Introduction: Several histopathological and gross changes are seen in human brain as age increases, causing enlargement of the lateral ventricles. Morphometric measurement and ventricular size of lateral ventricle is of trivial importance to identify certain changes and correlate it with clinical significance. This study is designed to provide a normal data of Evans Index of lateral ventricle of brain and its association between both the genders and its correlation with different age group of North Indian Population.

Materials and methods: This study was carried out in the Department of Anatomy & Department of Radiodiagnosis, S.N Medical College, Agra, U.P. In this prospective study, Computed Tomography Scans of 200 patients between the age 18 – 75 years (120 Males and 80 Females) were done and measurements of lateral ventricle of Brain and were analyzed statistically.

Results: The overall mean value of Evans Index is 0.23 ± 0.02. Evans Index in males is 0.23 ±

0.02 and mean Evans Index in females is 0.22 ± 0.01, the difference being statistically significant between both the genders as p = 0.0001* (p ≤ 0.05).

Conclusions: Evans Index is a widely and most commonly used linear measurement for the determination of ventricular dilation which is helpful in diagnosis of neurological conditions (e.g.schizophrenia, bipolar disorder and Non Pressure Hydrocephalus). If the Evans Index ranges from 0.25 to 0.30 represented early ventricular enlargement and if the Evans Index value is more than 0.30, it suggests Hydrocephalus.

Keywords: Lateral Ventricle, Brain, Morphometry, Ventricular system, CT, Evans Index