PITUITARY-GLAND ENLARGEMENT SECONDARY TO DURAL ARTERIOVENOUS-FISTULA IN THE CAVERNOUS SINUS - APPEARANCE AT MR-IMAGING

PURPOSE: To evaluate pituitary gland size in cases of dural arterioven ous (AV) fistula in the cavernous sinus and to correlate the size with the degree of AV fistula. MATERIALS AND METHODS: Magnetic resonance i mages in 21 patients with angiographically proved dural AV fistula of the cavernous sinus were retrospectively reviewed. In four patients, f indings obtained before and after embolization therapy were compared. RESULTS: The 21 patients were divided into group 1 (severe AV fistula) and group 2 (moderate or mild AV fistula). The superior contour of th e pituitary gland was convex or flat in group 1 and flat or concave in group 2. The mean height of the pituitary gland was 9.4 mm +/- 1.5 (s tandard deviation) in group 1 and 6.7 mm +/- 1.2 in group 2 (P = .0002 ). After embolization therapy, pituitary gland height decreased and si gnal intensity voids improved in the four patients and no AV fistula w as observed in three. CONCLUSION: In cases of severe dural AV fistula in the cavernous sinus, the pituitary gland is enlarged, which should not be misdiagnosed as pathologic.