Optic nerve atrophy and retinal nerve fibre layer thinning following optic neuritis: evidence that axonal loss is a substrate of MRI-detected atrophy.

Magnetic resonance imaging (MRI) measures of brain atrophy are often considered to be a marker of axonal loss in multiple sclerosis (MS) but evidence is limited. Optic neuritis is a common manifestation of MS and results in optic nerve atrophy. Retinal nerve fibre layer (RNFL) imaging is a non-invasive way of detecting axonal loss following optic neuritis.

Optic nerve diffusion tensor imaging in optic neuritis.

Diffusion tensor magnetic resonance imaging (DT-MRI) provides in vivo information about the pathology of multiple sclerosis lesions. Increases in mean diffusivity (MD) and reductions in fractional anisotropy (FA) have been found and may represent axonal disruption. The optic nerve is an ideal structure for study by DT-MRI but previous clinical studies did not obtain the full diffusion tensor necessary to calculate MD and FA.

Imaging characteristics of primary cranial Ewing sarcoma.

Background: Ewing sarcoma accounts for 10-15% of all childhood malignant bone tumours and is second in prevalence to osteosarcoma. The skull bones are an unusual site of origin of primary Ewing sarcoma in children. Previous reports concentrate on the neurosurgical aspects and relatively good outcome compared to other bone tumours of the calvarium.