Comparison of ABC / 2 with the Simplified ABC / 2 Formula in Calculating Intracerebral Hemorrhage Volume

Background: Bedside ABC/2 methods of measuring intracerebral hemorrhage (ICH) volumes are valuable clinical and research tools. The two most common methods of bedside calculation are the ABC/2 formula and the sABC/2 formula. Methods: We retrospectively reviewed 142 consecutive spontaneous ICH patients admitted to our institution from November 1, 2009 to October 1, 2010. ICH volume was calculated using both ABC/2 and sABC/2 methods. Based on the ICH volume calculated by the ABC/2 formula, the patients were divided into 3 groups: small (< 30cc), medium (30-60cc) and large (> 60cc). Results: Among 142 patients with ICH, the location was deep in 68 (47.8%), lobar in 52 (36.6%), and infratentorial in 22 (15.4%). The mean volume of ICH using ABC/2 was 17.5 cc (range, 0.19 to 90.3) and using sABC/2 was 30.4 cc (range, 0.26 to 171). The mean difference in volumes between ABC/2 and sABC/2 was 12.8 cc (SD + 17.6). The mean percentage difference in volumes between ABC/2 and sABC/2 was 76.9% (SD + 39.7). The differences between the volume by sABC/2 and ABC/2 increased with larger ICH volumes, with the equation of the regression line as follows: sABC2 = 0.2959659 + 1.7190626 ABC2 (p < 0.0001). Conclusion: sABC/2 and ABC2 methods do not correlate, and the differences between the methods increase with larger ICH volumes. Clinicians should be aware of the limitations of bedside ICH volume measurement tools.