健康老年人脑单光子发射计算机体层摄影术及磁共振显像的研究

Brain single-photon emission computed tomography and magnetic resonance imaging studies in healthy elderly

目的 研究健康老年人脑的功能性和结构性影像学特征。方法 将 73名年龄≥ 6 0岁的健康志愿者按年龄分为 6 0～ 6 5岁组 (第 1组 )、6 6～ 70岁组 (第 2组 )和 >70岁组 (第 3组 ) ,采用单光子发射计算机体层摄影术对 3组进行脑组织检查 ,并对其中的 2 9名自愿者进行脑磁共振显像检查。结果 (1)经方差分析 ,第 2组和第 3组脑组织几乎所有部位 (除右丘脑和扣带回外 )的灌注均低于第 1组 ,其中第 2组右顶叶灌注的放射性计数比值 (RAR)为 0 87± 0 18,低于第 1组 (RAR =0 98±0 17;P <0 0 1) ;(2 )经配对t检验 ,除第 2组的双侧顶叶外 ,3组颞叶和顶叶的灌注均为右侧高于左侧(P <0 0 1和 0 0 5 ) ;(3)经方差分析 ,第 3组的灰质体积占颅内容积的百分比 [(47 5 9± 1 2 6 ) % ]小于第 2组 [(49 43± 1 30 ) % ],总脑脊液体积占颅内容积的百分比 [(14 6 1± 3 16 ) % ]大于第 1组[(12 41± 0 73) % ]和第 2组 [(11 94± 1 2 7) % ],右侧海马体积 [(2 0 4± 0 2 3)cm3 ]小于第 1组[(2 2 7± 0 2 0 )cm3 ],P均 <0 0 5。结论 健康老年人在脑血流灌注方面 ,存在颞顶叶灌注双侧不对称 ,右侧高于左侧 ,>6 5岁者以右顶叶的降低为著 ;在脑结构性变化方面 ,>70岁者以灰质。

Objective To figure out characteristic of functional and structural brain image in the healthy elderly Methods 73 healthy volunteers were divided into 3 groups:60 65 years(group1), 66 70(group2), and over 70 (group3) All subjects were examined with single photon emission computed tomography and 29 were examined with magnetic resonance imaging additionally Results (1)Perfusions were lower at almost all regions in group2 and group3 than in group1 Perfusion in the right parietal lobe in group2 was significantly lower than in group1 ( P <0 01) (2)Average perfusions were higher in the right temporal and parietal lobes than in the left in all 3 groups (3)Gray matter volumes were significantly smaller in group3 than in group2 ( P <0 05); total cerebral spinal fluids(CSF)volumes were significantly larger in group3 than in group1 and group2( P <0 05); right hippocampus volumes were significantly smaller in group3 than in group1 ( P <0 05) Conclusions Age related change of cerebral blood perfusions in the healthy elderly over 65 years is characterized with hypoperfusion in the right parietal The cerebral blood perfusion is higher in the right than in the left in the healthy elderly, especially in the temporal and parietal lobes Main brain structural changes in those aged over 70 years are manifested with grey matter and right hippocampus atrophy, and with increase of total CSF volumes