Radiology, Vol 180, 779-784, Copyright © 1991 by Radiological Society of North America
Pituitary adenoma: correlation of half-dose gadolinium-enhanced MR imaging with surgical findings in 26 patients
PC Davis, KA Gokhale, GJ Joseph, SB Peterman, DA Adams, GT Tindall, PA Hudgins and JC Hoffman Jr
Division of Neuroradiology, Emory University School of Medicine, Atlanta, GA 30322.
Sellar magnetic resonance imaging studies obtained with half doses of
gadopentetate dimeglumine (0.05 mmol/kg) were prospectively interpreted and
retrospectively rated in 26 patients who subsequently underwent
transsphenoidal sellar surgery for suspected pituitary adenoma. Studies
included a sagittal scout view followed by a non-contrast-material-
enhanced, an immediate postcontrast, and a delayed postcontrast T1-
weighted image (obtained at 1.0 or 1.5 T). Ten of 11 confirmed
microadenomas were identified prospectively; all were identifiable in
retrospect. Macroadenomas (12 cases) were well demonstrated. The high
signal intensity of the posterior pituitary and of intrasellar hemorrhage
was obscured on postcontrast studies. Delayed images proved unnecessary.
This prospective evaluation suggests that a half-dose study is comparable
to retrospective studies in which full-dose techniques were used for
detection of micro- and macroadenomas. Imaging times are reasonably short,
and cost of contrast material is potentially reduced. Confirmation with
larger studies is required, and careful endocrinologic and clinical
follow-up of nonsurgical patients is necessary.
