优化时间分辨率以降低脑灌注CT辐射剂量:一项基于灌注参数评估的可行性与稳定性研究OA
Optimizing temporal resolution to reduce radiation dose in cerebral perfusion CT:a feasibility and stability study based on perfusion parameter assessment
目的 通过降低时间分辨率探究脑灌注CT成像在既满足诊断要求又降低辐射剂量的可行性.方法 本研究采用回顾性队列研究设计,纳入于2025年1-9月在陆军军医大学第一附属医院放射科因疑似卒中接受脑灌注成像检查的117例患者.设计并对比以下3种扫描方案,方案一(标准方案):全时间分辨率扫描,共采集21期图像(作为基线);方案二:对原始时间序列图像进行间隔1期采样(即每2期取1帧);方案三:保留对比剂达峰期及其前后各1期(共3期),对其余期相进行间隔1期采样.计算方案二、三相对于方案一的辐射剂量降低百分比.在核心梗死区或显著低灌注区勾画感兴趣区(regions of interest,ROI),测量并计算以下灌注参数的均值(mean)与标准差(SD):残余函数达峰时间(time to maximum of the residue function,Tmax)、平均通过时间(mean transit time,MTT)、脑血容量(cerebral blood volume,CBV)、脑血流量(cerebral blood flow,CBF).比较3种方案间各参数的统计学差异,同时比较3种方案计算的缺血半暗带体积差异.结果 方案二和方案三的辐射剂量较方案一分别显著降低约50.0%和42.9%.在灌注参数方面,3种方案间Tmax的SD值存在显著差异[F(1.92,222.42)=11.17,P＜0.001,偏η2=0.09],Bonferroni校正后的事后比较显示方案一与方案二、方案一与方案三的Tmax均值存在显著差异(P＜0.016 7),而方案二与方案三间无显著差异.MTT的均值在3种方案间无显著差异[F(1.88,218.11)=0.47,偏η2=0.004],但其SD值存在显著差异,Bonferroni校正后方案一与方案二、方案一与方案三差异显著(P＜0.016 7),方案二与方案三无显著差异.CBV的SD值在3种方案间存在显著差异[F(1.98,229.25)=22.97,P＜0.001,偏η2=0.17],而Friedman检验显示其均值无显著性差异.CBF的均值在3种方案间无显著性差异(Bonferroni校正后),但其SD值存在显著差异,Bonferroni校正后方案一与方案二、方案一与方案三差异显著(P＜0.016 7),方案二与方案三无显著差异.此外,Bonferroni校正后比较显示,3种方案计算的缺血半暗带体积均存在显著性差异(P＜0.016 7).结论 通过优化时间分辨率可显著降低CTP辐射剂量,且对核心灌注参数(MTT、CBV、CBF)的均值影响较小,CBF在低剂量方案中表现稳定,或可作为界定梗死核心的诊断依据.
Objective To investigate the feasibility of reducing radiation dose in cerebral perfusion CT(CTP)while maintaining diagnostic accuracy by optimizing temporal resolution.Methods This retrospective cohort study included 117 stroke-suspected patients undergoing CTP at the First Affiliated Hospital of Army Medical University from January to September 2025.Three protocols were designed:Protocol 1(full temporal resolution,21-phase acquisition,baseline),Protocol 2(every-other-phase sampling),Protocol 3(peak-enhancement+1/-1 phase retention with every-other-phase sampling for remaining phases).Radiation reduction percentages relative to Protocol 1 were calculated.Regions of interest(ROI)were placed in ischemic core/penumbra to measure mean±SD of perfusion parameters:time to maximum of the residue function(Tmax),mean transit time(MTT),cerebral blood volume(CBV)and cerebral blood flow(CBF).Inter-protocol differences were assessed,and ischemic penumbra volume discrepancies were also analyzed.Results Protocol 2 and 3 reduced radiation dose by 50.0%and 42.9%versus Protocol 1,respectively.For perfusion parameters:Tmax SD differed significantly across protocols[F(1.92,222.42)=11.17,P＜0.001,partial η2=0.09];post hoc tests showed significant mean differences between Protocol 1 vs 2(P＜0.016 7)and Protocol 1 vs 3(P＜0.016 7),but not Protocol 2 vs 3.MTT means showed no significant difference[F(1.88,218.11)=0.47,partial η2=0.004],though SD differed significantly between Protocol 1 vs 2 and 1 vs 3(P＜0.016 7).CBV SD differed significantly[F(1.98,229.25)=22.97,P＜0.001,partial η2=0.17]with no mean difference(Friedman test).CBF means showed no significant difference(Bonferroni-adjusted)but SD differed significantly between Protocol 1 vs 2 and 1 vs 3(P＜0.016 7).Ischemic penumbra volumes differed significantly across all protocols(P＜0.016 7).Conclusion Temporal resolution optimization significantly reduces CTP radiation dose while minimally impacting core perfusion parameters(MTT,CBV,CBF means).CBF remained stable across reduced-dose protocols and may serve as a reliable diagnostic criterion for infarct core delineation.
胡钧涛;李穗;刘云
重庆医科大学附属第二医院放射科,重庆||陆军军医大学(第三军医大学)第一附属医院放射科,重庆陆军军医大学(第三军医大学)第一附属医院放射科,重庆重庆医科大学附属第二医院放射科,重庆
医药卫生
脑卒中辐射剂量脑灌注体层摄影术X线计算机
strokeradiation dosebrain perfusiontomographyX-Ray computed
《陆军军医大学学报》 2026 (4)
461-469,9
重庆市自然科学基金面上项目(CSTB2023NSCQ-MSX0595)陆军军医大学第一附属医院博青创新基金(2024BQCXJJ-7) Supported by the General Program of Natural Science Foundation of Chongqing(CSTB2023NSCQ-MSX0595)and the Youth Innovation Fund for PhDs of the First Affiliated Hospital of Army Medical University(2024BQCXJJ-7).
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