Constantinescu Clara, Ziegelitz Doerthe, Wikkelsø Carsten, Kern Silke, Jaraj Daniel, Rydén Lina, Westman Eric, Skoog Ingmar, Tullberg Mats
Hydrocephalus Research Unit, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Sweden.
Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sweden.
Neuroradiol J. 2024 Dec 9:19714009241303132. doi: 10.1177/19714009241303132.
Epidemiological studies on idiopathic normal pressure hydrocephalus (iNPH) imaging markers and their normal values are scarce. This population-based study aimed to analyze several morphologic and volumetric iNPH-related imaging markers in a large sample, determining their distribution, diagnostic accuracy, suggested cut-offs, and associations with iNPH symptoms.
This cross-sectional study included 791 70 year olds, 40 with radiologically probable iNPH (iNPH) and 751 without iNPH features (reference). MRI measures included Evans index (EI), z-EI, brain per ventricle ratio at anterior (BVR) and posterior commissures (BVR), sulcal compression, Sylvian fissure enlargement, callosal angle, diameter of temporal horns, 3 and 4 ventricles, midbrain, and pons. Volumes of ventricles, corpus callosum, and brainstem were computed using automated segmentation. ROC analysis determined imaging markers' cut-offs. Symptoms were evaluated clinically and through self-report.
In the reference group, median values (95% CI) for imaging markers were as follows: EI: 0.27 (0.26-0.27), z-EI: 0.28 (0.26-0.31), BVR: 1.69 (1.48-1.90), and BVR: 2.66 (2.24-3.27). Most imaging markers differed significantly between iNPH and the reference. Lateral ventricle volumes correlated better with z-EI and BVR than EI (Rs > 0.81 vs 0.68). Optimal cut-off values for z-EI, and BVR and BVR for distinguishing iNPH were 0.32, 1.36, and 1.83, respectively. Clinical symptoms correlated moderately with imaging markers (Rs < 0.49 for iNPH, < .01).
We report population-based reference values and propose cut-offs for iNPH-related imaging markers and volumetric measurements. Z-EI and BVR are likely superior markers for assessing ventricular enlargement in iNPH. Imaging markers of iNPH correlate moderately with iNPH symptoms.
关于特发性正常压力脑积水（iNPH）影像学标志物及其正常值的流行病学研究较少。这项基于人群的研究旨在分析大样本中几种与iNPH相关的形态学和容积性影像学标志物，确定它们的分布、诊断准确性、建议的临界值以及与iNPH症状的关联。
这项横断面研究纳入了791名70岁的老年人，其中40人经影像学检查可能患有iNPH（iNPH组），751人无iNPH特征（参照组）。MRI测量指标包括埃文斯指数（EI）、标准化埃文斯指数（z-EI）、前后连合处的脑室脑比率（BVR）、脑沟受压情况、大脑外侧裂增宽、胼胝体角、颞角直径、第三和第四脑室、中脑及脑桥。使用自动分割技术计算脑室、胼胝体和脑干的容积。通过ROC分析确定影像学标志物的临界值。通过临床评估和自我报告对症状进行评价。
在参照组中，影像学标志物的中位数（95%CI）如下：EI：0.27（0.26 - 0.27），z-EI：0.28（0.26 - 0.31），前连合处BVR：1.69（1.48 - 1.90），后连合处BVR：2.66（2.24 - 3.27）。大多数影像学标志物在iNPH组和参照组之间存在显著差异。侧脑室容积与z-EI和BVR的相关性优于与EI的相关性（Rs分别为>0.81和>0.68，而与EI的Rs为0.68）。用于区分iNPH 的z-EI、前连合处BVR和后连合处BVR的最佳临界值分别为0.32、1.36和1.83。临床症状与影像学标志物的相关性中等（iNPH组的Rs<0.49，P<0.01）。
我们报告了基于人群的参考值，并提出了与iNPH相关的影像学标志物和容积测量的临界值。Z-EI和BVR可能是评估iNPH脑室扩大的更优标志物。iNPH的影像学标志物与iNPH症状的相关性中等。
