Enhanced resolution of pituitary fossa by three-dimensional fat-suppressed gradient-echo magnetic resonance: before and after gadolinium enhancement.

Abstract

In imaging small anatomical parts such as the pituitary fossa, thin sections enhance the spatial resolution. Gradient recalled images (GRASS) using three-dimensional volume data produce ultrathin contiguous sections with a high signal-to-noise ratio. In this study, conventional spin-echo magnetic resonance images (MRIs) of the pituitary fossa were compared to three-dimensional gradient recalled MRI in 5 volunteers and 10 patients suspected of having pituitary gland abnormalities. Utility of fat suppression was also assessed, along with gadolinium enhancement. Conventional spin-echo and three-dimensional spoiled GRASS images, three-dimensional spoiled GRASS images without and with fat suppression (Group II), and three-dimensional spoiled GRASS images with fat suppression before and after gadolinium enhancement were compared. Three-dimensional spoiled GRASS images provided better delineation of the pituitary fossa structures. There was differential enhancement between the normal gland and pituitary tumors. The fat suppression technique following gadolinium administration helped separate the high signal of tumor from the high signal of the clivus marrow. In conclusion, T1-weighted three dimensional gradient-echo images with fat suppression following gadolinium enhancement appear promising in evaluation.