ABC/2: Estimating intracerebral haemorrhage volume and total brain volume, and predicting outcome in children

Aim Few data exist to aid the clinician in prognosis after paediatric intracerebral haemorrhages (ICHs). Recently, ICH volume as a per cent of total brain volume (TBV) was shown to help predict outcomes in children. Thus, we sought to develop a bedside method of TBV estimation using typical hospital imaging software, and to validate the ABC/2 method for children in order to determine ICH volume and aid prognosis. Method The study group comprised 23 children and adolescents with non-traumatic, acute ICH who had undergone head computed tomography and who were available for analysis. The median age of participants, 14 males (61%) and nine females (39%), was 6years (range 0-16y; mean 7.8y; SD 5.3y). Preterm infants born at less than 37weeks' gestation and term infants with pure intraventricular haemorrhages were excluded. Manual segmentation, which is the criterion standard for measurement of ICH volume and TBV, requires specialized software and is time-consuming. We therefore used the well-known 'ABC/2×slice thickness' method to calculate ICH volume and TBV, thus allowing ICH size to be reported as a percentage of TBV regardless of the absolute size of ICH. Results The estimated ICH volume was highly accurate compared with the criterion standard (R²=0.97 and R²=0.93; combined R²=0.96), as was the estimated TBV (R²=0.89 and R²=0.77; combined R²=0.89). The interrater reliability was high for both ICH volume and TBV, with an intraclass correlation coefficient of 0.94 and 0.80 respectively. Therefore, using no specialized software, we accurately measured ICH volume as a percentage of TBV. Interpretation The ABC/2× slice thickness method is a possible bedside tool for the clinician that can aid prognosis after paediatric ICH.