Investigation of the imaging diagnosis on the ophthalmic orbital diseases

Ultrasonographic examination, X-ray computerized tomography (CT) and magnetic resonance imaging (MRI) were performed on orbital diseases. Ultrasonographic examination was a simple, rapid and harmless noninvasive precedure as a diagnostic tool for evaluation of soft tissues. Echography was not more precise than X-ray CT and MRI scan in orbital diagnosis of the localization, size and well-defined outline of the lesion, relating to the peri- and retroorbital organs, however, was useful for screening study of an orbital lesion. B-mode of orbital tumors was effective for the ultrasonic diagnosis and classification according to four types; solid, cystic, angiomatous and infiltrative patterns. B-scan study of intraorbital inflammatory pseudo tumor could provide a differential diagnosis between inflammatory edema and an inflammatory mass lesion. Echographic pictures of dural arterio-venous fistula disclosed the vascular dilatation of superior ophthalmic vein and those of Basedow's disease with thickening of extraocular muscles. X-ray CT revealed intraorbital and intraocular disease, the globes and its immediate surrounding tissue (optic nerve, extraocular muscle, etc.) and bony orbital walls as the same slice of film. X-ray CT pictures of a coronal section, the contrast enhancement, calcification and destruction of the bone were helpful for diagnosis. However, the displays of disorders near the bone were ill-defined because of an artifact induced by high X-ray absorptive power of the bone. MRI was an equipment for superior contrast resolution, with provided a tomography of any section, without artifacts of the bone, and was the superior technique for displaying a vascular lesion. MRI of orbital disease was effective for reconstructing the spatial correlations between the lesion and its surounding tissues. MRI, however, provided no information of the skeleton, being not available for subjects with a magnetic substance. (author)