Perfusion CT investigation of chronic internal carotid artery occlusion: comparison with SPECT

This study investigated the usefulness of perfusion computed tomography (CT) for the evaluation of patients with chronic internal carotid artery (ICA) occlusion by comparing the findings with those of iodine-123 iodoamphetamine ([123I]IMP) single photon emission computed tomography (SPECT). Twenty five patients with chronic ICA occlusion were investigated on the same day by perfusion CT to measure the cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transient time (MTT), and [123I]IMP SPECT to measure the regional CBF, significant correlations were observed between regional CBF measured by SPECT and CBF measured by perfusion CT (r = 0.659, R2 = 0.434, p < 0.001), regional CBF and CBV (r = −0.406, R2 = 0.165, p < 0.001) and regional CBF and MTT (r = −0.592, R2 = 0.350, p < 0.001). Significant correlations were also observed between CBF and CBV (r = −0.153, R2 = 0.023, p < 0.001), CBF and MTT (r = −0.580, R2 = 0.337, p < 0.001) and MTT and CBV (r = 0.763, R2 = 0.582, p < 0.001). Perfusion CT is useful to evaluate the hemodynamic state of patients with chronic major cerebral artery occlusive disorders.