Usefulness of the Arterial Spin-labeling Magnetic Resonance Imaging in Patients with Carotid Artery Stenosis Undergoing Carotid Endarterectomy

Once hyperperfusion occurs after carotid endarterectomy (CEA), artificial hypotension under sedation often needs to be induced until cerebral blood flow (CBF) improves. Arterial spin-labeling magnetic resonance imaging (ASL-MRI) can noninvasively evaluate cerebral blood perfusion. We investigated the usefulness of ASL-MRI in a series of patients with carotid artery stenosis who underwent CEA. We reviewed eight cases of carotid artery stenosis treated with CEA. In the preoperative examination, ASL-CBF had no correlation with the single-photon emission computed tomography (SPECT) -CBF finding (r = 0.03, p = 0.77). However, the ratio of the affected side to the healthy side on ASL-MRI had a significant positive linear correlation with that on SPECT (r = 0.74, p < 0.001). In two patients with hyperperfusion, ASL-MRI detected the hyperperfusion and serially tracked its improvement. Although ASL-CBF was less quantitative than the reference CBF value, it is a useful and noninvasive method to serially evaluate cerebral hemodynamics after CEA.