Objective  To explore the value of easy Z-score imaging system (eZIS) in the evaluation of carotid endarterectomy (CEA) in the treatment of carotid artery stenosis and to analyze its consistency with magnetic resonance angiography (MRA).

Methods  The clinical data of 18 patients with carotid artery stenosis (unilateral or bilateral) who underwent ⁹⁹Tc^m-ethylcysteinate dimer cerebral blood flow perfusion SPECT/CT imaging and MRA examination at Tianjin Medical University General Hospital from June 2018 to January 2021 were retrospectively analyzed. Whether CEA was performed or not, the patients were divided into the surgical treatment group and non-surgical treatment group. The surgical treatment group consisted of 7 patients, including 5 males and 2 females, aged (58.4±7.6) years. All 7 patients underwent SPECT/CT imaging and MRA examination before and within 6 months after surgery. On the contrary, the non-surgical treatment group consisted of 11 patients, including 8 males and 3 females, aged (62.6±11.1) years. All 11 patients received routine drug treatment and underwent SPECT/CT imaging and MRA examination before and after treatment, all of which were completed within 6 months. The local cerebral blood flow at the lesion site of the patients was measured, and the changes in Z-score before and after treatment were calculated by using eZIS. A paired sample t-test was used to verify the change in Z-score and carotid artery stenosis degree in the two groups before and after treatment. The consistency of MRA and SPECT/CT eZIS results was analyzed by conducting the Kappa test.

Results  The postoperative Z-score (0.54±2.71) in the surgical treatment group was remarkably higher than that before surgery (−1.34±2.68), and the difference was statistically significant (t=3.899, P=0.008). The Z-score (−0.33±2.58) of patients in the non-surgical treatment group decreased remarkably after treatment compared with that before treatment (1.84±2.62), and the difference was statistically significant (t=4.618, P=0.001). The degree of carotid artery stenosis in the surgical treatment group was remarkably reduced after surgery compared with that before surgery, and the difference was statistically significant (t=3.063, P=0.022). The degree of carotid artery stenosis in the non-surgical treatment group markedly worsened after treatment compared with that before treatment, and the difference was statistically significant (t=4.820, P=0.001). MRA and SPECT/CT eZIS results showed good consistency in the evaluation of carotid artery stenosis before and after treatment (Kappa value=0.766, P<0.001).

Conclusion  SPECT/CT eZIS can non-invasively and visually evaluate the therapeutic effect of CEA on carotid artery stenosis, and its method is simple and consistent with MRA.