Behndig Sofia, Lalou Afroditi, Axelsson Jan, Larsson Jenny, Wåhlin Anders, Ryska Pavel, Slezak Ondrej, Riklund Katrine, Zizka Jan, Malm Jan, Eklund Anders
Department of Diagnostics and Intervention, Biomedical Engineering and Radiation Physics, Umeå University, Umeå, Sweden.
Umeå Center for Functional Brain Imaging (UFBI), Umeå University, Umeå, Sweden.
Fluids Barriers CNS. 2025 Jul 1;22(1):67. doi: 10.1186/s12987-025-00677-2.
Disproportionately enlarged subarachnoid space hydrocephalus (DESH) is a radiological biomarker for idiopathic normal pressure hydrocephalus (iNPH). DESH is a subjective measure, based on visual assessments, which may limit its reliability. The aim of this study was to develop and validate a method for the objective quantification of DESH.
By using a semiautomatic quantitative method, we calculated quantitative DESH (qDESH), defined as a ratio between CSF volumes at high convexities and Sylvian fissures. The analysis was based on three-dimensional T1-weighted images from 35 subjects with iNPH (mean age 74 yrs; 10 females) and 45 controls (mean age 72 yrs; 13 females). The interrater agreement for qDESH was evaluated by the intraclass correlation coefficient, and qDESH was compared with visual assessments performed by two neuroradiologists.
All subjects with iNPH and 13% of the controls visually scored DESH positive. The median qDESH was 2.48 (5th to 95th percentile 0.88 to 5.42) for iNPH and 0.63 (5th to 95th percentile 0.37 to 1.73) for the controls. The area under the receiver operating characteristic curve for qDESH was 0.95 (95% confidence interval 0.90-1) in separating iNPH patients from controls. The interrater agreement for qDESH was 0.99 (95% CI 0.986-0.994, p < 0.001).
Unlike visual DESH, qDESH generates a continuous variable, enabling reproducible quantification of DESH severity. With this method we can objectively investigate the diagnostic accuracy and prognostic assessment of DESH in iNPH.
蛛网膜下腔不成比例扩大性脑积水（DESH）是特发性正常压力脑积水（iNPH）的一种影像学生物标志物。DESH是一种基于视觉评估的主观指标，这可能会限制其可靠性。本研究的目的是开发并验证一种客观量化DESH的方法。
我们采用半自动定量方法计算定量DESH（qDESH），其定义为大脑镰旁脑沟和外侧裂脑脊液体积之比。分析基于35例iNPH患者（平均年龄74岁；10例女性）和45例对照者（平均年龄72岁；13例女性）的三维T1加权图像。通过组内相关系数评估qDESH的评分者间一致性，并将qDESH与两名神经放射科医生进行的视觉评估进行比较。
所有iNPH患者及13%的对照者视觉评分DESH为阳性。iNPH患者的qDESH中位数为2.48（第5至95百分位数为0.88至5.42），对照者为0.63（第5至95百分位数为0.37至1.73）。qDESH在区分iNPH患者与对照者时的受试者工作特征曲线下面积为0.95（95%置信区间0.90 - 1）。qDESH的评分者间一致性为0.99（95%CI 0.986 - 0.994，p < 0.001）。
与视觉DESH不同，qDESH产生一个连续变量，能够对DESH严重程度进行可重复的量化。通过这种方法，我们可以客观地研究DESH在iNPH中的诊断准确性和预后评估。
