Kearney Hugh, Yiannakas Marios C, Abdel-Aziz Khaled, Wheeler-Kingshott Claudia A M, Altmann Daniel R, Ciccarelli Olga, Miller David H
NMR Research Unit, Queen Square MS Centre, UCL Institute of Neurology, London, UK.
J Magn Reson Imaging. 2014 Mar;39(3):617-23. doi: 10.1002/jmri.24194. Epub 2013 Apr 30.
To identify an improved method for measuring spinal cord cross-sectional area (CSA) using magnetic resonance imaging (MRI) in multiple sclerosis (MS).
MRI was performed on 15 controls and 15 MS patients and repeated in nine controls and nine patients after 6 months. At this timepoint, an additional scan was acquired to evaluate scan-rescan reproducibility. Two sequences were acquired in the cervical cord: 3D phase sensitive inversion recovery (PSIR) and 3D magnetization prepared rapid acquisition T1-weighted gradient echo. CSA was outlined at C2-C3 using two methods: a semiautomated edge detection method and active surface model (ASM). We evaluated reproducibility for all combinations of sequences and analysis methods using coefficient of variation (COV) and intraclass correlation coefficient and performed sample size calculations for clinical trials to reduce longitudinal cord atrophy.
PSIR/ASM combination provided the lowest values of COV for intrarater, interrater, scan-rescan reproducibility (0.002%, 0.03%, and 0.1% respectively). At 6-month follow-up no significant changes were seen in CSA of controls, and a trend towards significance was observed in patients.
PSIR/ASM proved more reproducible than established methods of evaluating CSA in MS and also provides the lowest number of subjects per arm for 6-month and 1-year clinical trials.
确定一种在多发性硬化症（MS）中使用磁共振成像（MRI）测量脊髓横截面积（CSA）的改进方法。
对15名对照者和15名MS患者进行MRI检查，并在6个月后对9名对照者和9名患者重复检查。在这个时间点，额外进行一次扫描以评估扫描-再扫描的可重复性。在颈髓获取两个序列：三维相位敏感反转恢复（PSIR）序列和三维磁化准备快速采集T1加权梯度回波序列。使用两种方法在C2-C3水平勾勒CSA：半自动边缘检测法和主动表面模型（ASM）。我们使用变异系数（COV）和组内相关系数评估了序列和分析方法所有组合的可重复性，并进行了临床试验的样本量计算以减少脊髓纵向萎缩。
PSIR/ASM组合在同一观察者内、不同观察者间以及扫描-再扫描可重复性方面提供了最低的COV值（分别为0.002%、0.03%和0.1%）。在6个月的随访中，对照者的CSA未见显著变化，而患者中观察到有显著变化的趋势。
在MS中，PSIR/ASM被证明比既定的评估CSA的方法具有更高的可重复性，并且在6个月和1年的临床试验中，每组所需的受试者数量也是最少的。
