A large body of literature exists on white matter (WM) abnormalities in individuals with anorexia nervosa (AN). However, these studies have primarily relied on the diffusion tensor imaging (DTI), a technique known for its limited ability to resolve complex WM fibre arrangements. To overcome limitations of DTI, this study employed fixel-based analysis (FBA) to investigate fibre-specific WM abnormalities in AN. FBA, which incorporates information on connectivity and crossing-fibres, offers greater anatomical specificity and interpretability than DTI. Twenty-six acute AN patients and thirty-one healthy controls underwent diffusion-weighted imaging scanning, and FBA and DTI metrics were compared between groups. Results revealed significant reductions in fibre-bundle cross-section within the anterior corona radiata and genu of corpus callosum, indicating morphological atrophy in AN patients. These specific tracts, identified by FBA, connect brain regions involved in the symptomatology of AN. DTI showed increased axial diffusivity in the cerebellar peduncles of AN patients but did not show significant differences in other metrics. Notably, there was no overlap between findings of FBA and DTI analyses. Overall, this study highlights the potential of FBA to detect WM abnormalities not accounted for by DTI and suggests that myelin loss contributes to the observed clinical picture in AN patients.

有大量关于神经性厌食症 (AN) 患者白质 (WM) 异常的文献。然而，这些研究主要依赖于扩散张量成像 (DTI)，这种技术因其解析复杂 WM 光纤排列的能力有限而闻名。为了克服 DTI 的局限性，本研究采用基于固定素的分析 (FBA) 来研究 AN 中纤维特异性 WM 异常。FBA 结合了连接性和交叉纤维的信息，提供比 DTI 更高的解剖特异性和可解释性。26 名急性 AN 患者和 31 名健康对照接受弥散加权成像扫描，并比较组间的 FBA 和 DTI 指标。结果显示，前放射冠和胼胝体膝部的纤维束横截面显着减少，表明 AN 患者存在形态萎缩。这些由 FBA 识别的特定神经束连接着与 AN 症状相关的大脑区域。DTI 显示 AN 患者小脑脚的轴向扩散率增加，但其他指标没有显示显着差异。值得注意的是，FBA 和 DTI 分析的结果之间没有重叠。总体而言，这项研究强调了 FBA 检测 DTI 无法解释的 WM 异常的潜力，并表明髓磷脂缺失有助于观察到 AN 患者的临床表现。