Magnetic resonance imaging and computed tomography of the orbit in Wegener's granulomatosis

Of a total of 121 patients with histological proven Wegener's Granulomatosis, orbital involvement occurred in 12 cases. Eight of them underwent magnetic resonance imaging (MRI) of the head and brain, in 2 cases computed tomography (CT) was additionally performed. With MRI orbital granulomas had a low signal intensity in T₁- and T₂-weighted spin-echo sequences. After i.v. contrast medium administration an inhomogeneous enhancement was found. Because of the multiple imaging planes and high soft tissue contrast, orbital granulomas were better delineate with regard to the intraorbital muscles and the optic nerve using MRI than with CT. Osseous destruction and sclerosis of the orbital walls were demonstrated more effectively using CT. MRI and CT are thus complementary for diagnosing and staging, of orbital granulomas and periorbital involvement in Wegener's Granulomatosis.