探讨不同输入动脉对烟雾病CT灌注参数的影响

The influence of different arterial input function for postprocessing of cerebral CT perfusion on the perfusion parameters in moyamoya disease

目的:探讨烟雾病CT灌注后处理过程中不同输入动脉对灌注参数的影响。方法:选取19例烟雾病患者术前行能谱CT容积穿梭扫描,在灌注图像后处理过程中,每例分别选择大脑前动脉A2段(ACA组)和基底动脉(BA组)作为输入动脉,上矢状窦为输出静脉,比较两组灌注参数间的差异;将ACA组、BA组的相对脑血流量(rCBF)分别与单光子发射计算机断层成像(SPECT)结果进行对比。所有资料均符合正态分布,采用配对t检验,P<0.05为差异具有统计学意义。结果:ACA组和BA组拟手术侧灌注参数对比:脑血流量(CBF)、达峰时间(TTP)差异均无统计学意义(P均>0.05),而脑血容量(CBV)、平均通过时间(MTT)差异均具有统计学意义(P均<0.05)。ACA组、BA组拟手术侧rCBF分别与对应SPECT结果比较:大脑前动脉、大脑中动脉分布区BA组与SPECT结果差异均无统计学意义(P均>0.05),而相应区域ACA组与SPECT结果差异均具有统计学意义(P均<0.05);大脑后动脉分布区BA组、ACA组与SPECT结果差异均无统计学意义(P均>0.05),但BA组更接近SPECT结果。结论:烟雾病CT灌注后处理过程中,输入动脉选择非受累动脉(BA)得到的灌注参数较选择受累动脉(ACA)更加准确,故在烟雾病患者行传统CT灌注扫描时,可适当调整扫描基线以使BA包括在扫描范围内。

Objective：To discuss the influence of different artery input on cerebral blood perfusion parameters of the moyamoya disease. Methods.. CT perfusion （CTP） datasets which were obtained from 19 preoperative moyamoya patients were retrospectively postprocessed using the same venous output function and different artery input function （AIF） selec- tions. The basilar artery （BA group） and the second segment of the anterior cerebral artery （ACA group） were used as the input arteries. CTP values obtained from different AIF were measured and compared. At last, the relative cerebral blood flow （rCBF） of the ACA group and BA group were compared with SPECT respectively, and paired t test was used. Results： Comparing the perfusion values of BA group with ACA group on the potential surgical side,the difference of CBV and MTT was statistically significant （P〈0.05）, while the difference of CBF and TTP was not. Comparing the rCBF of ACA and MCA distribution in the potential surgical side with SPECT, the difference with ACA group was statistically significant （P〈0.05） and the BA group was not （P〉0.05）, while on the PCA distribution, either ACA group or BA group had no statistical significance （P〉0.05）, but the mean value of BA group was closer to the SPECT. Conclusion： The use of ＂non-af- fected AIF can make the perfusion parameters more accurate. So the baseline of the conventional CT perfusion scanning can be adjusted so as to make the basilar artery included in the scan range.