title: Axial and reformatted four-chamber right ventricle-to-left ventricle diameter ratios on pulmonary CT angiography as predictors of death after acute pulmonary embolism.
abstract: OBJECTIVE
  The purpose of this article is to retrospectively compare right ventricular-to-left ventricular (RV/LV) diameter ratios measured on the standard axial view versus the reformatted four-chamber view as predictors of mortality after acute pulmonary embolism (PE).
  
  
  METHODS
  Six hundred seventy-four consecutive patients (mean age, 58 years; 372 women) with a diagnosis of acute PE on pulmonary CT angiography were considered. The axial and reformatted four-chamber RV/LV diameter ratios were compared as predictors of 30-day all-cause and PE-related mortality.
  
  
  RESULTS
  Ninety-seven patients (14%) died within 30 days; 39 deaths were PE related. There was no significant difference in the univariate hazard ratios (HRs) of axial and four-chamber RV/LV diameter ratios greater than 0.9 for both all-cause (HR, 2.13 [95% CI, 1.29-3.51] vs HR, 1.95 [95% CI, 1.22-3.14]; p = 0.74) and PE-related (HR, 19.6 [95% CI, 2.70-143] vs HR, 21.8 [95% CI, 2.99-158]; p = 1.0) mortality. Axial and four-chamber multivariate HRs accounting for potential confounders such as age and cancer were also similar for all-cause (HR, 1.79 [95% CI, 1.07-2.99] vs HR, 1.54 [95% CI, 0.95-2.49]; p = 0.62) and PE-related (HR, 16.3 [95% CI, 2.22-119] vs HR, 17.7 [95% CI, 2.43-130]; p = 1.0) mortality. There was no significant difference in sensitivity, specificity, negative predictive value, or positive predictive value. Axial and four-chamber measurements were well correlated (correlation coefficient, 0.857), and there was no significant difference in overall accuracy for predicting all-cause (area under the curve [AUC], 0.582 vs 0.577; p = 0.72) and PE-related (AUC, 0.743 vs 0.744; p = 1.0) mortality.
  
  
  CONCLUSIONS
  The axial RV/LV diameter ratio is no less accurate than the reformatted four-chamber RV/LV diameter ratio for predicting 30-day mortality after PE.
authors.affiliation: Applied Imaging Science Laboratory, Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Lu
authors.forename: Shadpour
authors.initials: S
authors.lastname: Demehri
authors.forename: Tianxi
authors.initials: T
authors.lastname: Cai
authors.forename: Layla
authors.initials: L
authors.lastname: Parast
authors.forename: Andetta R
authors.initials: AR
authors.lastname: Hunsaker
authors.forename: Samuel Z
authors.initials: SZ
authors.lastname: Goldhaber
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Rybicki
mesh_terms: D000792:Angiography / Q000379:methods*; D015897:Comorbidity; D003287:Contrast Media; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging* / Q000401:mortality*; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D015996:Survival Rate; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media