颈动脉支架术后CT灌注成像研究

目的 探讨CT灌注成像(CTP)评估颈动脉支架(CAS)术后1周与1年的预后关系.方法 选择单侧颈动脉狭窄程度≥60%,对侧颈动脉无明显狭窄的20例CAS术患者.患者术前1周内、术后1周及术后1年均行头颅CTP检查,计算得到患侧与对侧的各参数比值,包括相对血容量(rCBV)、相对血流量(rCBF)及相对平均通过时间(rMTT).术前1周内均行头颅MRI及CT平扫,且术后即刻行头颅CT平扫,术后1年均行头颈部血管造影.将20例患者3个时间点大脑前动脉区(ACA区)、大脑中动脉区(MCA区)、大脑后动脉区(PCA区)、基底节区、前后皮质分水岭区(cortical watershed,CWS)及髓质分水岭区(internal watershed,IWS)的rCBV、rCBF及rMTT参数值进行重复测量的方差分析.结果 术前1周内、术后1周及术后1年3个时间点各区的rCBV差界无统计学意义(P值均＞0.05),PCA区的rCBF、rMTT差异也无统计学意义(P值均＞0.05),余各区的rCBF、rMTT差异均有统计学意义(P值均＜0.01).20例CAS患者术前1周内、术后1周及术后1年rCBF:ACA区0.86±0.06、0.95±0.04、0.98±0.07,MCA区0.81±0.04、1.06±0.04、1.03±0.07,基底节0.84±0.06、0.97±0.04、0.96±0.04,前CWS区0.78±0.03、0.97±0.03、0.96±0.02,后CWS区0.77±0.03、1.00±0.02.0.98±0.03,IWS区0.80±0.04、0.94±0.03、0.93±0.04(F值分别为18.95、146.41、63.03、540.85、415.97、164.19,P值均＜0.01).rMTT:ACA区1.17±0.05、1.04±0.04、1.01±0.06,MCA区1.41±0.06、1.08±0.04、1. 07±0.04,基底节1.20±0.06、1.06±0.04、1.05±0.04,前CWS区1.41±0.05、1.10±0.05、1.09±0.04,后CWS区1.43±0.10、1.07±0.06、1.08±0.06,IWS区1.29±0.10、1.09±0.05、1.11±0.07(F值分别为51.74、248.89、70.08、381.68、288.94、41. 53,P值均＜0.01).两两比较显示,术后1周、1年与术前1周相比差异有统计学意义(P值均＜0.01),而术后1周与1年rCBF、rMTT差界无统计学意义(P值均＞0.05).结论 对于单侧颈动脉狭窄的患者,CAS术具有较好的长期预后.术后1周与术后1年的灌注情况相仿.CAS术后1周CTP复查对预测长期灌注变化具有重要意义.

Evaluation of hemodynamic outcomes after carotid artery stenting using cerebral perfusion CT

Objective To evaluate 1-week and 1-year outcomes of carotid artery stenting (CAS)using cerebral perfusion CT(PCT). Methods The clinical database of 20 patients with unilateral carotid artery stenosis( ≥60% ) who underwent CAS were retrospectively reviewed. Relative cerebral blood volume (rCBV), relative cerebral blood flow(rCBF) and relative mean transit time( rMTT) were measured by using cerebral PCT within one week before CAS and at one week and at one year after CAS. Cerebral MRI was performed within one week before CAS. The noncontrast CT was performed within one week before CAS and immediately after CAS. The arteriography was performed at one year after CAS. The variance analysis was performed to determine whether there were significant differences of rCBV, rCBF, rMTT in anterior cerebral artery area( ACA area), middle cerebral artery area( MCA area), posterior cerebral artery area( PCA area),basal ganglia area, front and back cortical watershed area( CWS area) and internal watershed area( IWS area) among the different time points. Results In the three measures, there was no significant difference of rCBV in all areas among the three time points( P ＞ 0. 05 ) , and there was no significant difference of rCBF and rMTT in PCA area( P ＞ 0. 05 ), but there were significant differences of rCBF and rMTT in all other areas among the three time ponits(P ＜0. 01). In one week before CAS, at one week and at one year after CAS, rCBF of 20 patients is 0. 86 ±0. 06, 0. 95 ±0. 04, 0. 98 ±0. 07 in ACA area, 0. 81 ±0. 04, 1.06 ±0. 04, 1.03 ±0.07 in MCA area, 0. 84 ±0. 06, 0. 97 ±0. 04, 0. 96 ±0. 04 in basal ganglia, 0. 78 ±0. 03,0. 97 ±0. 03, 0. 96 ±0. 02 in front CWS area, 0. 77 ±0. 03, 1.00 ±0. 02, 0. 98 ±0. 03 in back CWS area,and 0. 80 ± 0. 04, 0. 94 ± 0. 03, 0. 93 ± 0. 04 in IWS area ( F = 18. 95, 146. 41,63.03,540. 85,415.97,164.19, P＜0. 01). rMTT is 1.17 ±0.05, 1.04±0.04, 1.01 ±0.06 in ACA area, 1.41±0.06, 1.08±0.04, 1.07±0.04 in MCA area, 1.20±0.06, 1.06±0.04, 1.05±0.04 in basal ganglia, 1.41 ±0.05,1.10 ±0. 05, 1.09 ±0. 04 in front CWS area, 1.43 ±0. 10, 1.07 ±0. 06, 1.08 ±0. 06 in back CWS area,1.29±0.10, 1.09 ±0.05, 1.11 ±0.07 in IWS area (F=51.74, 248. 89, 70.08, 381.68, 288.94,41.53, P ＜0. 01 ). There were significant differences of rCBF and rMTT between those measured one week before CAS and one week or one year after CAS ( P ＜ 0. 01 ), but there were no significant differences of rCBF or rMTT in any area measured between those at 1 week after CAS and those measured at 1 year after CAS(P＞0.05). Conclusions Hemodynamic outcome at one year after CAS is good in the absence of contralateral carotid artery steno-occlusive disease. In addition, the coherence of results between 1-week and 1-year indicates that the outcome of one week after CAS could predict long-term hemodynamic outcome.