Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Acad Radiol. 2012 Sep;19(9):1075-86. doi: 10.1016/j.acra.2012.04.012. Epub 2012 Jun 28.
A number of studies have reported decreases in fractional anistropy (FA) in amyotrophic lateral sclerosis using diffusion tensor imaging (DTI). The purpose of this study was to perform a meta-analysis in order to estimate the diagnostic test accuracy measures of DTI for the diagnosis of amyotrophic lateral sclerosis (ALS).
We searched MEDLINE (1966-April 2011), EMBASE (1999-April 2011), CINAHL (1999-April 2011), and Cochrane (2005-April 2011) databases to identify studies that measured FA in ALS subjects. Human, single-center studies using a DTI region of interest (ROI) or tractography techniques were used to compare FA values along the brain corticospinal tracts between ALS subjects and healthy controls. There were no language restrictions. Independent extraction of articles by 2 authors using predefined data fields including study quality indicators. We identified 30 case-control studies that used region of interest or tractography DTI techniques. We applied binormal receiver operative characteristic (ROC) curve analysis to assign specificity and sensitivity for each study. We applied the bivariate mixed-effects regression model using the Markov Chain Monte Carlo Simulation to calculate summary estimates for the sensitivity and specificity. We used the metan module in Stata, version 11.0, to calculate the area under the ROC curve, diagnostic odds ratio and the test effectiveness summary estimates.
The pooled sensitivity was 0.65 (95% CI 0.61-0.69); the pooled specificity, 0.67 (95% CI 0.63-0.72); the pooled diagnostic odds ratio, 1.88 (95% CI 1.46-2.30); the pooled test effectiveness, 1.04 (95% CI 0.81-1.27); and the pooled area under the ROC curve, 0.76 (95% CI 0.71-0.81). Subanalyses comparing magnetic resonance imaging (MRI) field strength (1.5T vs. 3.0T) and brain location (corticospinal tract average vs. internal capsule) revealed no significant differences in the test accuracy measures. Reference standard used for the diagnosis of ALS was the El Escorial criteria. There was at least moderate heterogeneity between the studies. True study quality is uncertain.
The discriminatory capability of DTI to make a diagnosis of ALS is only modest. There were no significant differences in the diagnostic test accuracy summary estimates with respect to MRI field strength or brain location.
多项研究应用弥散张量成像（DTI）报告肌萎缩侧索硬化症患者的各向异性分数（FA）降低。本研究旨在进行荟萃分析以评估 DTI 对肌萎缩侧索硬化症（ALS）诊断的诊断试验准确性指标。
我们检索了 MEDLINE（1966 年-2011 年 4 月）、EMBASE（1999 年-2011 年 4 月）、CINAHL（1999 年-2011 年 4 月）和 Cochrane（2005 年-2011 年 4 月）数据库，以确定测量 ALS 患者 FA 的研究。使用 DTI 感兴趣区（ROI）或束追踪技术的人类单中心研究用于比较 ALS 患者和健康对照组的大脑皮质脊髓束中的 FA 值。无语言限制。由 2 名作者独立使用预定义数据字段提取文章，包括研究质量指标。我们确定了 30 项使用 ROI 或束追踪 DTI 技术的病例对照研究。我们应用双正态接收者工作特征（ROC）曲线分析为每个研究分配特异性和敏感性。我们应用双变量混合效应回归模型使用马尔可夫链蒙特卡罗模拟计算敏感性和特异性的综合估计值。我们使用 Stata 版本 11.0 的 metan 模块计算 ROC 曲线下面积、诊断优势比和测试有效性综合估计值。
汇总的敏感性为 0.65（95% CI 0.61-0.69）；汇总的特异性为 0.67（95% CI 0.63-0.72）；汇总的诊断优势比为 1.88（95% CI 1.46-2.30）；汇总的测试效果为 1.04（95% CI 0.81-1.27）；汇总的 ROC 曲线下面积为 0.76（95% CI 0.71-0.81）。比较磁共振成像（MRI）场强（1.5T 与 3.0T）和脑位置（皮质脊髓束平均与内囊）的亚分析显示，测试准确性指标无显著差异。用于 ALS 诊断的参考标准为埃尔埃斯科里亚尔标准。研究之间存在中度至高度异质性。真实的研究质量不确定。
DTI 对 ALS 诊断的区分能力仅适度。MRI 场强或脑位置对诊断试验准确性综合估计值无显著影响。
