MRI of idiopathic orbital inflammatory syndrome using fat saturation and Gd-DTPA

Idiopathic orbital inflammatory syndrome encompasses a group of inflammatory conditions for which no systemic or local cause can be found, and is commonly referred to as orbital pseudotumour. On conventional MRI sequences subtle areas of inflammation or enhancing tissue can easily be masked by the high signal intensity of orbital fat and involvement of the fat itself may not be appreciated. We describe the MRI features of three patients with idiopathic orbital inflammation using frequency-selective fat saturation and Gd-DTPA.