Institute of Diagnostic and Interventional Radiology, Sixth Affiliated People's Hospital, Shanghai Jiao Tong University, Shanghai, China.
Orthopedics Department, Sixth Affiliated People's Hospital, Shanghai Jiao Tong University, Shanghai, China.
J Magn Reson Imaging. 2019 Jan;49(1):164-175. doi: 10.1002/jmri.26051. Epub 2018 Aug 30.
There are rare quantitative fiber density measurement techniques based on voxel measure changes of each corpus callosum (CC) subsegment with age.
To observe the regularity of corpus callosum development in normal aging from subvoxel to macroscopic volume.
Retrospective.
In all, 131 healthy volunteers divided into six age groups.
FIELD STRENGTH/SEQUENCE: 3T MR with 32-channel head coil T -3D and diffusion-weighted imaging with six b-values in a 30 directions sequence.
Track-density imaging (TDI) was used to visualize the complexity and the differences occurring in corpus callosum (CC) with age. TDI were reconstructed with a higher spatial voxel resolution of 0.1 mm subvoxel; TDI values are recognized as a subvoxel metric of real tract density. We reconstructed track density maps by using probabilistic streamline tractography combined with constrained spherical deconvolution. The CC was segmented into five subregions, and TDI, volume, and fractional anisotropy (FA) of each subregion in all the groups were measured using T W-3D images and compared.
Polynomial regression was done to between age and (CC1, CC2, CC3, CC4, CC5) of TDI/volume/FA. Multiple comparisons test two-way analysis of variance (ANOVA) were used to compare the differences between different age groups and sex groups in each subregion. Fisher's least significant difference test was used for the correction of the multiple comparisons.
From the 20-70 age groups, TDI values of CC2, CC3, and CC4 increased until 40 years, when they were highest, and then decreased. CC2 (7.35556, 7.56587, 8.06036, 7.53841, 6.6956, 6.56494), CC3 (7.75372, 8.41447, 9.13178, 8.72605, 7.50106, 5.69513), CC4 (8.63414, 9.1518, 9.22451, 9.03154, 8.11556, 7.1967). There was a significant difference in the CC3 TDI between the 50/60 years groups and the 60/70 years groups (P = 0.03853 and 0.00285, respectively). The volumes of CC2, CC3, and CC4 increased between 30 and 50 years and decreased between 50 and 60 years, CC2 (0.06557, 0.07244, 0.08062, 0.07353, 0.08576, 0.06294), CC3 (0.03421, 0.03867, 0.03891, 0.03916, 0.03058, 0.03658), CC4 (0.0242, 0.01948, 0.02445, 0.02887, 0.01938, 0.01956). FA of CC2, CC3, and CC4 decreased between years 40 and 60.CC2 (0.45981, 0.47392, 0.45654, 0.45702, 0.39982, 0.35767), CC3 (0.4628, 0.49056, 0.49701, 0.46667, 0.44795, 0.36799), CC4 (0.46599, 0.52887, 0.4971, 0.53257, 0.42861, 0.43158).
TDI had high sensitivity for the detection of age-related CC differences.
4 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:164-175.
有一些基于体素测量的定量纤维密度测量技术，可以根据每个胼胝体（CC）亚区的年龄变化来测量。
从亚像素到宏观体积观察正常老化过程中胼胝体的发育规律。
回顾性。
共有 131 名健康志愿者分为六个年龄组。
磁场强度/序列：3T MR 采用 32 通道头部线圈 T3D 和扩散加权成像，在 30 个方向序列中采用六个 b 值。
轨迹密度成像（TDI）用于可视化胼胝体（CC）随年龄变化的复杂性和差异。使用更高的空间体素分辨率 0.1mm 亚像素重建 TDI；TDI 值被认为是真实束密度的亚像素度量。我们使用概率流线追踪结合约束球分解重建了轨迹密度图。将 CC 分为五个亚区，使用 T1W-3D 图像测量并比较所有组的 TDI、体积和各亚区的各向异性分数（FA）。
用多项式回归分析年龄与（CC1、CC2、CC3、CC4、CC5）的 TDI/体积/FA 之间的关系。用双向方差分析（ANOVA）进行多组比较，比较不同年龄组和性别组之间各亚区的差异。采用 Fisher 最小显著差检验对多组比较进行校正。
从 20 岁到 70 岁，CC2、CC3 和 CC4 的 TDI 值在 40 岁时达到最高，然后下降。CC2（7.35556、7.56587、8.06036、7.53841、6.6956、6.56494），CC3（7.75372、8.41447、9.13178、8.72605、7.50106、5.69513），CC4（8.63414、9.1518、9.22451、9.03154、8.11556、7.1967）。50/60 岁组和 60/70 岁组 CC3 TDI 差异有统计学意义（P=0.03853 和 0.00285）。CC2、CC3 和 CC4 的体积在 30 岁到 50 岁之间增加，在 50 岁到 60 岁之间减少，CC2（0.06557、0.07244、0.08062、0.07353、0.08576、0.06294），CC3（0.03421、0.03867、0.03891、0.03916、0.03058、0.03658），CC4（0.0242、0.01948、0.02445、0.02887、0.01938、0.01956）。CC2、CC3 和 CC4 的 FA 在 40 岁到 60 岁之间下降。CC2（0.45981、0.47392、0.45654、0.45702、0.39982、0.35767），CC3（0.4628、0.49056、0.49701、0.46667、0.44795、0.36799），CC4（0.46599、0.52887、0.4971、0.53257、0.42861、0.43158）。
TDI 对检测年龄相关的 CC 差异具有很高的敏感性。
4 级技术功效：第 2 阶段 J. Magn. Reson. Imaging 2019；49:164-175。
