Neuroimaging Research Branch, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, USA.
Neuroimage. 2010 Oct 1;52(4):1347-54. doi: 10.1016/j.neuroimage.2010.05.001. Epub 2010 May 7.
Most current automated segmentation methods are performed on T(1)- or T(2)-weighted MR images, relying on relative image intensity that is dependent on other MR parameters and sensitive to B(1) magnetic field inhomogeneity. Here, we propose an image segmentation method based on quantitative longitudinal magnetization relaxation time (T(1)) of brain tissues. Considering the partial volume effect, fractional volume maps of brain tissues (white matter, gray matter, and cerebrospinal fluid) were obtained by fitting the observed signal in an inversion recovery procedure to a linear combination of three exponential functions, which represents the relaxations of each of the tissue types. A Look-Locker acquisition was employed to accelerate the acquisition process. The feasibility and efficacy of this proposed method were evaluated using simulations and experiments. The potential applications of this method in the study of neurological disease as well as normal brain development and aging are discussed.
目前大多数自动分割方法都是在 T(1)-或 T(2)-加权磁共振图像上进行的，依赖于相对的图像强度，而这种强度取决于其他磁共振参数，并对 B(1)磁场不均匀性敏感。在这里，我们提出了一种基于脑组织定量纵向磁化率弛豫时间（T(1)）的图像分割方法。考虑到部分容积效应，通过将观察到的反转恢复过程中的信号拟合到三个指数函数的线性组合，得到脑组织（白质、灰质和脑脊液）的部分容积图，这代表了每种组织类型的弛豫。采用 Look-Locker 采集来加速采集过程。使用模拟和实验评估了该方法的可行性和效果。讨论了该方法在神经病学研究以及正常大脑发育和衰老中的潜在应用。
