Reliability of ABC/2 volumetric estimation in spontaneous intracerebral hemorrhage for hematoma expansion prediction scores.

Introduction: Prediction scores for hematoma expansion in spontaneous intracerebral hemorrhage (ICH), such as the 9-point and BRAIN scores, were developed predominantly using planimetry to measure hematoma volume. In this study, we aim to investigate whether the ABC/2 formula, which is known to overestimate hematoma volume, can be reliably used as a substitute for planimetry in these prediction scores.

Patients and methods: A total of 429 patients from four hospitals were retrospectively enrolled. CT scan and clinical data at admission and follow-up CT scan were collected. The 9-point and BRAIN scores were calculated using hematoma volume from ABC/2 and planimetry. Hematoma expansion was assessed using hematoma volume from planimetry.

Results: The median hematoma volume measured by ABC/2 was 11.97 ml (interquartile range [IQR], 4.8-30.0), whereas the volume measured by planimetry was 11.70 ml (IQR, 4.9-26.6). The median measurement error between ABC/2 and planimetry was 0.30 ml (IQR, -0.72-2.87). ABC/2 overestimated hematoma volume in 244 patients (56.9%) compared to planimetry. In the 9-point score, the area under the curves (AUCs) for predicting hematoma expansion were 0.735 (95% confidence interval [CI], 0.675-0.796) with ABC/2 and 0.732 (95% CI, 0.672-0.793) with planimetry. In the BRAIN score, the AUCs were 0.753 (95% CI, 0.693-0.813) with ABC/2 and 0.745 (95% CI, 0.688-0.803) with planimetry.

Discussion and conclusion: The 9-point and BRAIN scores using hematoma volume measured by ABC/2 and planimetry showed good performance in predicting hematoma expansion in ICH. ABC/2 volumetric estimation proved to be reliable for these scores.