ZOOM or Non-ZOOM? Assessing Spinal Cord Diffusion Tensor Imaging Protocols for Multi-Centre Studies.
ZOOM or Non-ZOOM? Assessing Spinal Cord Diffusion Tensor Imaging Protocols for Multi-Centre Studies.
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DOI：
10.1371/journal.pone.0155557
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Gandini Wheeler-Kingshott CA
中科院分区：
文献类型：
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作者：
Samson RS;Lévy S;Schneider T;Smith AK;Smith SA;Cohen-Adad J;Gandini Wheeler-Kingshott CA
本研究的目的是开发和评估两种脊髓（SC）扩散张量成像（DTI）协议，在多个地点实施（使用来自两个不同制造商的扫描仪），一种可用于任何临床扫描仪，另一种使用目前可用的更高级选项研究环境，并使用自动化处理方法进行无偏量化。DTI参数对病变SC的变化敏感。然而，由于各种因素，包括其尺寸小、患者相关和生理运动以及场不均匀性，脊髓成像在技术上具有挑战性。诸如回波平面成像（EPI）的快速采集序列是期望的，但是可能遭受图像失真。我们提出了一个多中心比较两个采集协议上实现的扫描仪从两个不同的供应商（西门子和飞利浦），一个使用缩小的视野（rFOV）EPI序列，一个只使用选项，如外容积抑制（OVS）的标准临床扫描仪。使用脊髓磁共振成像仪进行自动分析，以无偏和可重复地量化白色物质中的DTI指标。使用rFOV序列采集的图像比单独使用OVS采集的图像失真更小。在所有部位使用两种序列获得的SC DTI参数值与之前在3 T下进行的测量结果一致。对于相同的扫描仪制造商，与OVS序列相比，rFOV序列的DTI参数部位间SD更小。与OVS序列相比，rFOV的研究中心间重现性更高（对于相同的制造商和采集细节，即在两个Philips研究中心采集的ZOOM数据），这支持了这样一种观点，即更广泛地使用rFOV等研究选项将提高多中心临床试验中获得的测量结果的准确性。未来的多中心研究还应旨在匹配来自不同制造商/研究中心的所有序列中的rFOV技术和信噪比，以避免测量的DTI参数的任何偏倚，并确保对病理变化的相似灵敏度。
The purpose of this study was to develop and evaluate two spinal cord (SC) diffusion tensor imaging (DTI) protocols, implemented at multiple sites (using scanners from two different manufacturers), one available on any clinical scanner, and one using more advanced options currently available in the research setting, and to use an automated processing method for unbiased quantification. DTI parameters are sensitive to changes in the diseased SC. However, imaging the cord can be technically challenging due to various factors including its small size, patient-related and physiological motion, and field inhomogeneities. Rapid acquisition sequences such as Echo Planar Imaging (EPI) are desirable but may suffer from image distortions. We present a multi-centre comparison of two acquisition protocols implemented on scanners from two different vendors (Siemens and Philips), one using a reduced field-of-view (rFOV) EPI sequence, and one only using options available on standard clinical scanners such as outer volume suppression (OVS). Automatic analysis was performed with the Spinal Cord Toolbox for unbiased and reproducible quantification of DTI metrics in the white matter. Images acquired using the rFOV sequence appear less distorted than those acquired using OVS alone. SC DTI parameter values obtained using both sequences at all sites were consistent with previous measurements made at 3T. For the same scanner manufacturer, DTI parameter inter-site SDs were smaller for the rFOV sequence compared to the OVS sequence. The higher inter-site reproducibility (for the same manufacturer and acquisition details, i.e. ZOOM data acquired at the two Philips sites) of rFOV compared to the OVS sequence supports the idea that making research options such as rFOV more widely available would improve accuracy of measurements obtained in multi-centre clinical trials. Future multi-centre studies should also aim to match the rFOV technique and signal-to-noise ratios in all sequences from different manufacturers/sites in order to avoid any bias in measured DTI parameters and ensure similar sensitivity to pathological changes.