Comparison of ABC/2 Estimation Technique to Computer-Assisted Planimetric Analysis in Warfarin-Related Intracerebral Parenchymal Hemorrhage

Abstract

Background and Purpose-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 40.83Ϯ3.9 cm 3 (ABC/2) versus 36.6Ϯ3.5 cm 3 (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 ϩ32.1% (round shapes by ϩ6.7%; irregular shapes by ϩ14.9%; P ANOVA Ͻ0.01). 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 Ϫ10.3% in irregular and ϩ5.6% in separately shaped hematomas. Conclusions-In patients with OAT-related ICH, Ͼ50% 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. (Stroke. 2006;37:404-408.)

Reliability of the Size Evaluation Method for Meningiomas: Maximum Diameter, ABC/2 Formula, and Planimetry Method

“…Because the ABC/2 formula can provide the volume of a lesion easily and within short time, it is useful in clinical practice for cerebrovascular disorders, such as ICH (20)(21)(22)(23)(24)29) or cerebral infarction (30), that require rapid decision-making. However, the accuracy of the ABC/2 formula has been previously debated in these fields, particularly in ICH.…”

“…However, the accuracy of the ABC/2 formula has been previously debated in these fields, particularly in ICH. This is because the ABC/2 formula tends to overestimate volume if the hematoma is of an irregular shape (21,24,29). Because the ABC/2 formula is calculated on the presumption that the lesion is ellipsoid in shape, the calculated volume tends to differ from the exact volume if the form of the lesion differs from ellipsoid.…”

“…It is the simplest procedure; however, it is uncertain whether the maximum diameter accurately reflects the real volume of the tumor. The ABC/2 formula is frequently used to calculate the volume of intracerebral hemorrhage (ICH) because of its simplicity and quickness; however, the accuracy of the ABC/2 formula has been previously debated (20)(21)(22)(23)(24). Although some studies have used the ABC/2 formula (2,25,26) or the original ellipsoid volume (10,19,27) to measure the volume of intracranial tumors, including meningiomas, few studies have evaluated the accuracy of ABC/2 formula for intracranial tumors.…”

Serum Magnesium Levels and Outcomes in Patients With Acute Spontaneous Intracerebral Hemorrhage

“…We believe that hemostatic treatment would be a major confounding factor while evaluating the potential hemostatic property of Mg in patients with ICH. Seventh, the ABC/2 score accurately estimates hematoma volume in cases of round‐to‐ellipsoid shape of the hematoma and overestimates volume in irregular and separated shapes 29. However, separated and irregular hematoma shapes occur more frequently in oral anticoagulation therapy–related ICHs,29 and we did not include ICH caused by coagulopathy in our cohort.…”

“…Seventh, the ABC/2 score accurately estimates hematoma volume in cases of round‐to‐ellipsoid shape of the hematoma and overestimates volume in irregular and separated shapes 29. However, separated and irregular hematoma shapes occur more frequently in oral anticoagulation therapy–related ICHs,29 and we did not include ICH caused by coagulopathy in our cohort. Eighth, we included patients with acute ICH presenting within 24 hours of symptom onset in our study.…”