Density of the cerebral cortex in computed tomography angiography source images and clinical outcomes in Grade V subarachnoid hemorrhage

Objective: Among patients diagnosed with Grade V subarachnoid hemorrhage (SAH) according to the World Federation of Neurosurgical Societies (WFNS), the identification of those with the possibility of recovery is not feasible, although approximately one-fifth of these patients have favorable outcomes according to a recently published series of surgical papers. We hypothesized that computed tomography angiography (CTA) source images (SIs), which have applied to the detection of acute ischemia, might be useful for selecting Grade V patients with possibilities for favorable outcomes. Methods: We retrospectively assessed 170 SAH patients who underwent surgery between January 2009 and February 2012 and quantitatively measured their mean cerebral cortical densities from the initial CTA-SIs. Results: The cortical densities of 123 patients of Grades I-IV were strongly affected by the following two CTA-SI findings that were revealed by multivariate analysis: the density of the internal carotid artery (ICA) just proximal to the petrous portion and the ratio of the subarachnoid (SA) space to intracranial volume (P < 0.05). Favorable outcomes were obtained in 9 of the 47 Grade V patients (19.1%), and the predictors of the favorable outcomes according to multivariate analysis were increased cortical densities on the CTA-SIs and female patients (P < 0.05). Conclusion: The outcomes of Grade V patients could be partly predicted based on the estimates of cortical density from the CTA-SIs, and this measure might be useful for the selection of Grade V patients for surgery, provided that both ICA density and SA space ratio are confirmed before the evaluation of cortical density.