Combined Fat- and Water-Suppressed MR Imaging of Orbital Tumors

Coronal images through the orbits of a patient with an orbital apex meningioma. The sequences are T2-weighted SPIR (A), SPIR/FLAIR (B ), T1-weighted SPIR with contrast (C ), and STIR (D).

Images in the mid orbit (top row) show normal appearances on the STIR (top of D) and T2-weighted SPIR (top of A) images. The SPIR/FLAIR image (top of B) clearly shows increased signal in the optic nerve itself. Postcontrast T1-weighted SPIR (top of C) shows thickening of the optic nerve sheath because of meningioma en plaque. Images at the orbital apex (bottom row) demonstrate a mass lesion in the position of the optic nerve–sheath complex. The contrast between the lesion and surrounding tissues is greater on the SPIR/FLAIR image (bottom of B) than on the T2-weighted SPIR (bottom of A) or STIR (bottom of D) images. On the postcontrast T1-weighted SPIR image (bottom of C) the lesion shows inhomogeneous enhancement and is difficult to distinguish from adjacent enhancing extraocular muscles.

Axial images through the globe in a patient with a small melanotic melanoma with an associated retinal detachment. The SPIR/FLAIR sequence (A) shows the extent of the detachment more clearly than the T2-weighted SPIR (B ) and STIR images (C ), but does not reveal the tumor itself.

Coronal images through the orbit in a patient with an orbital apex meningioma. The extensive intracranial en plaque spread is shown well on the T1-weighted SPIR sequence with contrast (C ) and also can be appreciated on the T2-weighted SPIR (A) and STIR (D) images it is outlined by high-signal CSF. Although the meningeal thickening can be seen on the SPIR/FLAIR sequences (B ), its presence and extent were not appreciated by either of the radiologists who were reporting on this scan in isolation.