在本研究中，我们使用扩散加权成像（DWI）沿脑血管周围空间的扩散加权图像分析（DWI-ALPS）方法评估了全脑放疗后间质液体动力学的变化。DWI-ALPS方法是扩散张量图像ALPS（DTI-ALPS）方法的简化版本，使用了带有正交运动探测梯度（MPGs）的扩散加权成像（DWI）。这项回顾性研究包括22位接受全脑放疗治疗的脑瘤患者的47套图像，对照组数据包括105名无病理变化的参与者的105套图像。DWI使用了三个MPGs按正交方向应用于成像平面，并回溯生成了x、y和z轴的视觉扩散系数图像。计算ALPS指数以量化间质液体动力学。使用独立样本t检验比较全脑放疗组和正常对照组的ALPS指数。将患者分为所有年龄组和各个年龄组（20-39、40-59和60-84岁）进行比较。我们还检查了生物等效剂量（BEDs）与ALPS指数之间的相关性，以及白质高信号和ALPS指数之间的相关性。在所有年龄组的比较中，全脑放疗组的ALPS指数（1.32±0.16）显著低于对照组（1.44±0.17）（p < 0.001），表明全脑放疗后患者的间质液体动力学发生了改变。还发现了显著的年龄组差异（40-59岁：p < 0.01；60-84岁：p < 0.001），以及BEDs的弱负相关性（r = -0.19）和白质高信号与ALPS指数的显著相关性（脑室周围白质：r = -0.46，深部白质：r = -0.38）。结论是使用带有正交MPGs的DWI的ALPS方法暗示了全脑放疗后患者间质液体动力学的改变。需要进一步的系统前瞻性研究来研究其与认知症状的关联。© 2023 The Authors. NMR in Biomedicine由John Wiley & Sons Ltd.发布。

In the current study, we assessed changes in interstitial fluid dynamics resulting after whole-brain radiotherapy using the diffusion-weighted image analysis along the perivascular space (DWI-ALPS) method, which is a simplified variation of the diffusion tensor image ALPS (DTI-ALPS) method using diffusion-weighted imaging (DWI) with orthogonal motion-probing gradients (MPGs). This retrospective study included 47 image sets from 22 patients who underwent whole-brain radiotherapy for brain tumors. The data for the normal control group comprised 105 image sets from 105 participants with no pathological changes. DWI was performed with the three MPGs applied in an orthogonal direction to the imaging plane, and apparent diffusion coefficient images for the x-, y-, and z-axes were retrospectively generated. The ALPS index was calculated to quantify interstitial fluid dynamics. The independent t-test was used to compare the ALPS index between normal controls and patients who underwent whole-brain radiotherapy. Patients were compared in all age groups and individual age groups (20-39, 40-59, and 60-84 years). We also examined the correlation between biologically equivalent doses (BEDs) and the ALPS index, as well as the correlation between white matter hyperintensity and the ALPS index. In the comparison of all age groups, the ALPS index was significantly lower (p < 0.001) in the postradiation group (1.32 ± 0.16) than in the control group (1.44 ± 0.17), suggesting that interstitial fluid dynamics were altered in patients following whole-brain radiotherapy. Significant age group differences were found (40-59 years: p < 0.01; 60-84 years: p < 0.001), along with a weak negative correlation between BEDs (r = -0.19) and significant correlations between white matter hyperintensity and the ALPS index (r = -0.46 for periventricular white matter, r = -0.38 for deep white matter). It was concluded that the ALPS method using DWI with orthogonal MPGs suggest alteration in interstitial fluid dynamics in patients after whole-brain radiotherapy. Further systematic prospective studies are required to investigate their association with cognitive symptoms.© 2023 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd.