Effect of carotid artery stenting on cerebral blood flow: evaluation of hemodynamic changes using arterial spin labeling
The purpose of this work was to quantitatively evaluate the hemodynamic changes after carotid artery stenting (CAS) by measuring cerebral blood flow (CBF) using arterial spin labeling (ASL). Twenty sets of pre- and postprocedural CBF maps were acquired using ASL in patients who underwent CAS. Vascular territory- and anatomical structure-based regions of interest were applied to the CBF maps. Relative CBF (rCBF) was calculated by adjusting ipsilateral CBF with contralateral CBF. To assess the changes in rCBF after CAS (ΔrCBF), we calculated the following difference: $$ \Delta\mathrm{rCBF}=\mathrm{rCB}{{\mathrm{F}}_{\mathrm{postprocedural}}}-\mathrm{rCB}{{\mathrm{F}}_{\mathrm{preprocedural}}} $$ . Postprocedural CBFs were significantly higher than preprocedural CBFs for internal carotid artery and middle cerebral artery territories (P < 0.05 in both). Postprocedural rCBFs were also significantly higher than preprocedural rCBFs for internal carotid artery and middle cerebral artery territories (P < 0.05 in both). Significant correlations were observed between preprocedural rCBF and ΔrCBF for the internal carotid artery and middle cerebral artery territories (r = −0.7211, P = 0.0003 and r = −0.6427, P = 0.0022, respectively). Areas in which the ΔrCBF values were >5.00 ml 100 g−1 min−1 were the precentral, postcentral, middle frontal, middle temporal (caudal), superior parietal, and angular gyri. ASL has potential as a noninvasive imaging tool for the quantitative evaluation of hemodynamic changes after CAS. CAS improves cerebral perfusion in patients with carotid artery stenosis, and patients with greater perfusion deficits prior to CAS have greater improvement in perfusion after CAS. In addition, eloquent areas show the greatest improvement in perfusion.