Usefulness of three-dimensional computed tomography to quantify the subarachnoid hemorrhage volume: prediction of...

We quantified the subarachnoid hemorrhage (SAH) volume in 64 patients on three-dimensional computed tomography (3D-CT) scans and studied the correlation between the SAH volume and the occurrence of symptomatic vasospasm (SVS). We studied 64 patients with SAH onset (day 0) and on days 1, 4, 7, and 14. We compared the hematoma volume by 3D-CT with 2D-CT on day 0 and examined the correlation between the hematoma volume and the occurrence of SVS. The hematoma volume, including the volume of normal structures, was automatically calculated (V1). The volume of normal structures manifesting identical CT numbers was previously calculated in patients without intracranial lesions (V2). The total hematoma volume was defined as V1 minus mean value of V2 (= 12 ml). The mean hematoma volume by 3D-CT was 48 ± 12 ml and by 2D-CT was 31 ± 45 ml (mean ± SD, n = 64). The hematoma volume was significantly larger by 3D-CT than by 2D-CT (p < 0.05). At all time points, the hematoma volumes were significantly larger in patients with than without SVS. We developed a new method for the quantitative determination of the SAH volume by 3D-CT. This method may allow us to quantify the volume of SAH in clinical studies of cerebral vasospasm.