Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada.
Nova Scotia Health Authority, Halifax, NS, Canada.
Brain Behav. 2020 Jun;10(6):e01609. doi: 10.1002/brb3.1609. Epub 2020 Apr 18.
A new generation of large-scale studies is using neuroimaging to investigate adolescent brain development across health and disease. However, imaging artifacts such as head motion remain a challenge and may be exacerbated in pediatric clinical samples. In this study, we assessed the scan-rescan reliability of multimodal MRI in a sample of youth enriched for risk of mental illness.
We obtained repeated MRI scans, an average of 2.7 ± 1.4 weeks apart, from 50 youth (mean age 14.7 years, SD = 4.4). Half of the sample (52%) had a diagnosis of an anxiety disorder; 22% had attention-deficit/hyperactivity disorder (ADHD). We quantified reliability with the test-retest intraclass correlation coefficient (ICC).
Gray matter measurements were highly reliable with mean ICCs as follows: cortical volume (ICC = 0.90), cortical surface area (ICC = 0.89), cortical thickness (ICC = 0.82), and local gyrification index (ICC = 0.85). White matter volume reliability was excellent (ICC = 0.98). Diffusion tensor imaging (DTI) components were also highly reliable. Fractional anisotropy was most consistently measured (ICC = 0.88), followed by radial diffusivity (ICC = 0.84), mean diffusivity (ICC = 0.81), and axial diffusivity (ICC = 0.78). We also observed regional variability in reconstruction, with some brain structures less reliably reconstructed than others.
Overall, we showed that developmental MRI measures are highly reliable, even in youth at risk for mental illness and those already affected by anxiety and neurodevelopmental disorders. Yet, caution is warranted if patterns of results cluster within regions of lower reliability.
新一代的大规模研究利用神经影像学来研究健康和疾病状态下青少年大脑的发育。然而，成像伪影（如头部运动）仍然是一个挑战，在儿科临床样本中可能会更加严重。在这项研究中，我们评估了在富含精神疾病风险的青少年样本中，多模态 MRI 的扫描-再扫描可靠性。
我们从 50 名青少年（平均年龄 14.7 岁，标准差=4.4）中获得了重复的 MRI 扫描，平均相隔 2.7±1.4 周。样本的一半（52%）有焦虑症诊断；22%有注意力缺陷/多动障碍（ADHD）。我们使用测试-再测试的组内相关系数（ICC）来量化可靠性。
灰质测量具有很高的可靠性，平均 ICC 如下：皮质体积（ICC=0.90），皮质表面积（ICC=0.89），皮质厚度（ICC=0.82）和局部回环指数（ICC=0.85）。白质体积的可靠性极好（ICC=0.98）。弥散张量成像（DTI）成分也具有很高的可靠性。各向异性分数的测量最一致（ICC=0.88），其次是放射状弥散系数（ICC=0.84），平均弥散系数（ICC=0.81）和轴向弥散系数（ICC=0.78）。我们还观察到重建的区域变异性，一些脑结构的重建可靠性不如其他结构。
总体而言，我们表明，即使在有精神疾病风险的青少年和已经患有焦虑症和神经发育障碍的青少年中，发育性 MRI 测量也是高度可靠的。然而，如果结果模式集中在可靠性较低的区域，则需要谨慎。
