Radiologic pitfalls in neuro‐ophthalmology

Abstract

Abstract Purpose: Although standard neuro‐imaging methods have a major contribution to appropriate diagnosis in neuro‐ophthalmology, they do not represent «one size fits all» procedures. Structural lesions can sometimes escape detection, mainly because of suboptimal clinical information for the radiologists. Methods: This presentation will illustrate some common errors in prescription or interpretation of neuroimaging in neuro‐ophthalmology. Results: Several protocols are used by each center depending on the explored pathology (multiple sclerosis, aneurysms, carotid dissection) or the anatomical location of the condition (orbit, cavernous sinus, sella, etc). When an MRI is indicated, application of intravenous contrast is not routine, especially if the expected lesion is supposed to be large enough. Contrast injection may be mandatory for detection of small lesions, even though this increases study acquisition time and is more expensive. Fat suppression is critical for detection of small lesions located in areas containing fat, such as orbits, or neck. Multiple, thin, coronal images are very useful for visualization of the chiasm, cavernous sinus and the possible sourounding compressive structures (i.e. pituitary adenoma, small meningioma). Specially dedicated sequences explore the white matter in multiple sclerosis or can find abnormalities in early ischemic events, while standard MRI can overlook these lesions. One can not perform all these protocols in every patient, the choice being dependent on the clinical information, the technical availability and the local expertise. Conclusions: Appropriate neuro‐imaging can result only from clear, informative clinical indications about symptoms with localizing value, whenever possible.