Volumetric Analysis from a Harmonized Multisite Brain MRI Study of a Single Subject with Multiple Sclerosis
Volumetric Analysis from a Harmonized Multisite Brain MRI Study of a Single Subject with Multiple Sclerosis
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DOI：
10.3174/ajnr.a5254
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发表时间：
2017-08-01
影响因子：
3.5
通讯作者：
Bakshi, R.
中科院分区：
文献类型：
--
作者：
Shinohara, R. T.;Oh, J.;Bakshi, R.
背景和目的：磁共振成像可用于测量多发性硬化症患者大脑的结构变化，对于诊断、纵向监测和治疗评估至关重要。北美多发性硬化症成像合作指导委员会制定了与脑病变和萎缩量化相关的统一高分辨率 3T MR 成像协议，并在美国 7 个地点实施。为了评估扫描数据的位点间变异性，我们对患有复发缓解型 MS 的志愿者进行了成像，并在每个位点进行了扫描-重新扫描。 材料和方法：所有成像均在西门子扫描仪（4 个 Skyra、2 个 Tim Trio 和 1 个 Verio）上采集。针对 T1 低信号和 T2 (FLAIR) 高信号病变手动获得专家分割。应用了几种自动病变检测和全脑、皮质和深层灰质体积管道。进行统计分析以评估不同部位的变异性，以及与部位相关的体积测量的系统偏差。结果：由于专家追踪的病变测量中的部位差异而导致的系统偏差是显着的（T1和T2病变体积的P <.01），部位解释了> 90％的变异（范围，T1中的13.0-16.4 mL和T2中的15.9-20.1 mL）病变体积。该站点还解释了大多数自动体积测量中超过 80% 的变化。输出测量根据扫描仪模型进行聚类，Skyra 与其他 2 个装置的结果相似。结论：即使在协议协调后扫描仪场强和制造商一致的多中心研究中，系统差异也可能导致体积分析中的严重偏差。
BACKGROUND AND PURPOSE: MR imaging can be used to measure structural changes in the brains of individuals with multiple sclerosis and is essential for diagnosis, longitudinal monitoring, and therapy evaluation. The North American Imaging in Multiple Sclerosis Cooperative steering committee developed a uniform high-resolution 3T MR imaging protocol relevant to the quantification of cerebral lesions and atrophy and implemented it at 7 sites across the United States. To assess intersite variability in scan data, we imaged a volunteer with relapsing-remitting MS with a scan-rescan at each site.MATERIALS AND METHODS: All imaging was acquired on Siemens scanners (4 Skyra, 2 Tim Trio, and 1 Verio). Expert segmentations were manually obtained for T1-hypointense and T2 (FLAIR) hyperintense lesions. Several automated lesion-detection and whole-brain, cortical, and deep gray matter volumetric pipelines were applied. Statistical analyses were conducted to assess variability across sites, as well as systematic biases in the volumetric measurements that were site-related.RESULTS: Systematic biases due to site differences in expert-traced lesion measurements were significant (P < .01 for both T1 and T2 lesion volumes), with site explaining >90% of the variation (range, 13.0-16.4 mL in T1 and 15.9-20.1 mL in T2) in lesion volumes. Site also explained >80% of the variation in most automated volumetric measurements. Output measures clustered according to scanner models, with similar results from the Skyra versus the other 2 units.CONCLUSIONS: Even in multicenter studies with consistent scanner field strength and manufacturer after protocol harmonization, systematic differences can lead to severe biases in volumetric analyses.