A combined approach for the diagnosis of orbital disease. Computed tomography and standardized A-scan echography.

Twenty patients with orbital disease were studied by both computed tomography (CT scan) and standardized A-scan echography (ultrasonography). The CT scan was distinctly abnormal in 15 cases: 11/11 tumors were identified; a large wooden foreign body was identified; and nonspecific abnormal radiodensities were shown in three additional casses. Standardized A-scan echography, however, was capable of demonstrating the abnormality in all 20: in nine orbital tumors, a preoperative histologic diagnosis was attempted and proven accurate in all nine (in two no histologic disgnosis was attempted); and nontumor soft tissue abnormalities were equally readily classified. The overall diagnostic capability, therefore, in our series is 19/20 with a tissue diagnosis achieved on echographic bases in 17/20. (One case is excluded from this analysis as unexplained unilateral papilledema has been the only abnormality found and orbital abnormalities per se have not been proven.) We believe the roles of these two valuable diagnostic modalities to be complementary, not mutually exclusive, and conclude thet this combined radiologic and echographic approach to orbital abnormalities is essential to the proper evaluation of orbital disease.