Computerized axial tomography in the detection of orbital space-occupying lesions.

Of 41 patients we examined for a suspected primary orbital tumor, 25 patients had evidence of a lesion either histologically, angiographically, or surgically. We examined nine of the 25 patients by means of an EMI-Scanner and 16 by a fine matrix addition (160 times 160 cells), and compared these results to those we received by axial tomography, orbital venography, and B-scan ultrasound. We also compared the absorption values of the recorded tumors. The EMI-Scanner had a diagnostic accuracy of 84%; orbital venography, 84%; axial hypocycloidal tomography, 71%; and ultrasound, 76%. The fine matrix scanner gave a preoperative diagnostic rate of 93% and defined optic nerve abnormalities accurately. However, EMI, scanning should complement existing noninvasive procedures and orbital venography.