Figley C R, Yau D, Stroman P W
Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada.
AJNR Am J Neuroradiol. 2008 Sep;29(8):1450-4. doi: 10.3174/ajnr.A1154. Epub 2008 Jun 4.
Recent literature indicates that cervical and upper-thoracic spinal cord motion adversely affect both structural and functional MR imaging (fMRI; particularly diffusion tensor imaging [DTI] and spinal fMRI), ultimately reducing the reliability of these methods for both research and clinical applications. In the present study, we investigated motion of the lower-thoracic, lumbar, and sacral cord segments to evaluate the incidence of similar motion-related confounds in these regions.
Recently developed methods, used previously for measuring cervical and upper-thoracic spinal cord motion, were employed in the present study to examine anteroposterior (A/P) and left-right (L/R) spinal cord motion in caudal regions. Segmented cinematic imaging was applied with a gradient-echo, turbo fast low-angle shot (turbo-FLASH) pulse sequence to acquire midline images of the cord at 24 cardiac phases throughout the lower-thoracic, lumbar, and sacral spinal cord regions.
The magnitude of A/P motion was found to be largest in rostral cord regions, whereas in caudal regions (at the level of the T4/T5 vertebrae and below), peak cord motion was uniformly small (routinely < or =0.10 mm). L/R motion, however, was found to be minimal throughout the thoracic, lumbar, and sacral regions.
Motion-related errors in spinal fMRI and DTI are expected to be significantly reduced throughout caudal regions of the spinal cord, thus yielding higher sensitivity and specificity compared with rostral regions. The paucity of such errors is expected to provide a means of observing the specific impact of motion (in rostral regions) and to enable the acquisition of uncorrupted DTI and fMRI data for studies of structure and function throughout lumbar and sacral regions.
近期文献表明，颈段和上胸段脊髓运动对结构和功能磁共振成像（功能磁共振成像；尤其是扩散张量成像[DTI]和脊髓功能磁共振成像）产生不利影响，最终降低了这些方法在研究和临床应用中的可靠性。在本研究中，我们调查了下胸段、腰段和骶段脊髓节段的运动情况，以评估这些区域中类似运动相关混淆因素的发生率。
本研究采用了先前用于测量颈段和上胸段脊髓运动的最新方法，来检查尾侧区域脊髓的前后（A/P）和左右（L/R）运动。应用梯度回波、快速低角度激发（turbo-FLASH）脉冲序列进行分段电影成像，以在整个下胸段、腰段和骶段脊髓区域的24个心动周期获取脊髓的中线图像。
发现A/P运动幅度在脊髓头侧区域最大，而在尾侧区域（T4/T5椎体及以下水平），脊髓运动峰值普遍较小（通常≤0.10 mm）。然而，发现L/R运动在整个胸段、腰段和骶段区域均最小。
预计脊髓功能磁共振成像和DTI中与运动相关的误差在脊髓尾侧区域会显著降低，因此与头侧区域相比，具有更高的敏感性和特异性。预计此类误差较少将提供一种观察（头侧区域）运动的特定影响的方法，并能够获取用于腰段和骶段区域结构和功能研究的未受干扰的DTI和功能磁共振成像数据。
