Background and Aims Carotid stenosis is an important cause of stroke, especially ischemic stroke. Early detection and effective treatment are essential for reducing the occurrence of ischemic stroke. Carotid artery stenting (CAS) is a common modality for the treatment of carotid artery stenosis, but various complications may occur during and after this procedure, and there is still the risk of restenosis or occlusion, thus evaluating its efficacy through effective methods is of important clinical significance. This study was conducted to analyzed the assessing abilities of computed tomography perfusion (CTP) and high-resolution magnetic resonance imaging (HR-MRI) in patients with carotid stenosis after CAS.Methods The data of 44 patients with carotid artery stenosis who underwent CAS treatment between February 2017 and February 2020 were collected. All the included patients underwent CTP, HR-MRI and DSA examinations before and 2 months after CAS. The differences in the parameters of CTP and HR-MRI before and after CAS were compared, and using the results of DSA as a gold standard, the relative efficiency of the two methods in detecting residual carotid artery stenosis was compared.Results The results of CTP showed that the relative cerebral blood flow of cerebral artery was increased and the relative transit time and relative time to peak were decreased significantly (all P<0.05), while no significant difference was noted in the relative cerebral blood volume on 2 months after operation compared with their values before operation (P>0.05). The results of HR-MRI showed that there were no significant differences in the vascular area, tube wall area and lumen area (all P>0.05), and the plaque area and plaque load were significantly reduced on 2 months after operation compared with their values before operation (both P<0.05). DSA detected 16 branches of carotid arteries with stenosis, and the improvement rate of carotid artery stenosis was 80.00%, CTP detected 12 branches of carotid arteries with stenosis, and the improvement rate of carotid artery stenosis was 85.00%, and HR-MRI detected 14 branches of carotid arteries with stenosis, and the improvement rate of carotid artery stenosis was 82.50%. The two methods had a similar ability in detecting the residual carotid artery stenosis (P>0.05).Conclusion Both CTP and HR-MRI can be used to evaluate the efficacy of CAS in patients with carotid stenosis. The complementary use of the two methods has certain clinical application value.