Automated Detection of Normal Pressure Hydrocephalus Using CT Imaging for Calculating the Ventricle-to-Subarachnoid Volume Ratio
Document Type
Article
Abstract
BACKGROUND AND PURPOSE: Normal pressure hydrocephalus (NPH) is a diagnostic challenge because its clinical symptoms and imaging appearance resemble normal aging and other forms of dementia. Identifying NPH is essential so that patients can receive timely treatment to improve gait distortion and quality of life. An automated marker of NPH was developed and evaluated on clinical CT images, and its utility was assessed in a large patient cohort. MATERIALS AND METHODS: A retrospective review was conducted of CT images from 306 tap test-responsive patients with NPH between January 2015 and January 2022. Control CT images were obtained from patients in the emergency department who were evaluated for headache and had unremarkable CT findings between June 2021 and August 2022. The ventricle-to-subarachnoid volume ratio (VSR) was automatically calculated by the imaging software and used as a predictor of NPH in linear regression modeling with adjustment for age and sex. The correlations of VSR with age, sex, and the receiver operating characteristic were computed. RESULTS: VSR was significantly greater in patients with NPH than controls (P < .001). Importantly, VSR was not significantly correlated with age (P = .56, R = 0.001). VSR identifies NPH with a sensitivity and specificity of 94.1% and 92.5%, respectively, with an area under the receiver operating characteristic curve of 0.99 (95% CI 0.975-0.995). CONCLUSIONS: Automated assessment of the VSR on head CT images identified probable NPH with 93% accuracy. The assessment of a large cohort of patients with NPH supports the generalizability of clinical screening of CT images. Moreover, the results support the utility of ventricle-to-sulcal concordance often used by radiologists but not currently a part of the accepted guidelines for imaging markers of NPH.
Medical Subject Headings
Humans; Hydrocephalus, Normal Pressure (diagnostic imaging); Female; Male; Aged; Retrospective Studies; Tomography, X-Ray Computed (methods); Middle Aged; Aged, 80 and over; Cerebral Ventricles (diagnostic imaging); Subarachnoid Space (diagnostic imaging); Sensitivity and Specificity
Publication Date
1-8-2025
Publication Title
AJNR. American journal of neuroradiology
E-ISSN
1936-959X
Volume
46
Issue
1
First Page
141
Last Page
146
PubMed ID
39746816
Digital Object Identifier (DOI)
10.3174/ajnr.A8451
Recommended Citation
Knittel, Jacob J.; Hoskin, Justin L.; Hoyt, Dylan J.; Abdo, Jonathan A.; Foldes, Emily L.; McElvogue, Molly M.; Oliver, Clay M.; Keesler, Daniel A.; Fife, Terry D.; Barranco, F David; Smith, Kris A.; McComb, J Gordon; Borzage, Matthew T.; and King, Kevin S., "Automated Detection of Normal Pressure Hydrocephalus Using CT Imaging for Calculating the Ventricle-to-Subarachnoid Volume Ratio" (2025). Neurosurgery. 2242.
https://scholar.barrowneuro.org/neurosurgery/2242