Silver N C, Barker G J, MacManus D G, Tofts P S, Miller D H
Department of Clinical Neurology, Institute of Neurology, London, UK.
J Neurol Neurosurg Psychiatry. 1997 Mar;62(3):223-8. doi: 10.1136/jnnp.62.3.223.
To establish a normative database for magnetisation transfer ratio (MTR) measurements in the white matter of healthy adult brains. Such MTR values were evaluated for regional variation and evidence of differences associated with aging, sex, and handedness.
Forty one healthy volunteers, ranging in age from 16 to 55 years, underwent axial brain magnetisation transfer (MT) imaging on a 1.5 Tesla magnetic resonance scanner. Calculated MT images allowed evaluation of MTR from specific regions within the corpus callosum, cerebral hemispheres, and pons.
Highest values were noted in the corpus callosum. No significant sex differences were seen for any region studied. Small but significant age related reductions in MTR were noted in the corpus callosum and other cerebral white matter regions studied. Comparing MTR values between young (16-35 years) and older (36-55 years) age groups, this was most apparent in the corpus callosum (40.82% units in the young group v 40.28% units in the older group, P < 0.05) and frontal white matter (39.65% units in the young group v 39.18% units in the older group, P < 0.005). In addition, values for MTR were analysed for evidence of hemispheric asymmetry. MTR values were higher in the left hemisphere for all regions studied, reaching significance in the centrum semiovale (37.75% units v 37.57% units, P < 0.05) and parieto-occipital white matter (37.67% units v 37.43% units, P < 0.05). No relation between such interhemispheric MTR differences and handedness was noted.
Magnetisation transfer imaging shows significant age related changes in normal brain white matter. In addition to regional variations in MTR in the normal brain, there seem to be small but significant variations in MTR between the cerebral hemispheres. It is important to consider such normal variations when evaluating MTR in pathological states.
建立健康成人大脑白质磁化传递率（MTR）测量的标准数据库。对这些MTR值进行区域差异评估以及与年龄、性别和利手相关差异的证据评估。
41名年龄在16至55岁之间的健康志愿者在1.5特斯拉磁共振扫描仪上接受了轴向脑磁化传递（MT）成像。通过计算得到的MT图像可评估胼胝体、大脑半球和脑桥特定区域的MTR。
胼胝体的MTR值最高。在所研究的任何区域均未发现显著的性别差异。在胼胝体和其他所研究的脑白质区域中，观察到与年龄相关的MTR有小但显著的降低。比较年轻（16 - 35岁）和年长（36 - 55岁）年龄组的MTR值，这在胼胝体中最为明显（年轻组为40.82%单位，年长组为40.28%单位，P < 0.05）以及额叶白质（年轻组为39.65%单位，年长组为39.18%单位，P < 0.00）。此外，分析MTR值以寻找半球不对称性的证据。在所研究的所有区域中，左半球的MTR值更高，在半卵圆中心（37.75%单位对37.57%单位，P < 0.05）和顶枕白质（37.67%单位对）37.43%单位，P < 0.05）达到显著水平。未观察到这种半球间MTR差异与利手之间的关系。
磁化传递成像显示正常脑白质中存在与年龄相关的显著变化。除了正常大脑中MTR的区域差异外，大脑半球之间的MTR似乎也存在小但显著的差异。在评估病理状态下的MTR时，考虑这些正常差异很重要。
