Diffusion restriction of the optic nerve in patients with acute visual deficit.
PURPOSE
Diffusion magnetic resonance imaging (MRI) is commonly used in acute stroke, but not considered diagnostic in ischemic optic neuropathy. This study evaluates the presence of diffusion restriction in patients with acute visual loss by analyzing diffusion-weighted images (DWI).


MATERIALS AND METHODS
A retrospective study of all patients who clinically presented with acute visual loss and who underwent MRI with DWI between January 2011 and May 2012 were evaluated. Patients with suspected brainstem ischemia were used as a control group. Two neuroradiologists evaluated the DWI for the presence of diffusion restriction within the optic nerve.


RESULTS
In all, 34 patients with acute visual deficit and 32 controls were evaluated. In all five cases of acute optic ischemia, diffusion restriction with reduced apparent diffusion coefficient was present. In 2/25 patients with clinically defined optic neuritis, a diffusion restriction was present. No diffusion restriction was seen in the control cases or in cases with other causes for an acute visual deficit.


CONCLUSION
DWI can identify ischemic lesions of the optic nerve. As in acute multiple sclerosis lesions, optic neuritis can also present in rare circumstances with diffusion restriction and can therefore not be ruled out solely by DWI MRI.
['Bender|Benjamin|B|', 'Heine|Christian|C|', 'Danz|Sören|S|', 'Bischof|Felix|F|', 'Reimann|Katrin|K|', 'Bender|Miriam|M|', 'Nägele|Thomas|T|', 'Ernemann|Ulrike|U|', 'Korn|Andreas|A|']
D000208:Acute Disease D000328:Adult D000368:Aged D000369:Aged, 80 and over D004058:Diffusion D056324:Diffusion Tensor Imaging D005260:Female D006801:Humans D008297:Male D008875:Middle Aged D009900:Optic Nerve D018917:Optic Neuropathy, Ischemic D015203:Reproducibility of Results D012680:Sensitivity and Specificity D014786:Vision Disorders D066127:White Matter
optic nerve MRI DWI optic ischemia optic neuritis