Comparison of full- and half-dose gadolinium-DTPA: MR imaging of the normal sella.

PURPOSE This study compares sellar intensities in 17 patients without sellar pathology using half (0.05 mmol/kg, nine patients) and full-dose (0.1 mmol/kg, eight patients) gadopentetate dimeglumine (Gd-DTPA). METHODS Sellar MR studies of eight patients who received full and nine patients who received half-dose Gd-DTPA were compared, retrospectively. Sequences included pre-, immediate, and delayed postcontrast T1-weighted coronal images (1.5 T). Intensity measurements were obtained by two observers using a uniform region of interest. RESULTS Comparison of normalized intensities revealed no significant difference between intensities obtained from immediate half- and full-dose techniques for any of the tissues examined (Student's t test, P < .90). Delayed scans likewise demonstrated no significant intensity differences between full- and half-dose studies. CONCLUSION Our findings suggest that a 50% reduction in dosage of Gd-DTPA for sellar MR at 1.5 T results in no significant diminution in intensity of enhancement of the pituitary gland or adjacent tissues.