Abstract

Incidental findings on brain MR and variation of the circle of Willis (CoW) are relatively common among the general population. Ethnic differences have been described before, but few studies have explored the prevalence of incidental intracranial cerebrovascular findings and CoW variants in the setting of a single multi-ethnic cohort. The purpose of this investigation is to describe both incidental cerebrovascular findings and the morphology of the CoW on high-resolution 3T time-of-flight MR angiography (ToF MRA) in a UK tri-ethnic population-based cohort and to present updated prevalence estimates and morphologic reference values.