title: Volume-dependent overestimation of spontaneous intracerebral hematoma volume by the ABC/2 formula.
abstract: BACKGROUND
  Although the ABC/2 formula has been widely used to estimate the volume of intracerebral hematoma (ICH), the formula tends to overestimate hematoma volume. The volume-related imprecision of the ABC/2 formula has not been documented quantitatively.
  
  
  OBJECTIVE
  To investigate the volume-dependent overestimation of the ABC/2 formula by comparing it with computer-assisted volumetric analysis (CAVA).
  
  
  METHODS
  Forty patients who had suffered spontaneous ICH and who had undergone non-enhanced brain computed tomography scans were enrolled in this study. The ICH volume was estimated based on the ABC/2 formula and also calculated by CAVA. Based on the ICH volume calculated by the CAVA method, the patients were divided into three groups: group 1 consisted of 17 patients with an ICH volume of less than 20 ml; group 2 comprised 13 patients with an ICH volume of 20 to 40 ml; and group 3 was composed of 10 patients with an ICH volume larger than 40 ml.
  
  
  RESULTS
  The mean estimated hematoma volume was 43.6 ml when using the ABC/2 formula, compared with 33.8 ml when using the CAVA method. The mean estimated difference was 1.3 ml, 4.4 ml, and 31.4 ml for groups 1, 2, and 3, respectively, corresponding to an estimation error of 9.9%, 16.7%, and 37.1% by the ABC/2 formula (P<0.05).
  
  
  CONCLUSIONS
  The ABC/2 formula significantly overestimates the volume of ICH. A positive association between the estimation error and the volume of ICH is demonstrated.
authors.affiliation: Department of Radiology, Tri-Service General Hospital, Taipei, Taiwan, ROC.
authors.forename: Chih-Wei
authors.initials: CW
authors.lastname: Wang
authors.forename: Chun-Jung
authors.initials: CJ
authors.lastname: Juan
authors.forename: Yi-Jui
authors.initials: YJ
authors.lastname: Liu
authors.forename: Hsian-He
authors.initials: HH
authors.lastname: Hsu
authors.forename: Hua-Shan
authors.initials: HS
authors.lastname: Liu
authors.forename: Cheng-Yu
authors.initials: CY
authors.lastname: Chen
authors.forename: Chun-Jen
authors.initials: CJ
authors.lastname: Hsueh
authors.forename: Chung-Ping
authors.initials: CP
authors.lastname: Lo
authors.forename: Hung-Wen
authors.initials: HW
authors.lastname: Kao
authors.forename: Guo-Shu
authors.initials: GS
authors.lastname: Huang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002543:Cerebral Hemorrhage / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000706:statistics & numerical data*; D016014:Linear Models; D008297:Male; D008432:Mathematical Computing; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012984:Software; D054894:Spiral Cone-Beam Computed Tomography / Q000706:statistics & numerical data*