title: A new formula for rapid assessment of pericardial effusion volume by computed tomography.
abstract: OBJECTIVE
  The aim of this study was to evaluate a new formula for the rapid assessment of pericardial effusion (PE) volume by computed tomography.
  
  
  METHODS
  Twenty computed tomographic scans positive for PE were reviewed by two observers. Diameters of PE were measured at four locations. Additionally, PE volume was assessed by volumetry. The correlation between PE diameters and volume was evaluated, and a linear equation was derived for each diameter location. To test validity and reliability of the measurements, intraclass correlation and Bland-Altman analysis were performed.
  
  
  RESULTS
  Good validity was expressed by strong correlations between diameter measurements at all four locations and PE volume (all R values >0.80 and P values <.0001). Intraclass correlation (all coefficients >0.75) and Bland-Altman analysis revealed good interobserver and intraobserver reliability of diameter measurements. The best values were observed for apical diameter measurements. The following linear equation was derived for apical diameter measurements: PE volume = 296 (mL/cm) × apical diameter (cm) - 32 mL.
  
  
  CONCLUSIONS
  PE volume can rapidly be assessed by apical PE diameter measurement using the simplified formula PE volume = 0.3 (L/cm) × apical diameter (cm).
authors.affiliation: Center for Radiology and Endoscopy, Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany. groth.michael@googlemail.com
authors.forename: Michael
authors.initials: M
authors.lastname: Groth
authors.forename: Marc
authors.initials: M
authors.lastname: Regier
authors.forename: Kai
authors.initials: K
authors.lastname: Muellerleile
authors.forename: Peter
authors.initials: P
authors.lastname: Bannas
authors.forename: Gerhard
authors.initials: G
authors.lastname: Adam
authors.forename: Frank Oliver
authors.initials: FO
authors.lastname: Henes
mesh_terms: D000465:Algorithms; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010490:Pericardial Effusion / Q000000981:diagnostic imaging*; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*