Comparison of ultrasonography, computerized tomography (EMI scan), and radiographic techniques in evaluation of exophthalmos.

A series of 342 consecutive patients with unilateral exophthalmos of confirmed etiology have been studied with a combination of clinical investigative techniques. High resolution B-scan ultrasonography and computerized tomography proved to be the most valuable tests for detecting orbital tumors and inflammatory conditions. Ultrasonography demonstrated primary orbital tumors but failed to show intracranial and some secondary tumors. Computerized tomography demonstrated primary, secondary, and intracranial tumors but not cystic masses. Inflammatory conditions such as Graves' disease and pseudotumor were characterized by ultrasonography also, while computerized tomography was not reliable for this. Correct diagnosis of orbital abnormalities in this series was 82% with ultrasonography and 72% with computerized tomography. Combined accuracy of these two complementary tests was 97% for tumor diagnosis. Conventional radiography and polytomography revealed secondary bony changes but not primary orbital tumors and inflammation. Orbital venography and arteriography had a low yield with tumors but were essential for demonstrating arteriovenous abnormalities. Orbital diagnosis has been improved significantly with the two newer techniques of ultrasonography and computerized tomography.