Diffusion-Weighted Imaging and Post-contrast Enhancement in Differentiating Optic Neuritis and Non-arteritic Anterior Optic Neuropathy

ABSTRACT

Non-arteritic anterior ischaemic optic neuropathy (NAION) and optic neuritis (ON) may be difficult to distinguish early in their disease courses. Our goal was to determine if specific magnetic resonance imaging characteristics differentiate acute NAION from ON. Neuroradiologists, masked to diagnosis, reviewed the diffusion-weighted imaging (DWI) and post-contrast enhancement (PCE) characteristics of the optic nerve in 140 eyes. PCE and DWI signals of the optic disc alone did not discriminate between NAION and ON. After taking age and sex into consideration, only DWI and PCE of the intraorbital segment of the optic nerve differentiated the two, with ON having the increased likelihood of these findings. Isolated PCE without DWI signal at the optic disc, however, was 100% specific for NAION. This may be the most specific way to radiographically differentiate between NAION and ON in the acute setting.

KEYWORDS:

• Diffusion-weighted imaging
• magnetic resonanceimaging
• non-arteriticanterior ischaemic optic neuropathy
• optic neuritis
• post-contrast enhancement

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.

Funding

This work was supported in part by the National Institutes of Health (P30EY010608 [UTHealth]), Research to Prevent Blindness (Challenge Grant [UTHealth]), and the Hermann Eye Fund (UTHealth). No authors declare any conflicts of interest.

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Additional information

Funding

This work was supported in part by the National Institutes of Health (P30EY010608 [UTHealth]), Research to Prevent Blindness (Challenge Grant [UTHealth]), and the Hermann Eye Fund (UTHealth). No authors declare any conflicts of interest.