Department of Radiology, Konkuk University Medical Center, Konkuk University School of Medicine, 120-1 Neungdong-ro, Gwangjin-gu, Seoul, 05030, Republic of Korea.
Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
Eur Radiol. 2019 Sep;29(9):4914-4921. doi: 10.1007/s00330-018-5836-x. Epub 2018 Nov 28.
White matter hyperintensities (WMHs) are implicated in the etiology of dementia. The underlying pathology of WMHs involves myelin and axonal loss due to chronic ischemia. We investigated myelin loss in WMHs and normal-appearing white matter (NAWM) in patients with various degrees of cognitive impairment using quantitative synthetic magnetic resonance imaging (MRI).
We studied 99 consecutive patients with cognitive complaints who underwent 3 T brain MRI between July 2016 and August 2017. Myelin partial volume maps were generated with synthetic MRI. Region-of-interest-based analysis was performed on these maps to compare the myelin partial volumes of NAWM and periventricular and deep WMHs. The effects of myelin partial volume of NAWMs on clinical cognitive function were evaluated using multivariate linear regression analysis.
WMHs were present in 30.3% of patients. Myelin partial volume in NAWM was lower in patients with WMHs than in those without (37.5 ± 2.7% vs. 39.9 ± 2.4%, p < 0.001). In patients with WMHs, myelin partial volume was highest in NAWMs (median [interquartile range], 37.2% [35.5-39.0%]), followed by deep WMHs (7.2% [3.2-10.5%]) and periventricular WMHs (2.1% [1.1-3.9%], p < 0.001). After adjusting for sex and education years, myelin partial volume in NAWMs was associated with the Clinical Dementia Rating Scale Sum of Box (β = -0.189 [95% CI, -0.380 to -0.012], p = 0.031).
Myelin loss occurs in both NAWM and WMHs of cognitively impaired patients. Synthetic MRI-based myelin quantification may be a useful imaging marker of cognitive dysfunction in patients with cognitive complaints.
• Quantitative synthetic MRI allows simultaneous acquisition of conventional MRI and myelin quantification without additional scanning time. • Normal-appearing and hyperintense white matter demonstrate myelin loss in cognitively impaired patients. • This myelin loss partially explains cognitive dysfunction in patients with cognitive complaints.
脑白质高信号（WMH）与痴呆的病因有关。WMH 的潜在病理学涉及由于慢性缺血导致的髓鞘和轴突丢失。我们使用定量合成磁共振成像（MRI）研究了不同认知障碍程度患者的 WMH 和正常表现的白质（NAWM）中的髓鞘丢失。
我们研究了 99 名连续有认知主诉的患者，他们在 2016 年 7 月至 2017 年 8 月之间接受了 3T 脑部 MRI。使用合成 MRI 生成髓鞘部分容积图。对这些地图进行基于感兴趣区域的分析，以比较 NAWM 和脑室周围及深部 WMH 的髓鞘部分容积。使用多元线性回归分析评估 NAWM 髓鞘部分容积对临床认知功能的影响。
30.3%的患者存在 WMH。与无 WMH 的患者相比，WMH 患者的 NAWM 髓鞘部分容积较低（37.5±2.7%比 39.9±2.4%，p<0.001）。在有 WMH 的患者中，NAWM 中的髓鞘部分容积最高（中位数[四分位间距]，37.2%[35.5-39.0%]），其次是深部 WMH（7.2%[3.2-10.5%]）和脑室周围 WMH（2.1%[1.1-3.9%]，p<0.001）。在校正性别和教育年限后，NAWM 的髓鞘部分容积与临床痴呆评定量表总分呈负相关（β=-0.189[95%CI，-0.380 至-0.012]，p=0.031）。
认知障碍患者的 NAWM 和 WMH 均存在髓鞘丢失。基于合成 MRI 的髓鞘定量可能是一种有用的成像标志物，可用于评估有认知主诉的患者的认知功能障碍。
• 定量合成 MRI 允许在不增加扫描时间的情况下同时采集常规 MRI 和髓鞘定量。 • 认知障碍患者的正常表现和高信号白质显示出髓鞘丢失。 • 这种髓鞘丢失部分解释了有认知主诉的患者的认知功能障碍。
