多标记后延迟时间动脉自旋标记成像在健康人脑解剖亚区血流定量分析中的应用

Application of multiple post labeling delay time arterial spin labeling imaging in the quantitative blood flow analysis of brain subregions in healthy adults

目的:基于多标记后延迟时间(Multi-PLD)动脉自旋标记(ASL)成像分析大脑半球、小脑半球及脑解剖亚区(56对)血流灌注正常参数范围,并探讨左右、性别及不同年龄组间差异。方法:2020年11月—2020年12月间招募本地42名健康成年志愿者,男性25名、女性17名,年龄23~74(38±14)岁,行7个PLD的ASL成像,其中青年组21名,男性15名、女性6名,年龄23~35岁;中老年组21名,男性10名、女性11名,年龄36~74岁。数据通过Cereflow软件离线处理得到动脉到达时间(ATT)和校正过的脑血流量(CBF)及脑血容量(CBV)灌注参数,再利用SimpleITK标准化函数根据解剖学自动标记模板(AAL)对计算的灌注图像进行标准化处理,最终得到脑解剖亚区的CBF、ATT、CBV灌注参数值。采用配对样本t检验、Wilcoxon秩和检验、独立样本t检验及Mann-Whitney U检验比较大脑半球、小脑半球及各脑解剖亚区左右两侧、不同性别、不同年龄组间灌注参数差异。采用Pearson相关分析比较灌注参数值与年龄的相关性。结果:大脑半球及多个脑解剖亚区62.5%(35/56)CBF、44.6%(25/56)CBV值表现为右侧高于左侧,多个脑解剖亚区28.6%(16/56)ATT值表现为左侧高于右侧。小脑半球CBF[(35.30±8.31)比(34.34±7.53)ml·100g^(-1)·min^(-1),P=0.021]、CBV[(0.47±0.11)比(0.45±0.09)ml/100g,P<0.001]、ATT[(1.30±0.10)比(1.24±0.11)s,P<0.001]均表现为左侧高于右侧。女性大脑半球、小脑半球及多个脑解剖亚区50.0%(28/56)CBF值高于男性,83.9%(47/56)ATT值<男性(P值均<0.05),CBV值仅在5组脑区(枕上回、枕中回、枕下回、顶上回、小脑7b区)高于男性(P值均<0.05)。青年组大脑半球及多个脑解剖亚区44.6%(25/56)CBF、33.9%(19/56)CBV值均高于中老年组(P值均<0.05)。青年组多数脑区的ATT值虽低于中老年组,但仅在直回(P=0.026)及中央旁小叶(P=0.006)差异有统计学意义。大脑半球的CBF(r=-0.430,P=0.005)、CBV(r=-0.327,P=0.035)与年龄呈负相关。多数不同年龄组间差异有统计学意义的脑解剖亚区的CBF(24/25,r范围-0.497~-0.343,P值均<0.05)、CBV(16/19,r范围-0.474~-0.322,P值均<0.05)与年龄均呈负相关,ATT与年龄呈正相关(直回:r=0.311,P=0.045;中央旁小叶:r=0.392,P=0.010)。结论:Multi-PLD ASL成像可以精确地定量分析脑组织血流灌注信息,多个脑解剖亚区灌注参数在不同侧别、性别及年龄组间存在差异,并且多数不同年龄组间存在差异脑区的灌注参数与年龄存在相关性。

Objective To explore the normal ranges of perfusion parameters between cerebral hemisphere,cerebellar hemisphere and brain anatomical subregions(56 pairs)in different gender and age groups with multiple post labeling delay time(Multi-PLD)arterial spin labeling(ASL)imaging.Methods From November 2020 to December 2020,42 healthy adult volunteers(Male 25,Female 17)were recruited to perform 7 PLD ASL imaging,including 21 young adults(15 males and 6 females,aged 23—35 years)and 21 seniors(10 males and 11 females,aged 36—74 years).The data was processed offline by Cereflow software to obtain arterial arrival time(ATT)and corrected cerebral blood flow(CBF)and cerebral blood volume(CBV)perfusion parameters.SimpleITK standardization function was used to standardize the calculated perfusion image according to the anatomical automatic labeling(AAL)template.Therefore,CBF,ATT,CBV perfusion values of brain subregions were obtained.Paired samples t test,Wilcoxon rank sum test,independent samples t test and Mann-Whitney U test were used to compare the differences of perfusion parameters in the cerebral hemisphere,the cerebellar hemisphere,brain subregions depending on side,gender and age.Pearson correlation analysis was used to compare the correlations of perfusion parameters with age.Results CBF in 62.5%(35/56)subregions and CBV in 44.6%(25/56)subregions were higher in right side than those in left side.ATT in most brain anatomical subregions(16/56)were higher in left side.The CBF[(35.30±8.31)vs.(34.34±7.53)ml·100g^(-1)·min^(-1),P=0.021],CBV[(0.47±0.11)vs.(0.45±0.09)ml/100g,P<0.001],ATT[(1.30±0.10)vs.(1.24±0.11)s,P<0.001]in left cerebellar hemisphere were higher than that of right side.The CBF(28/56)of cerebral hemisphere,cerebellar hemisphere and brain subregions was higher in females than that in males,while ATT in 83.9%(47/56)subregions was lower than that in males(all P<0.05).CBV in female subjects was higher only in 5 brain regions(superior occipital gyrus,middle occipital gyrus,inferior occipital gyrus,superior parietal gyrus and cerebelum_7b)(all P<0.05).In young subjects,CBF in 44.6%(25/56)subregions and CBV in 33.9%(19/56)subregions were higher than those in the senior group(all P<0.05).The ATT in most subregions in young group were lower than those in senior group,but the difference was statistically significant only in rectus gyrus(P=0.026)and paracentral lobule(P=0.006).The CBF(r=-0.430,P=0.005)and CBV(r=-0.327,P=0.035)of cerebral hemisphere were negatively correlated with age.The CBF(24/25,r range:-0.497—-0.343,all P<0.05)and CBV(16/19,r range:-0.474—-0.322,all P<0.05)in most subregions were negatively correlated with age,while ATT was positively correlated(gyrus rectus:r=0.311,P=0.045;paracentral lobule:r=0.392,P=0.010).Conclusions Multi-PLD ASL imaging could be applied for quantitative analysis of brain perfusion.The perfusion parameters of anatomical subregions are different depending on side,gender,and age.