title: Comparison of ABC/2 estimation technique to computer-assisted planimetric analysis in warfarin-related intracerebral parenchymal hemorrhage.
abstract: OBJECTIVE
  The ABC/2 formula is a reliable estimation technique of intracerebral hematoma volume. However, oral anticoagulant therapy (OAT)-related intracerebral hemorrhage (ICH) compared with primary ICH is based on a different pathophysiological mechanism, and various shapes of hematomas are more likely to occur. Our objective was to validate the ABC/2 technique based on analyses of the hematoma shapes in OAT-related ICH.
  
  
  METHODS
  We reviewed the computed tomography scans of 83 patients with OAT-associated intraparenchymal ICH. Location was divided into deep, lobar, cerebellar, and brain stem hemorrhage. Shape of the ICH was divided into (A) round-to-ellipsoid, (B) irregular with frayed margins, and (C) multinodular to separated. The ABC/2 technique was compared with computer-assisted planimetric analyses with regard to hematoma site and shape.
  
  
  RESULTS
  The mean hematoma volume was 40.83+/-3.9 cm3 (ABC/2) versus 36.6+/-3.5 cm3 (planimetric analysis). Bland-Altman plots suggested equivalence of both estimation techniques, especially for smaller ICH volumes. The most frequent location was a deep hemorrhage (54%), followed by lobar (21%), cerebellar (14%) and brain stem hemorrhage (11%). The most common shape was round-to-ellipsoid (44%), followed by irregular ICH (31%) and separated and multinodular shapes (25%). In the latter, ABC/2 formula significantly overestimated volume by +32.1% (round shapes by +6.7%; irregular shapes by +14.9%; P ANOVA <0.01). Variation of the denominator toward ABC/3 in cases of irregularly and separately shaped hematomas revealed more a precise volume estimation with a deviation of -10.3% in irregular and +5.6% in separately shaped hematomas.
  
  
  CONCLUSIONS
  In patients with OAT-related ICH, >50% of bleedings are irregularly shaped. In these cases, hematoma volume is significantly overestimated by the ABC/2 formula. Modification of the denominator to 3 (ie, ABC/3) measured ICH volume more accurately in these patients potentially facilitating treatment decisions.
authors.affiliation: Department of Neurology, University of Heidelberg, Heidelberg, Germany. hagen.huttner@med.uni-heidelberg.de
authors.forename: Hagen B
authors.initials: HB
authors.lastname: Huttner
authors.forename: Thorsten
authors.initials: T
authors.lastname: Steiner
authors.forename: Marius
authors.initials: M
authors.lastname: Hartmann
authors.forename: Martin
authors.initials: M
authors.lastname: Köhrmann
authors.forename: Eric
authors.initials: E
authors.lastname: Juettler
authors.forename: Stephan
authors.initials: S
authors.lastname: Mueller
authors.forename: Johannes
authors.initials: J
authors.lastname: Wikner
authors.forename: Uta
authors.initials: U
authors.lastname: Meyding-Lamade
authors.forename: Peter
authors.initials: P
authors.lastname: Schramm
authors.forename: Stefan
authors.initials: S
authors.lastname: Schwab
authors.forename: Peter D
authors.initials: PD
authors.lastname: Schellinger
mesh_terms: D000465:Algorithms; D001921:Brain / Q000473:pathology; D002543:Cerebral Hemorrhage / Q000139:chemically induced* / Q000175:diagnosis* / Q000473:pathology; D006408:Hematoma, Subdural / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D015233:Models, Statistical; D011379:Prognosis; D011446:Prospective Studies; D012984:Software; D020521:Stroke / Q000139:chemically induced / Q000175:diagnosis; D015912:Thrombolytic Therapy / Q000009:adverse effects; D014057:Tomography, X-Ray Computed; D014859:Warfarin / Q000494:pharmacology*
chemical_list: D014859:Warfarin