title: Risk of pulmonary embolism after negative MDCT pulmonary angiography findings.
abstract: OBJECTIVE
  The purpose of our study was to determine the risk of pulmonary embolism in patients who have negative MDCT pulmonary angiography findings.
  
  
  METHODS
  In this prospective study, one hundred two consecutive patients with suspected pulmonary embolism underwent MDCT pulmonary angiography. Scans were reviewed jointly by two observers and findings recorded by consensus. Observers noted whether pulmonary embolism or other disease was present. No pulmonary embolism was seen in 85 patients (52 men and 33 women; age range, 20-94 years; mean age, 60 years) who were followed up for a mean of 9 months (range, 4-13 months) for evidence of subsequent pulmonary embolism.
  
  
  RESULTS
  One patient had a diagnosis of pulmonary embolism made within 3 weeks of undergoing CT pulmonary angiography. MDCT pulmonary angiography showed additional potentially significant findings in 76% of patients; 47% of these findings were not suspected on chest radiography.
  
  
  CONCLUSIONS
  The risk of pulmonary embolism at a mean of 9 months after negative MDCT pulmonary angiography findings is 1%. In our study of patients without pulmonary embolism, MDCT pulmonary angiography revealed other causes for individual patients' signs or symptoms in most cases.
authors.affiliation: Department of Radiology, Mater Misericordiae Hospital, Eccles St, Dublin 7, Ireland. eoinkav@yahoo.com
authors.forename: E C
authors.initials: EC
authors.lastname: Kavanagh
authors.forename: A
authors.initials: A
authors.lastname: O'Hare
authors.forename: G
authors.initials: G
authors.lastname: Hargaden
authors.forename: J G
authors.initials: JG
authors.lastname: Murray
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005188:False Negative Reactions; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000000981:diagnostic imaging*; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D018570:Risk Assessment; D014057:Tomography, X-Ray Computed / Q000379:methods; D014692:Ventilation-Perfusion Ratio