Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
PLoS One. 2013 Jul 2;8(7):e64207. doi: 10.1371/journal.pone.0064207. Print 2013.
Segmentation of brain MR images plays an important role in longitudinal investigation of developmental, aging, disease progression changes in the cerebral cortex. However, most existing brain segmentation methods consider multiple time-point images individually and thus cannot achieve longitudinal consistency. For example, cortical thickness measured from the segmented image will contain unnecessary temporal variations, which will affect the time related change pattern and eventually reduce the statistical power of analysis. In this paper, we propose a 4D segmentation framework for the adult brain MR images with the constraint of cortical thickness variations. Specifically, we utilize local intensity information to address the intensity inhomogeneity, spatial cortical thickness constraint to maintain the cortical thickness being within a reasonable range, and temporal cortical thickness variation constraint in neighboring time-points to suppress the artificial variations. The proposed method has been tested on BLSA dataset and ADNI dataset with promising results. Both qualitative and quantitative experimental results demonstrate the advantage of the proposed method, in comparison to other state-of-the-art 4D segmentation methods.
脑磁共振图像分割在研究大脑皮质的发育、老化和疾病进展变化的纵向研究中起着重要作用。然而,大多数现有的脑分割方法都是分别考虑多个时间点的图像,因此无法实现纵向一致性。例如,从分割图像中测量的皮质厚度将包含不必要的时间变化,这将影响与时间相关的变化模式,并最终降低分析的统计效力。在本文中,我们提出了一种具有皮质厚度变化约束的成人脑磁共振图像的 4D 分割框架。具体来说,我们利用局部强度信息来解决强度不均匀性问题,利用空间皮质厚度约束来保持皮质厚度在合理范围内,利用相邻时间点的皮质厚度变化约束来抑制人为变化。所提出的方法已经在 BLSA 数据集和 ADNI 数据集上进行了测试,取得了有希望的结果。定性和定量实验结果均表明,与其他最先进的 4D 分割方法相比,该方法具有优势。