title: CT pulmonary angiography: quantification of pulmonary embolus as a predictor of patient outcome--initial experience.
abstract: OBJECTIVE
  To determine whether quantification of pulmonary embolus (PE) with computed tomographic (CT) pulmonary angiography by using a standardized index is a predictor of patient outcome.
  
  
  METHODS
  Multi-detector row CT was performed in 59 hospitalized patients (mean age, 61 years; age range, 22-89 years). PE was identified retrospectively by two radiologists who were blinded to patient outcome. A pulmonary arterial obstruction index was derived for each set of images on the basis of embolus size and location. By using logistic regression, PE indexes were compared with patient outcome-survival or death-to determine if there was a correlation between PE volume and survival.
  
  
  RESULTS
  The PE index is a significant predictor of patient outcome (P =.002). One of 53 patients (1.9%) with an index of less than 60% died. Cause of death was end-stage malignancy. Five of six patients (83%) with an index of 60% and higher died. All five deaths were related to the presence of PE. The one survivor with a PE index higher than 60% received thrombolytic therapy. By using a cutoff of 60%, the PE index was used to identify 52 of 53 (98%) patients who survived and five of six (83%) patients who died.
  
  
  CONCLUSIONS
  Preliminary evidence suggests that quantification of clot with CT pulmonary angiography is an important predictor of patient death in the setting of PE.
authors.affiliation: Department of Diagnostic Imaging, Rhode Island Hospital, Brown Medical School, 593 Eddy St, Main 3, Providence, RI 02903, USA.
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Wu
authors.forename: John A
authors.initials: JA
authors.lastname: Pezzullo
authors.forename: John J
authors.initials: JJ
authors.lastname: Cronan
authors.forename: David D
authors.initials: DD
authors.lastname: Hou
authors.forename: William W
authors.initials: WW
authors.lastname: Mayo-Smith
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011651:Pulmonary Artery / Q000000981:diagnostic imaging; D011655:Pulmonary Embolism / Q000145:classification / Q000000981:diagnostic imaging* / Q000401:mortality; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D015996:Survival Rate; D036542:Tomography, Spiral Computed; D016896:Treatment Outcome