Magnetic resonance characterization of the ‘dot sign’ in colloid cysts of the third ventricle

Abstract

Purpose: To determine the incidence of the ‘dot sign’ in patients with colloid cysts of the third ventricle and to characterise its MRI appearances. Materials and Methods: Single institution retrospective analysis between January 2007 and October 2016 of all patients with either an imaging or imaging and histology-confirmed diagnosis of colloid cysts of the 3rd ventricle was undertaken. For all cases, MRI signal intensities of the cyst fluid component were graded by two independent radiologists relative to brain parenchyma. Presence of a dot, and if present, its size and relative position within the cyst were recorded. Signal intensities of the dot were then similarly assessed. Results: 37 c..