Institute of Neuroradiology, Goethe University, Frankfurt am Main, Germany.
Neurosurgery. 2010 May;66(5):917-24. doi: 10.1227/01.NEU.0000367801.35654.EC.
Diffusion tensor imaging (DTI) parameters were investigated in patients with chronic idiopathic hydrocephalus to evaluate microstructural changes of brain tissue caused by chronic ventricular dilatation.
Eleven patients fulfilling the criteria for possible or probable idiopathic normal pressure hydrocephalus and 10 healthy control subjects underwent MRI at 3 Tesla, including DTI with 12 gradient directions. Patients were scanned before lumbar cerebrospinal fluid (CSF) withdrawal tests. Differences in fractional anisotropy (FA) and mean diffusivity (MD) between patients and controls were assessed using 2 different methods: manual definition of regions of interest and a fully automated method, TBSS (Tract-Based Spatial Statistics). DTI parameters were correlated with clinical findings.
Compared with the control group, patients with chronic idiopathic hydrocephalus had significantly higher MD values in both the periventricular corticospinal tract (CST) and the corpus callosum (CC), whereas FA values were significantly higher in the CST but lower in the CC. DTI parameters of the CST correlated with the severity of gait disturbances.
Microstructural changes in periventricular functionally relevant white matter structures (CSF, CC) in chronic idiopathic hydrocephalus can be visualized using DTI. Further studies should investigate the change of DTI parameters after CSF shunting and its relation to neurologic outcome.
通过弥散张量成像（DTI）参数研究慢性特发性脑积水患者，以评估慢性脑室扩张引起的脑组织微观结构变化。
11 名符合可能或可能的特发性正常压力性脑积水标准的患者和 10 名健康对照者在 3T 磁共振成像仪上进行检查，包括 12 个梯度方向的 DTI。患者在腰椎脑脊液（CSF）引流试验前进行扫描。使用 2 种不同的方法（手动定义感兴趣区和全自动方法 TBSS）评估患者与对照组之间各向异性分数（FA）和平均弥散度（MD）的差异。DTI 参数与临床发现相关。
与对照组相比，慢性特发性脑积水患者的脑室周围皮质脊髓束（CST）和胼胝体（CC）的 MD 值明显升高，而 CST 的 FA 值明显升高，CC 的 FA 值明显降低。CST 的 DTI 参数与步态障碍的严重程度相关。
DTI 可显示慢性特发性脑积水患者脑室周围与功能相关的白质结构（CSF、CC）的微观结构变化。进一步的研究应探讨 CSF 分流后 DTI 参数的变化及其与神经功能结局的关系。
