Kanzawa Jun, Amemiya Shiori, Takao Hidemasa, Abe Osamu
Department of Radiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
J Neuroimaging. 2025 Sep-Oct;35(5):e70082. doi: 10.1111/jon.70082.
This study aims to characterize hemodynamic alterations in gliomas by analyzing global signal metrics and amplitude of low-frequency fluctuations (ALFF).
We analyzed resting-state functional MRI data from an open dataset. A total of 29 glioma patients (17 men; mean age: 44.2 ± 13.9 years; 16 high-grade) were included. Global signal cross-correlation (GSXC), representing the maximum cross-correlation value between each voxel's time series and the average gray matter signal of the contralateral hemisphere, and ALFF were calculated. Regions of interest for tumor were defined and mirrored to the contralateral side for comparison. Linear mixed-effects models were used to examine effects of tumor grade and measurement side on GSXC and ALFF. Post hoc analyses compared tumor versus contralateral regions.
GSXC was significantly reduced in tumor regions compared to the contralateral hemisphere, regardless of tumor grade (low-grade: 0.31 ± 0.21 vs. 0.45 ± 0.16, p = 0.005; high-grade: 0.39 ± 0.17 vs. 0.55 ± 0.13, p < 0.001). ALFF was significantly lower in low-grade tumors compared to the contralateral side (0.65 ± 0.15 vs. 0.77 ± 0.14, p = 0.005), while no significant difference was found in high-grade tumors (0.80 ± 0.18 vs. 0.77 ± 0.10, p = 0.46).
Our findings suggest that GSXC and ALFF provide complementary pathological information on glioma. GSXC indicates impaired cerebrovascular reactivity due to gliovascular uncoupling, whereas ALFF shows an increase in high-grade gliomas likely reflecting greater total vascularity.
本研究旨在通过分析整体信号指标和低频波动幅度（ALFF）来描述胶质瘤的血流动力学改变。
我们分析了来自一个公开数据集的静息态功能磁共振成像数据。共纳入29例胶质瘤患者（17例男性；平均年龄：44.2±13.9岁；16例高级别）。计算了整体信号互相关（GSXC），其代表每个体素时间序列与对侧半球平均灰质信号之间的最大互相关值，以及ALFF。定义肿瘤感兴趣区并镜像至对侧进行比较。采用线性混合效应模型来检验肿瘤分级和测量侧对GSXC和ALFF的影响。事后分析比较肿瘤区域与对侧区域。
与对侧半球相比，肿瘤区域的GSXC显著降低，无论肿瘤分级如何（低级别：0.31±0.21对0.45±0.16，p = 0.005；高级别：0.39±0.17对0.55±0.13，p < 0.001）。低级别肿瘤的ALFF显著低于对侧（0.65±0.15对0.77±0.14，p = 0.005），而高级别肿瘤未发现显著差异（0.80±0.18对0.77±0.10，p = 0.46）。
我们的研究结果表明，GSXC和ALFF为胶质瘤提供了互补的病理信息。GSXC表明由于胶质血管解偶联导致脑血管反应性受损，而ALFF显示高级别胶质瘤增加，可能反映了总血管数量增加。
