Nuclear magnetic resonance tomography of the orbit at 3.4 MHz.

The significantly different signals from the various structures within the orbit suggest that NMR tomography will prove to be a valuable method for the diagnosis of both ocular and orbital disease. The resolution of the technique is initially illustrated by the demonstration of the signal patterns from the normal globe and orbit. The characteristic features of some pathological conditions, including vitreous haemorrhage and retinal detachment, are then shown. The value and limitations of the technique in differentiating conditions such as choroidal haemorrhage from malignant melanoma, and intra-orbital lymphoma from pseudo-tumour, are illustrated and discussed. The absence of artefact from bone, synthetic lens implants and non-ferromagnetic metallic foreign bodies is stressed.