patients with a negative CTPA result, the diagnosis of PE required at least one of the following conditions: ventilation/perfusion lung scan showing a high probability of PE in a patient with no history of PE, abnormal findings on venous ultrasonography in a patient without previous deep vein thrombosis at that site, or the occurrence of venous thromboembolism (VTE) in a 3-month follow-up period after anticoagulation was withheld because of a negative multidetector CTPA result.
  
  
  RESULTS
  We identified 498 patients with a priori clinical assessment of a high probability of PE and a completed CTPA study. CTPA excluded PE in 134 patients; in these patients, the pooled incidence of VTE was 5.2% (seven of 134 patients; 95% confidence interval [CI] 1.5-9.0). Five patients had VTEs that were confirmed by an additional imaging test despite a negative CTPA result (five of 48 patients; 10.4%; 95% CI 1.8-19.1), and two patients had objectively confirmed VTEs that occurred during clinical follow-up of at least 3 months (two of 86 patients; 2.3%; 95% CI 0-5.5). None of the patients had a fatal PE during follow-up.
  
  
  CONCLUSIONS
  A normal multidetector CTPA result alone may not safely exclude PE in patients with a high clinical pretest probability.
authors.affiliation: F. Edward Hebert School of Medicine, Uniformed Services University, Bethesda, MD, USA.
authors.forename: L
authors.initials: L
authors.lastname: Moores
authors.affiliation: Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: J
authors.initials: J
authors.lastname: Kline
authors.affiliation: Department of Internal Medicine, Instituto Ramon y Cajal de Investigacion Sanitaria IRYCIS, Ramón y Cajal Hospital, Madrid, Spain.
authors.forename: A K
authors.initials: AK
authors.lastname: Portillo
authors.affiliation: Radiology Department, Instituto Ramón y Cajal de Investigación Sanitaria IRYCIS, Ramón y Cajal Hospital, Madrid, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Resano
authors.affiliation: Radiology Department, Instituto Ramón y Cajal de Investigación Sanitaria IRYCIS, Ramón y Cajal Hospital, Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Vicente
authors.affiliation: Respiratory Department, Instituto Ramón y Cajal de Investigación Sanitaria IRYCIS, Ramón y Cajal Hospital, Alcala de Henares University, Madrid, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Arrieta
authors.affiliation: Emergency Department, Instituto Ramón y Cajal de Investigación Sanitaria IRYCIS, Ramón y Cajal Hospital, Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Corres
authors.affiliation: Divisions of Pulmonary and Critical Care Medicine, Cedars-Sinai, Los Angeles, CA, USA.
authors.forename: V
authors.initials: V
authors.lastname: Tapson
authors.affiliation: Divisions of Pulmonary and Critical Care Medicine and General Medical Sciences, Washington University School of Medicine, St Louis, MO, USA.
authors.forename: R D
authors.initials: RD
authors.lastname: Yusen
authors.affiliation: Respiratory Department, Instituto Ramón y Cajal de Investigación Sanitaria IRYCIS, Ramón y Cajal Hospital, Alcala de Henares University, Madrid, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Jiménez
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods*; D000925:Anticoagulants / Q000737:chemistry; D003657:Decision Making; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D005500:Follow-Up Studies; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D011336:Probability; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging* / Q000453:epidemiology; D013030:Spain; D054556:Venous Thromboembolism / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000453:epidemiology; D020246:Venous Thrombosis / Q000175:diagnosis; D055815:Young Adult
chemical_list: D000925:Anticoagulants; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D
keywords: diagnosis; diagnostic imaging; multidetector computed tomography; probability; pulmonary embolism