title: Evaluation of spiral computed tomography versus ventilation/perfusion scanning in patients clinically suspected of pulmonary embolism.
abstract: OBJECTIVE
  To prospectively evaluate the diagnostic accuracy of spiral computed tomography (CT) versus ventilation/perfusion (V/Q) scanning in the examination of patients clinically suspected of having pulmonary embolism (PE).
  
  
  METHODS
  Sixty-three patients, presenting to the emergency department and departments of radiology and nuclear medicine of a large hospital, highly suspected of having PE, underwent sequential imaging testing with V/Q scanning and contrast-enhanced spiral CT, in addition to other clinical and laboratory tests.
  
  
  RESULTS
  PE was diagnosed in 42 (66.7%) of the 63 patients. Thirty-nine of these 42 patients had positive findings in their CT scans, while 18 of the remaining 21 patients without PE had negative findings in their spiral CT [sensitivity, 92.9%, specificity, 85.7% Positive Predictive Value (PPV), 92.9%, Negative Predictive Value (NPV), 85.7%]. V/Q scans showed high-probability of PE in 24 of the 42 patients with PE and were negative in 9 of the remaining 21 patients without PE (sensitivity, 571%, specificity, 42.9%, PPV, 66.7%, NPV, 33.3%). There were statistically significant differences in specificity and sensitivity favoring spiral CT among men and women patients or patients > 50 years old. Fifty-four patients (85.7%) rated their satisfaction towards spiral CT as 'good' or 'very good', whereas the respective rate for V/Q scanning was only 14.3%.
  
  
  CONCLUSIONS
  Spiral CT has an excellent sensitivity, specificity, PPV and NPV for the diagnosis of PE and it could be used as the first-line imaging modality in patients suspected of PE.
authors.affiliation: Pain Relief and Palliative Care Unit, Department of Radiology, Areteion Hospital, School of Medicine, University of Athens, 27 Korinthias Str., 115 26 Athens, Greece.
authors.forename: Emmanouela
authors.initials: E
authors.lastname: Katsouda
authors.forename: Kyriaki
authors.initials: K
authors.lastname: Mystakidou
authors.forename: Aggeliki
authors.initials: A
authors.lastname: Rapti
authors.forename: Stelios
authors.initials: S
authors.lastname: Argentos
authors.forename: Nikolaos L
authors.initials: NL
authors.lastname: Kelekis
authors.forename: Renata
authors.initials: R
authors.lastname: Mastorakou
authors.forename: Ourania
authors.initials: O
authors.lastname: Anagnostopoulou
authors.forename: Dimitrios A
authors.initials: DA
authors.lastname: Kelekis
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004198:Disease Susceptibility; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011655:Pulmonary Embolism / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014692:Ventilation-Perfusion Ratio