Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy.
Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy.
Mult Scler Relat Disord. 2019 Jan;27:294-297. doi: 10.1016/j.msard.2018.11.011. Epub 2018 Nov 13.
Peak width of skeletonized mean diffusivity (PSMD) is a novel and fully automated, MRI biomarker, which has shown clinical relevance in cerebral small vessel diseases (SVD). We aimed here to assess PSMD levels across the brain of patients with multiple sclerosis (MS), in comparison to normal controls (NC) and patients with CADASIL, a genetically defined form of severe SVD.
We assessed PSMD in relapsing-remitting (RR) MS patients (n = 47) in comparison to age-matched CADASIL patients (n = 25) and NC (n = 28). Diffusion Tensor Imaging data were acquired on 1.5T MR clinical scanner to automatically compute PSMD through "skeletonization" of WM tracts and diffusion histograms.
RRMS had lower WM lesion volume (LV) than CADASIL (8.6 ± 8.2 vs 24.4 ± 17.4 cm, p < 0.001). After correction for LV, PSMD values in MS were higher than in CADASIL patients (adjusted mean values: 4.5 vs 3.9 × 10 mm/s, p = 0.03) and in both patient groups were higher than in NC (2.8 ± 0.3 × 10 mm/s, p < 0.001). PSMD values correlated with LV in both patient groups (r = 0.8, p < 0.001 in MS; r = 0.6, p = 0.002 in CADASIL).
In both patient groups, PSMD was higher than in NC and closely correlated with LV, suggesting sensitivity in assessing brain tissue damage in these disorders. In MS patients, PSMD levels were higher than in CADASIL patients, despite the lower LV. This might be related to more severe normal-appearing WM abnormalities occurring in the MS brains. This novel, fully automated, MRI metric may represent a useful marker for a robust quantification of the diffuse WM tissue damage in MS.
骨化平均弥散率峰值（PSMD）是一种新颖的、完全自动化的 MRI 生物标志物，已在脑小血管疾病（SVD）中显示出临床相关性。我们旨在评估多发性硬化症（MS）患者脑内的 PSMD 水平，并与正常对照组（NC）和 CADASIL 患者（一种遗传性 SVD 严重形式）进行比较。
我们评估了 47 例复发缓解型 MS 患者（RRMS）、25 例年龄匹配的 CADASIL 患者和 28 例 NC 的 PSMD。使用 1.5T 磁共振临床扫描仪采集弥散张量成像数据，通过 WM 束的“骨化”和扩散直方图自动计算 PSMD。
RRMS 的脑白质病变体积（LV）低于 CADASIL（8.6±8.2 与 24.4±17.4 cm，p<0.001）。在校正 LV 后，MS 患者的 PSMD 值高于 CADASIL 患者（调整后的平均值：4.5 与 3.9×10 mm/s，p=0.03），且在这两组患者中均高于 NC（2.8±0.3×10 mm/s，p<0.001）。在两组患者中，PSMD 值与 LV 均呈正相关（RRMS 中 r=0.8，p<0.001；CADASIL 中 r=0.6，p=0.002）。
在两组患者中，PSMD 均高于 NC，与 LV 密切相关，提示其在评估这些疾病中的脑组织损伤方面具有敏感性。在 MS 患者中，尽管 LV 较低，但 PSMD 水平仍高于 CADASIL 患者。这可能与 MS 患者大脑中更严重的正常表现 WM 异常有关。这种新颖的、完全自动化的 MRI 指标可能是一种有用的标志物，可用于对 MS 弥漫性 WM 组织损伤进行稳健定量。
