目的:由于非特异性症状和复杂的脑液压力动力学,脑积水是一种具有挑战性的神经外科疾病。通常,儿童脑积水的评估需要影像学或有创压力监测.尽管应力和剪切力在整个大脑中延伸,但通常定性地关注心室空间。这里,作者提出了一种基于MRI的矢量方法,用于体素脑和心室变形的可视化和分析。
方法:20名儿科患者(平均年龄7.7岁,范围6个月-18岁;14名男性)急性,在回顾性图表回顾后随机发现需要手术干预以缓解症状的新诊断脑积水.选择标准包括在3TMRI系统上进行的治疗前和治疗后配对3DT1加权容积MRI(3DT1-MRI)的采集。治疗前和治疗后3DT1-MRI对使用图像配准对齐,随后,执行体素非线性变换以得出顺应性的两个示例性可视化:1)全脑矢量图,其将所得变形场投影在基线轴向成像上;以及2)3D热图,其沿着心室边界和脑周边投影体积变化。
结果:患者接受了以下干预治疗脑积水:内镜下第三脑室造口术(n=6);外部脑室引流和/或肿瘤切除术(n=10);或脑室腹腔分流术(n=4)。术前和术后成像之间的平均时间为36.5天。干预之后,心室容积显著减少(治疗前和治疗后的平均容积分别为151.9cm3和82.0cm3;p<0.001,配对t检验).最大程度的变形矢量变化发生在侧脑室间隙,相对于genu和splenium。皮质层内变形矢量大小的变化与年龄之间存在显着相关性(p=0.011,Pearson),以及心室大小和年龄之间(p=0.014,Pearson),提示婴儿和年幼儿童的依从性更高。
结论:本研究强调了一种变形分析和矢量作图的方法,该方法可作为脑积水患者治疗性干预的地形可视化工具。将脑室变形程度或顺应性与颅内压相关的未来研究可以阐明该技术在无创压力监测或不顺应性脑室病例中的潜在作用。
OBJECTIVE: Hydrocephalus is a challenging neurosurgical condition due to nonspecific symptoms and complex brain-fluid pressure dynamics. Typically, the assessment of hydrocephalus in children requires radiographic or invasive pressure monitoring. There is usually a qualitative focus on the ventricular spaces even though stress and shear forces extend across the brain. Here, the authors present an MRI-based vector approach for voxelwise brain and ventricular deformation visualization and analysis.
METHODS: Twenty pediatric patients (mean age 7.7 years, range 6 months-18 years; 14 males) with acute, newly diagnosed hydrocephalus requiring surgical intervention for symptomatic relief were randomly identified after retrospective chart review. Selection criteria included acquisition of both pre- and posttherapy paired 3D T1-weighted volumetric MRI (3D T1-MRI) performed on 3T MRI systems. Both pre- and posttherapy 3D T1-MRI pairs were aligned using image registration, and subsequently, voxelwise nonlinear transformations were performed to derive two exemplary visualizations of compliance: 1) a whole-brain vector map projecting the resulting deformation field on baseline axial imaging; and 2) a 3D heat map projecting the volumetric changes along ventricular boundaries and the brain periphery.
RESULTS: The patients underwent the following interventions for treatment of hydrocephalus: endoscopic third ventriculostomy (n = 6); external ventricular drain placement and/or tumor resection (n = 10); or ventriculoperitoneal shunt placement (n = 4). The mean time between pre- and postoperative imaging was 36.5 days. Following intervention, the ventricular volumes decreased significantly (mean pre- and posttherapy volumes of 151.9 cm3 and 82.0 cm3, respectively; p < 0.001, paired t-test). The largest degree of deformation vector changes occurred along the lateral ventricular spaces, relative to the genu and splenium. There was a significant correlation between change in deformation vector magnitudes within the cortical layer and age (p = 0.011, Pearson), as well as between the ventricle size and age (p = 0.014, Pearson), suggesting higher compliance among infants and younger children.
CONCLUSIONS: This study highlights an approach for deformation analysis and vector mapping that may serve as a topographic visualizer for therapeutic interventions in patients with hydrocephalus. A future study that correlates the degree of cerebroventricular deformation or compliance with intracranial pressures could clarify the potential role of this technique in noninvasive pressure monitoring or in cases of noncompliant ventricles.