Neuroimaging in ophthalmology

Abstract

In the past three decades, there have been countless advances in imaging modalities that have revolutionized evaluation, management, and treatment of neuro-ophthalmic disorders. Non-invasive approaches for early detection and monitoring of treatments have decreased morbidity and mortality. Understanding of basic methods of imaging techniques and choice of imaging modalities in cases encountered in neuro-ophthalmology clinic is critical for proper evaluation of patients. Two main imaging modalities that are often used are computed tomography (CT) and magnetic resonance imaging (MRI). However, variations of these modalities and appropriate location of imaging must be considered in each clinical scenario. In this article, we review and summarize the best neuroimaging studies for specific neuro-ophthalmic indications and the diagnostic radiographic findings for important clinical entities.

Prevalence of significant pathology on MRI of brain and orbits in patients presenting with visual disturbance

“…Posterior circulation infarction can present with visual disturbance due to interruption of the visual pathway secondary to thalamic infarction, occipital lobe (Figure 4(a-c)) or midbrain infarction, for example. MRI is very sensitive and specific in the diagnosis of acute infarction using a diffusion weighted imaging sequence (DWI), 1,2 with characteristic changes remaining thereafter.…”

“…Magnetic resonance imaging (MRI) is the imaging modality of choice owing to superior soft tissue resolution versus computed 1 Royal Victoria Eye and Ear Hospital, Dublin 2, Ireland 2 St. Vincent's University Hospital, Dublin 4, Ireland tomography (CT). 1,2 MRI has also been shown to be more sensitive in the detection of orbital and periorbital structural abnormalities than CT. CT is superior in cases of trauma or suspected bony pathology.…”

Imaging of the Primary Visual Pathway based on Visual Deficits

“…CT can evaluate the bony anatomy of the orbits and skull base, identify calcifications, delineate fractures, and highlight radiopaque foreign bodies. [ 4 ] CT is typically performed with thin section axial spiral acquisition (0.6–1.25 mm) with the patient instructed to focus on a stationary object to limit radiation to the lens; subsequently, multiplanar reformations can be generated. Intravenous contrast is generally not required unless assessing for inflammatory or neoplastic processes.…”

“…Many of the ocular globe pathologies which may lead to blindness such as CMV-induced retinitis, endophthalmitis, and retinal detachment can be diagnosed by ophthalmologic examination and therefore will not be discussed in this article. [ 4 ] Imaging has the potential to aid clinicians in disease processes which extend into the deeper soft tissues. For example, radiologists can readily differentiate between superficial infection (pre-septal cellulitis) versus deeper infections beyond the orbital septum (post-septal cellulitis).…”

MRI of acquired Brown syndrome: a report of two cases

“…Although CT imaging can be valuable for the diagnosis of Brown syndrome, it has largely been replaced by magnetic resonance imaging (MRI) because of the superior soft tissue resolution offered by the technique [11] , [12] . For this reason, MRI is superior to CT for most ophthalmologic conditions, especially pathologies that involve extraocular muscles [13] , [14] , [15] , [16] , [17] , [18] .…”