title: Risk of pulmonary embolism after a negative spiral CT angiogram in patients with pulmonary disease: 1-year clinical follow-up study.
abstract: OBJECTIVE
  To evaluate the effect of pulmonary disease on diagnostic utility of spiral computed tomographic (CT) angiography in clinical practice.
  
  
  METHODS
  Three hundred thirty-four patients, including 215 patients with pulmonary disease (group 1) and 119 patients with no history of respiratory disorder (group 2), were referred for thin-collimation CT angiography of the pulmonary circulation as the first-line diagnostic test. Patients with negative angiograms who had not received anticoagulation therapy and who could be clinically followed up at 3 months, 6 months, and 1 year were considered in the final study groups (n = 185); 135 patients had lung disease (group 3), and 50 patients had no history of a respiratory disorder (group 4).
  
  
  RESULTS
  Between groups 3 and 4, no significant differences were found in the referral location, age, and risk factors. Confident evaluation of pulmonary arteries down to the subsegmental level was performed in 31 (23%) patients in group 3 and in 15 (30%) in group 4 (P =.5). Three episodes of acute pulmonary embolism (PE), all fatal, were diagnosed in group 3 patients; two cases occurred 14 days and one case occurred 6 months after the negative spiral CT scan. The negative predictive value of spiral CT angiography was 98% (175 of 178) in the study group in which follow-up was performed, with no significant difference between the values in groups 3 (98% [132 of 135]) and 4 (100% [50 of 50]).
  
  
  CONCLUSIONS
  Underlying respiratory disease does not affect the negative predictive value of thin-collimation CT angiography, which appears to be a reliable tool in the work-up in this subgroup of patients with acute PE.
authors: Department of Pulmonology, University Center Hospital Calmette, Lille, France.
authors: Isabelle
authors: I
authors: Tillie-Leblond
authors: Ioana
authors: I
authors: Mastora
authors: Fabienne
authors: F
authors: Radenne
authors: Sandrine
authors: S
authors: Paillard
authors: André-Bernard
authors: AB
authors: Tonnel
authors: Jacques
authors: J
authors: Remy
authors: Martine
authors: M
authors: Remy-Jardin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography; D016009:Chi-Square Distribution; D005188:False Negative Reactions; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008171:Lung Diseases / Q000150:complications* / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging* / Q000209:etiology*; D012307:Risk Factors; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods*