Ventricular enlargement in normal aging frequently forces the radiological diagnosis of hydrocephalus, but the reliability of Evans' index as a radiological marker of abnormal ventricular enlargement (values > 0.30) during aging is not assessed. Here we analyze ventricular size during aging and the reliability of Evans' index as a radiological marker of abnormal ventricular enlargement. We calculated Evans' index in the axial Computed Tomography scans of 1221 consecutive individuals (aged 45-101 years) from an emergency department. Stratified analysis of one-year cohorts showed that the mean Evans' index value per class was invariably < 0.30. Roughly one out five Computed Tomography scans was associated with Evans' index values > 0.30 and Evans' index values increased with age. The risk of having an Evans' index value > 0.30 increased by 7.8% per year of age (p < 0.001) and males were at 83.9% greater risk than females (p < 0.001). Overall, this study shows that normal aging enlarges the ventricular system, but never causes abnormal ventricular enlargement. Evans' index values > 0.30 should reflect an underlying neurological condition in every individual.
Keywords: Evans’ index; Gerotarget; aging; brain; enlargement; ventricular system.