Ultrasonography and computer tomography in orbital diagnosis. With special reference to dysthyroid ophthalmopathy.

A report is given on a series of 162 patients referred for ultrasound examination (US, A-mode) due to orbital disease. 101 also had computerized tomography (CT, Emi scanner Mark I, 160 X 160 matrix, 8 mm sections), the results of which were emphasized in a recent publication (Gyldensted et al. 1977). The present approach is primarily clinical. With histopathological confirmation in only 40% of the cases, it is difficult to give exact values for diagnostic accuracy, but it appeared to be above 90% for CT, and close to this value for US (depending on, of course, how specified the diagnostic predictions were). Dysthyroid ophthalmopathy (DO, orbital Graves' disease, endocrine exophthalmos) was the most frequent cause of unilateral protrusion (24 cases). In some such cases "tumour-positive" CT scans represent a diagnostic pitfall, unless the examiner is familiar with the clinical features of DO. In the present series, for example, one of the DO cases had transcranial exploration of the orbit. The two--indeed valuable--non-invasive methods (CT and US) should be assessed in combination, and also combined with the classic clinical evaluation of the patient.