title: The preliminary exploration of 64-slice volume computed tomography in the accurate measurement of pleural effusion.
abstract: BACKGROUND
  Using computed tomography (CT) to rapidly and accurately quantify pleural effusion volume benefits medical and scientific research. However, the precise volume of pleural effusions still involves many challenges and currently does not have a recognized accurate measuring.
  
  
  OBJECTIVE
  To explore the feasibility of using 64-slice CT volume-rendering technology to accurately measure pleural fluid volume and to then analyze the correlation between the volume of the free pleural effusion and the different diameters of the pleural effusion.
  
  
  METHODS
  The 64-slice CT volume-rendering technique was used to measure and analyze three parts. First, the fluid volume of a self-made thoracic model was measured and compared with the actual injected volume. Second, the pleural effusion volume was measured before and after pleural fluid drainage in 25 patients, and the volume reduction was compared with the actual volume of the liquid extract. Finally, the free pleural effusion volume was measured in 26 patients to analyze the correlation between it and the diameter of the effusion, which was then used to calculate the regression equation.
  
  
  RESULTS
  After using the 64-slice CT volume-rendering technique to measure the fluid volume of the self-made thoracic model, the results were compared with the actual injection volume. No significant differences were found, P = 0.836. For the 25 patients with drained pleural effusions, the comparison of the reduction volume with the actual volume of the liquid extract revealed no significant differences, P = 0.989. The following linear regression equation was used to compare the pleural effusion volume (V) (measured by the CT volume-rendering technique) with the pleural effusion greatest depth (d): V = 158.16 × d - 116.01 (r = 0.91, P = 0.000). The following linear regression was used to compare the volume with the product of the pleural effusion diameters (l × h × d): V = 0.56 × (l × h × d) + 39.44 (r = 0.92, P = 0.000).
  
  
  CONCLUSIONS
  The 64-slice CT volume-rendering technique can accurately measure the volume in pleural effusion patients, and a linear regression equation can be used to estimate the volume of the free pleural effusion.
authors.affiliation: Department of Radiology.
authors.forename: Zhi-Jun
authors.initials: ZJ
authors.lastname: Guo
authors.forename: Qiang
authors.initials: Q
authors.lastname: Lin
authors.forename: Hai-Tao
authors.initials: HT
authors.lastname: Liu
authors.forename: Jun-Ying
authors.initials: JY
authors.lastname: Lu
authors.forename: Yan-Hong
authors.initials: YH
authors.lastname: Zeng
authors.forename: Fan-Jie
authors.initials: FJ
authors.lastname: Meng
authors.forename: Bin
authors.initials: B
authors.lastname: Cao
authors.forename: Xue-Rong
authors.initials: XR
authors.lastname: Zi
authors.forename: Shu-Ming
authors.initials: SM
authors.lastname: Han
authors.forename: Yu-Huan
authors.initials: YH
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D003937:Diagnosis, Differential; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010996:Pleural Effusion / Q000000981:diagnostic imaging*
keywords: Tomography; X-ray computed; pleural effusion; volume measurement; volume rendering