The purpose of our educational exposition is to: Describe the anatomy of the optic nerve (ON) Illustrate the main findings and differential diagnosis of ON pathologies on computed tomography (CT) and on magnetic resonance imaging (MRI). Discuss the main etiologies: congenital, inflammatory/ infectious, neoplastic, vascular and others, based on 10 years of experience of our Neuroradiology service.

Along with clinical and ophthalmoscopic evaluation, imaging, especially magnetic resonance imaging, plays an important role in the thorough evaluation of optic nerve (ON) and the entire visual pathway [1]. The knowledge of this detailed anatomy and its main pathologies is essential for the patient's highly accurate diagnosis. The ON (the second cranial nerve) is an extension of the central nervous system (CNS) axons, thus, it’s myelinated by oligodendrocytes. It originates from the retina,...

Differential diagnosis of ON pathology can be broadly divided into congenital, inflammatory/infectious, neoplastic, vascular and others. In the following section, we will be exploring the main pathologies related to each one of these topics and their main imaging features. 1.CONGENITAL: 1.1 Optic nerve aplasia/hypoplasia ON aplasia is a rare, congenital developmental anomaly, comprising of the absence of ON, central retinal vessels and ganglion cells while the ON hypoplasia is characterized...

The differential diagnosis for optic nerve pathologies is broad. Clinical information, understanding of the main imaging features, and knowledge in imaging methods and protocols can help radiologists to reach the most accurate diagnosis. After all, a trained radiologist’s eye may improve patient’s chances of seeing and believing.

Matheus Dorigatti Soldatelli, MD, Department of Radiology, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil; md.soldatelli@gmail.com Juliana Ávila Duarte, MD PhD, Department of Radiology, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil; juduarte@hcpa.edu.br

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