SPECT cerebral perfusion imaging and its quantitative analysis for the assessment of stent implantation for cerebral artery stenosis

Abstract

Objective To evaluate the role of SPECT cerebral perfusion imaging in assessing the stent implantation for cerebral artery stenosis. Methods A total of 35 patients (31 males, 4 females, average age (63.9±10.8) years) with cerebral artery stenosis confirmed by DSA for cerebral artery stent implantation were retrospectively analyzed. 99Tcm-ECD cerebral perfusion imaging was performed for all patients before and after stent implantation. The images were realigned and normalized by SPM 2.0 and then analyzed by Brain Search software for quantitative analysis. The brain was automatically separated to 210 functional areas according to Talarich map. The normalized averaged counts (NAC) of each area were calculated and compared with the data of 28 health controls(8 males, 20 females, average age (35.8±9.4) years). Less than 1.96s was defined as low perfusion lesions. The NAC values before and after stent implantation were compared for classifying improved from non-improved group. The mean number of lesions and Essen stroke risk score (ESRS) were analyzed between the two groups. The mean number of lesions and postoperative improvement rate of the internal carotid artery (ICA) occlusion and stenosis were compared. Paired rank sum test, two-sample t test, two-sample rank sum test and χ2 test were used for statistical analysis. Results In 35 patients with low perfusion areas, 20 were significantly improved after stent implantation. The mean number of lesions in the improved group(34.05±14.41) was significantly higher than that in the non-improved group (22.93±17.24; t=2.067, P 0.05). The mean number of the ICA occlusion lesions (34.36±14.31) was higher than that of the ICA stenosis lesions(31.35±16.37), but the difference was not statistically significant(t=0.498, P>0.05). The improvement rate of the ICA occlusion was higher than that of the ICA stenosis (7/11 vs 10/17), but the difference was not statistically significant(P>0.05). Conclusion SPECT cerebral perfusion imaging and its quantitative analysis can evaluate the low perfusion lesions before stent implantation and predict the perfusion improvement after stent implantation. Key words: Carotid stenosis; Stents; Tomography, emission-computed, single-photon; ECD