Evaluation of the Evan's Index on Normal Brain Computed Tomography Scans of Adults in Delta State Nigeria

The study aimed at establishing the normal Evans index (EI) in adults residing in Delta State, Nigeria.

Researchers sought ethical authorisation from a Nigerian University Teaching Hospital in Delta State, where this cross-sectional study was conducted. Computed tomographic images of the brain were retrieved from the hospital's radiological database. Brain computed tomography images of 195 adults (102 males and 93 females) were selected, and their axial slices were retrospectively analysed to determine the maximum width of the frontal horns (MWFHs) and the maximum intracranial transverse diameter (MITD). The ratio of MWFH to MITD was computed as the EI. Statistical Package for the Social Sciences version 27 was employed to evaluate the sex- and age-related differences in the quantitative variables and the association between them. These were regarded significant whenever P < 0.05.

Male patients had larger MITD and MWFH than females (P < 0.05). However, the EI lacked significant sexual variances (P = 0.051). As age increased, the mean EI also significantly increased, although, it did not exceed 0.3; the internationally recognised diagnostic cutoff value. The EI and MWFH showed a weak positive relationship with age, whereas the MITD and age had a weak negative association (P < 0.05). Both EI and MITD had a positive correlation with MWFH (P < 0.05).

The normative EI values established in this study provide reliable references than will aid clinicians to accurately diagnose and monitor patients with ventriculomegaly associated with normal pressure hydrocephalus and neurodegenerative disorders, ensuring more effective management.