Free water elimination improves test-retest reproducibility of diffusion tensor imaging indices in the brain: A longitudinal multisite study of healthy elderly subjects.
Free water elimination improves test-retest reproducibility of diffusion tensor imaging indices in the brain: A longitudinal multisite study of healthy elderly subjects.
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DOI：
10.1002/hbm.23350
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发表时间：
2017-01
影响因子：
4.8
通讯作者：
PharmaCog Consortium
中科院分区：
文献类型：
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作者：
Albi A;Pasternak O;Minati L;Marizzoni M;Bartrés-Faz D;Bargalló N;Bosch B;Rossini PM;Marra C;Müller B;Fiedler U;Wiltfang J;Roccatagliata L;Picco A;Nobili FM;Blin O;Sein J;Ranjeva JP;Didic M;Bombois S;Lopes R;Bordet R;Gros-Dagnac H;Payoux P;Zoccatelli G;Alessandrini F;Beltramello A;Ferretti A;Caulo M;Aiello M;Cavaliere C;Soricelli A;Parnetti L;Tarducci R;Floridi P;Tsolaki M;Constantinidis M;Drevelegas A;Frisoni G;Jovicich J;PharmaCog Consortium
脑扩散MRI中的游离水消除（FWE）已被证明可以改善健康和疾病中人类白质表征的组织特异性。相对于经典的扩散张量成像（DTI）模型，FWE也有望在纵向研究中提高对微观结构变化的敏感性。然而，尚不清楚这两种模型在测试-再测试可重复性方面是否存在差异。本研究通过扩展先前的纵向可重复性3T多点研究（10个点，7种不同的扫描仪模型），对50名健康老年人（55-80岁）进行两次扫描，间隔至少一周，比较了FWE和DTI的双张量模型。我们计算了常用的DTI指标（FA：分数各向异性，MD：平均扩散率，RD：径向扩散率和AXD：轴向扩散率）的可重复性，这些指标是使用DTI模型或FWE模型导出的。在JHU-ICBM-DTI-81白质标签图谱的48个白质区域评估DTI指标，并评估再现性误差。我们发现，相对于DTI模型，FWE在大多数测试区域显著降低了可重复性误差。特别是，对于FA和MD指标，可重复性误差平均降低了约1%。重复性评分在不同位点间无显著差异。这项研究表明，FWE提高了敏感性，因此有望用于临床应用，有可能识别更细微的变化。增加的可重复性允许在评估疾病进展或治疗效果的生物标志物的研究中使用更小的样本量或更短的试验。
Free water elimination (FWE) in brain diffusion MRI has been shown to improve tissue specificity in human white matter characterization both in health and in disease. Relative to the classical diffusion tensor imaging (DTI) model, FWE is also expected to increase sensitivity to microstructural changes in longitudinal studies. However, it is not clear if these two models differ in their test-retest reproducibility. This study compares a bi-tensor model for FWE with DTI by extending a previous longitudinal-reproducibility 3T multisite study (10 sites, 7 different scanner models) of 50 healthy elderly participants (55–80 years old) scanned in two sessions at least one week apart. We computed the reproducibility of commonly used DTI metrics (FA: fractional anisotropy, MD: mean diffusivity, RD: radial diffusivity and AXD: axial diffusivity), derived either using a DTI model or a FWE model. The DTI metrics were evaluated over 48 white matter regions of the JHU-ICBM-DTI-81 white-matter labels atlas, and reproducibility errors were assessed. We found that relative to the DTI model, FWE significantly reduced reproducibility errors in most areas tested. In particular, for the FA and MD metrics there was an average reduction of approximately 1% in the reproducibility error. The reproducibility scores did not significantly differ across sites. This study shows that FWE improves sensitivity and is thus promising for clinical applications, with the potential to identify more subtle changes. The increased reproducibility allows for smaller sample size or shorter trials in studies evaluating biomarkers of disease progression or treatment effects.