■该研究旨在(1)评估可行性约束球形反褶积(CSD)纤维束成像,以重建具有未镇静新生儿扩散MRI(dMRI)的交叉纤维束,(2)展示空间和角度分辨率以及处理设置对纤维束成像和衍生定量测量的影响。
■出于本研究的目的,来自局部队列的两个中度晚期早产儿(有或没有运动伪影)的术语等效dMRI(单壳b800和b2000,5b0和45个梯度方向)[中度晚期早产儿脑成像(BIMP)研究;卡尔加里,加拿大]和一名来自开发中的人类连接体项目的婴儿,具有高质量的dMRI(使用b2600外壳,包括20个B0和128个梯度方向,从多壳数据集中选择)。在b800和b2000dMRI上比较了扩散张量成像(DTI)和CSD纤维束成像。改变图像分辨率的修改,(预处理)和纤维束造影设置进行了测试,以评估其对纤维束造影的影响。每个实验都涉及可视化call体和皮质脊髓束的局部建模和纤维束成像,以及形态和扩散措施的评估。
■与DTI相反,CSD能够重建交叉纤维。纤维束成像对图像分辨率很敏感,(预处理)和纤维束造影设置。除了视觉变化,发现设置会影响流线计数,长度,和扩散措施(分数各向异性和平均扩散率)。扩散测量显示高达23%的变化。
■使用CSD纤维束造影和未镇静的新生儿dMRI数据重建交叉纤维束是可行的。迹线成像设置影响流线重建,保证仔细记录方法的可重复性和队列比较。
UNASSIGNED: The
study aimed to (1) assess the feasibility constrained spherical deconvolution (CSD) tractography to reconstruct crossing fiber bundles with unsedated neonatal diffusion MRI (dMRI), and (2) demonstrate the impact of spatial and angular resolution and processing settings on tractography and derived quantitative measures.
UNASSIGNED: For the purpose of this
study, the term-equivalent dMRIs (single-shell b800, and b2000, both 5 b0, and 45 gradient directions) of two moderate-late preterm infants (with and without motion artifacts) from a local cohort [Brain Imaging in Moderate-late Preterm infants (BIMP)
study; Calgary, Canada] and one infant from the developing human connectome project with high-quality dMRI (using the b2600 shell, comprising 20 b0 and 128 gradient directions, from the multi-shell dataset) were selected. Diffusion tensor imaging (DTI) and CSD tractography were compared on b800 and b2000 dMRI. Varying image resolution modifications, (pre-)processing and tractography settings were tested to assess their impact on
tractography. Each experiment involved visualizing local modeling and tractography for the corpus callosum and corticospinal tracts, and assessment of morphological and diffusion measures.
UNASSIGNED: Contrary to DTI, CSD enabled reconstruction of crossing fibers.
Tractography was susceptible to image resolution, (pre-) processing and
tractography settings. In addition to visual variations, settings were found to affect streamline count, length, and diffusion measures (fractional anisotropy and mean diffusivity). Diffusion measures exhibited variations of up to 23%.
UNASSIGNED: Reconstruction of crossing fiber bundles using CSD tractography with unsedated neonatal dMRI data is feasible. Tractography settings affected streamline reconstruction, warranting careful documentation of methods for reproducibility and comparison of cohorts.