Ding Xiao-Qi, Kucinski Thomas, Wittkugel Oliver, Goebell Einar, Grzyska Ulrich, Görg Maria, Kohlschütter Alfried, Zeumer Hermann
Department of Neuroradiology, University Hospital Hamburg-Eppendorf, University of Hamburg, Germany.
Invest Radiol. 2004 Dec;39(12):740-6. doi: 10.1097/00004424-200412000-00005.
We studied age-related changes in T2 relaxation times from the normal maturating human brain under routine clinical MR examination conditions.
In 70 healthy subjects aged between 3 weeks and 39 years, T2 maps of the brain in which the intensity of each pixel corresponded to T2 relaxation times were generated based on magnetic resonance imaging data collected with a triple spin echo sequence. T2 relaxation times in white matter (WM) and gray matter (GM) were measured in 6 distinctive regions of interest of the T2 maps. The age dependence of the T2 values was mathematically simulated using a biexponential function.
T2 values were largest at the age of 3 weeks (maximum: approximately 400 milliseconds for WM and 200 milliseconds for GM) and decreased continuously with increasing age, faster in the first few months and slower thereafter, until values achieved between 95 and 110 milliseconds for WM and 88 and 95 milliseconds for GM in adults. The relationship between T2 values and age could be well simulated using a biexponential function (R > 0.92).
T2 relaxation time correlates well with the progress of brain maturation. The used biexponential function reflects the dynamic development of myelination in newborns and young children as well as the maturation of myelination during adolescence and could be used to develop a "normal" reference for neuroradiological diagnoses.
我们在常规临床磁共振检查条件下研究了正常成熟人脑T2弛豫时间的年龄相关变化。
对70名年龄在3周龄至39岁之间的健康受试者，基于用三重自旋回波序列收集的磁共振成像数据生成脑T2图，其中每个像素的强度对应于T2弛豫时间。在T2图的6个不同感兴趣区域测量白质（WM）和灰质（GM）的T2弛豫时间。使用双指数函数对T2值的年龄依赖性进行数学模拟。
T2值在3周龄时最大（最大值：WM约为400毫秒，GM约为200毫秒），并随着年龄增长持续下降，最初几个月下降较快，之后较慢，直至成年人的WM值达到95至110毫秒，GM值达到88至95毫秒。使用双指数函数可以很好地模拟T2值与年龄之间的关系（R>0.92）。
T2弛豫时间与脑成熟进程密切相关。所使用的双指数函数反映了新生儿和幼儿髓鞘形成的动态发展以及青少年期髓鞘形成的成熟过程，可用于建立神经放射学诊断的“正常”参考标准。
