Wang S, Poptani H, Bilello M, Wu X, Woo J H, Elman L B, McCluskey L F, Krejza J, Melhem E R
Division of Neuroradiology, Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA.
AJNR Am J Neuroradiol. 2006 Jun-Jul;27(6):1234-8.
Diffusion tensor imaging (DTI) allows direct visualization and volumetric analysis of the corticospinal tract (CST). The purpose of this study was to determine whether color maps and fiber tracking derived from DTI data are valuable in detecting and quantifying CST degeneration in patients with amyotrophic lateral sclerosis (ALS).
Sixteen patients with ALS with clinical signs of upper motor neuron (UMN) involvement and 17 healthy subjects were studied with the use of DTI. Disease severity was determined by means of the ALS Functional Rating Scale-Revised (ALSFRS-R) and an UMN involvement score. DTI was acquired with a 12-direction, single-shot, spin-echo echo-planar sequence. The CST from the lower pons to the corona radiata at the level of the corpus callosum on 4 contiguous coronal sections was manually segmented by using color maps generated from the DTI data. The left and right CST volumes were measured separately and normalized to the total intracranial volume. Normalized CST volumes were compared between patients with ALS and healthy subjects.
The CST volumes of patients with ALS were significantly reduced (P < .01, unpaired t test) compared with healthy subjects, in both affected and nonaffected hemispheres. No significant correlation was found between CST volumes and any of the clinical parameters, including disease duration, ALSFRS-R, or UMN involvement score.
This study shows that volumetric analysis by using DTI-based color maps is valuable in detecting and monitoring structural degeneration of the CST. This will lead to objective and quantitative assessment of axonal degeneration in ALS.
扩散张量成像（DTI）可直接显示皮质脊髓束（CST）并进行容积分析。本研究旨在确定源自DTI数据的彩色图谱和纤维追踪在检测和量化肌萎缩侧索硬化症（ALS）患者的CST退变方面是否有价值。
对16例有上运动神经元（UMN）受累临床体征的ALS患者和17名健康受试者进行DTI研究。通过ALS功能评定量表修订版（ALSFRS-R）和UMN受累评分来确定疾病严重程度。采用12方向单次激发自旋回波平面序列采集DTI数据。利用DTI数据生成的彩色图谱，在4个连续冠状层面上，手动分割从脑桥下部到胼胝体水平的放射冠的CST。分别测量左右CST容积，并将其归一化至总颅内容积。比较ALS患者和健康受试者的归一化CST容积。
与健康受试者相比，ALS患者受累和未受累半球的CST容积均显著减小（P <.01，独立样本t检验）。未发现CST容积与任何临床参数之间存在显著相关性，包括病程、ALSFRS-R或UMN受累评分。
本研究表明，利用基于DTI的彩色图谱进行容积分析在检测和监测CST的结构退变方面具有重要价值。这将有助于对ALS患者的轴突退变进行客观定量评估。
