Atrium Of The Lateral Ventricle In A Posterior View Of The Ventricles

Description

Atrium (trigone) of the lateral ventricle occupies the posterior expansion where the ventricular body widens before giving rise to the occipital horn posteriorly and the temporal (inferior) horn anteroinferiorly. From this posterior viewpoint, the atrium sits inferior to the splenium of the corpus callosum and medial to the surrounding parietal and occipital white matter, with the paired lateral ventricles separated across the midline by the posterior third ventricle region. The choroid plexus is expected along the medial wall of the atrium, continuous with the glomus choroideum, a common calcification site on CT that can be mistaken for hemorrhage if its location is not recognized. Horn branching is the focus. Clinically, the atrium is a practical landmark in hydrocephalus and intraventricular hemorrhage because atrial enlargement reflects posterior ventricular dilation and helps explain symptoms from adjacent optic radiations, which sweep lateral to the trigone toward the calcarine cortex. Neurosurgeons also reference the trigone when planning trajectories for ventricular catheter placement or approaches to atrial lesions such as meningioma, ependymoma, or choroid plexus papilloma, where a few millimeters determine whether you traverse optic radiations or parietal association fibers. Posterior orientation clarifies laterality and makes the transition from ventricular body to occipital horn easier to teach than in an isolated horn view. Neuroanatomy and neuroradiology courses can pair this illustration with MR ventricular anatomy, while neurosurgical texts can use it to annotate atrial landmarks and safe corridors to the trigone. Anatomical accuracy verified by SciePro's Medical Advisory Board.