Good Correlation between CT-Measured Z-Evans’ Index and CT Volumetric of Ventricular System in Patients with iNPH Treated by Cerebrospinal Fluid Shunting
Issued Date
2024-10-01
Resource Type
ISSN
01252208
Scopus ID
2-s2.0-105007502659
Journal Title
Journal of the Medical Association of Thailand
Volume
107
Issue
10
Start Page
816
End Page
826
Rights Holder(s)
SCOPUS
Bibliographic Citation
Journal of the Medical Association of Thailand Vol.107 No.10 (2024) , 816-826
Suggested Citation
Chiewvit P., Ngamsombat C., Witthiwej T. Good Correlation between CT-Measured Z-Evans’ Index and CT Volumetric of Ventricular System in Patients with iNPH Treated by Cerebrospinal Fluid Shunting. Journal of the Medical Association of Thailand Vol.107 No.10 (2024) , 816-826. 826. doi:10.35755/jmedassocthai.2024.10.816-826-893 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/110699
Title
Good Correlation between CT-Measured Z-Evans’ Index and CT Volumetric of Ventricular System in Patients with iNPH Treated by Cerebrospinal Fluid Shunting
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Abstract
Background: Patients with idiopathic normal pressure hydrocephalus (iNPH) demonstrated an increase in the volume of lateral ventricles oriented along the Z-axial axis, as opposed to the X-axial axis. Objective: To determine which computed tomography (CT)-measured X-Evans’ index and Z-Evans’ index, exhibit a stronger correlation with CT-derived ventricular volume both before and after shunting procedures. Additionally, a comparative examination between those with iNPH characterized by disproportionate enlargement of subarachnoid space hydrocephalus (DESH) and those without DESH features. Materials and Methods: The present study enrolled forty-three iNPH patients who underwent shunting between April 2013 and April 2016. The initial screening involved a thorough review of pre-shunting CT images, leading to the categorization of patients into two distinct groups, those with DESH and without DESH features. Results: Both the X-Evans’ index and Z-Evans’ index exhibited a noteworthy correlation with ventricular volume, substantiated by correlation coefficients (r) of 0.777 (p<0.001) and 0.876 (p<0.001), respectively. Notably, the correlation between the change in CT ventricular volume and the change in Z-Evans’ index was more conspicuous in the overall patient cohort (r=0.730, p<0.001) than X-Evans’ index change (r=0.599, p<0.001). This tendency was particularly discernible within the DESH group, where the correlation with Z-Evans’ index (r=0.826, p<0.001). Conclusion: The Z-Evans’ index emerged as a more effective representation of ventricular volume compared to the X-Evans’ index in the entirety of the iNPH patient cohort. In contrast, during the subsequent CT follow-up, the change in X-Evans’ index exhibited superior efficacy in capturing the corresponding alterations in ventricular volume.