ArticleBMC medical imaging2026
Age- and sex-specific reference values of Evans' Index and cranial dimensions on brain CT in a south-eastern Nigerian hospital population.
Article in BMC medical imaging, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
3 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundEvans' Index (EI) is a widely used linear radiological measure of ventricular size on computed tomography (CT) and magnetic resonance imaging. Despite the increasing use of volumetric neuroimaging techniques, EI remains a practical and commonly applied marker of ventricular enlargement in routine clinical practice. However, age- and sex-specific hospital-based reference values are limited in sub-Saharan Africa, where population-specific data are essential for accurate interpretation. This study aimed to establish age- and sex-specific hospital-based reference values for Evans' Index and cranial dimensions in a south-eastern Nigerian population using CT scans reported as normal despite clinical indications.
methodsThis retrospective cross-sectional study analysed 676 normal non-contrast cranial CT scans. Maximum anterior horn diameter (MAHD) and maximum internal cranial diameter (MICD) were measured at the level of the frontal horns, and EI was calculated as MAHD/MICD. Results from the non-normally distributed data were presented as median with quartile ranges (Q1-Q3) and percentile-based reference ranges (2.5th-97.5th percentiles). Associations with age and sex were assessed using non-parametric tests, and measurement reproducibility was evaluated using intraclass correlation coefficient analysis.
resultsOf the 676 participants, 268 (39.6%) were male and 408 (60.4%) were female. The overall median Evans' Index (EI) was 0.28 (Q1-Q3: 0.25-0.30), with a 95% reference range of 0.22-0.32. Females had significantly higher median EI (0.29 vs. 0.26) and larger MAHD compared with males, whereas males had significantly larger MICD (all p < 0.001, Mann-Whitney U test). EI demonstrated a strong positive correlation with age (Spearman's ρ = 0.746; p < 0.001), and multivariable regression analysis confirmed age as an independent predictor of EI. Significant differences in EI, MAHD, and MICD were observed across age groups (Kruskal-Wallis p < 0.001 for all). Median EI increased progressively across age categories (0.24 in 1-18 years, 0.26 in 19-50 years, 0.29 in 51-80 years, and 0.30 in ≥ 81 years), with corresponding increases in MAHD and a modest decline in MICD in older age groups.
conclusionsEvans' Index and cranial dimensions in south-eastern Nigeria vary significantly by age and sex. These hospital-based reference values are consistent with commonly used EI thresholds (≥ 0.30 for ventriculomegaly) while emphasising the need for age- and sex-stratified interpretation in clinical practice. These hospital-based reference values are derived from radiologically normal CT scans obtained during clinically indicated imaging and may not fully represent community-based healthy populations.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.