Atrial diverticula in severe hydrocephalus.

Area of Science:

• Neuroimaging
• Radiology
• Neuropathology

Background:

• Massive ventricular dilatation is a critical condition.
• It can lead to stretching and dehiscence of the fornix.
• This results in the formation of pial pulsion diverticula.

Purpose of the Study:

• To describe the imaging findings of pial pulsion diverticula.
• To differentiate these diverticula from other cystic lesions.
• To establish diagnostic criteria using computed tomography (CT).

Main Methods:

• Analysis of computed tomography (CT) scans in patients with massive ventricular dilatation.
• Identification and characterization of unilateral or bilateral pial pulsion diverticula.
• Correlation of imaging findings with anatomical structures.

Main Results:

• Pial pulsion diverticula present as subarachnoid cysts, potentially herniating into adjacent cisterns.
• Ten specific CT signs are identified to distinguish these diverticula from dilated fourth ventricles or suprapineal recesses.
• Key signs include atrial dilatation, medial atrial wall dehiscence, tentorial band abnormalities, and displacement of adjacent structures.

Conclusions:

• Pial pulsion diverticula are a distinct entity arising from massive ventricular dilatation.
• A comprehensive set of CT findings allows for accurate diagnosis and differentiation from other cystic lesions.
• Recognition of these imaging features is crucial for appropriate patient management.