Department of Neurosurgery, University of Tsukuba, Tsukuba, Japan.
J Neurosurg. 2010 Apr;112(4):832-9. doi: 10.3171/2009.7.JNS09550.
Ventriculomegaly is a common imaging finding in many types of conditions. It is difficult to determine whether it is related to true hydrocephalus or to an atrophic process by using only imaging procedures such as MR imaging after traumatic injury, stroke, or infectious disease. Diffusion tensor (DT) imaging can distinguish the compression characteristics of white matter, indicating that increased diffusion anisotropy may be related to white matter compression. In this preliminary study, the authors compared the DT imaging findings of ventriculomegaly with those of chronic hydrocephalus or atrophy to clarify the potential of diffusion anisotropy in the identification of hydrocephalus.
Ten patients with chronic hydrocephalus, 8 patients with atrophy (defined by conventional devices and surgical outcome), and 14 healthy volunteers underwent DT imaging. Images were acquired before and after shunting or once in cases without shunting. The fractional anisotropy (FA) values at many points around the lateral ventricle were evaluated.
The FA patterns around the lateral ventricle in the chronic hydrocephalus and atrophy groups were different. Especially in the caudate nucleus, FA was increased in the chronic hydrocephalus group compared with the atrophy group. Furthermore, the FA values returned to normal levels after shunt placement.
Assessment of the FA value of the caudate nucleus may be an important, less invasive method for distinguishing true hydrocephalus from ventriculomegaly. Further research in a large number of patients is needed to verify the diagnostic ability of this method.
脑室扩大是许多类型疾病的常见影像学表现。在创伤后、中风后或感染性疾病后，仅通过磁共振成像等影像学检查，很难确定其是否与真正的脑积水或萎缩过程有关。弥散张量（DT）成像可以区分白质的受压特征，表明扩散各向异性的增加可能与白质受压有关。在这项初步研究中，作者比较了脑室扩大的 DT 成像表现与慢性脑积水或萎缩的表现，以明确扩散各向异性在识别脑积水方面的潜力。
10 例慢性脑积水患者、8 例萎缩患者（根据常规设备和手术结果定义）和 14 例健康志愿者接受了 DT 成像检查。在分流前和分流后（无分流时进行一次）采集图像。评估了侧脑室周围许多点的各向异性分数（FA）值。
慢性脑积水组和萎缩组侧脑室周围的 FA 模式不同。特别是在尾状核，慢性脑积水组的 FA 高于萎缩组。此外，分流术后 FA 值恢复正常水平。
评估尾状核的 FA 值可能是一种重要的、无创的方法，可用于区分真正的脑积水和脑室扩大。需要对大量患者进行进一步研究，以验证该方法的诊断能力。
