MR imaging of posterior pituitary in patients with pituitary adenoma

Abstract

Objective To analyze the occurrence and location of posterior pituitary bright spot (PPBS) and its influence factors by analyzing the magnetic resonance T1-weighted imaging (T1WI) in patients with pituitary adenoma. Methods One hundred and twenty-three patients with pituitary adenoma, admitted to our hospital from September 2012 to September 2014, were collected in our study. All patients were performed T1WI and T2WI sagittal, coronal and axial scan and enhanced scan at SE sequence before operation. The occurrence and location of PPBS of the pituitary gland were observed; the clinical data of these patients from PPBS-visible group and PPBS-non-visible group were analyzed and compared. Results Of the 123 patients, the PPBS-visible group included 98 patients (79.7%) and the PPBS-non-visible group included 25 patients (20.3%). The adenoma shapes were classified into hourglass-type (n=43), barrel-type (n=63) and wedge-type (n=17). The occurrence rate of PPBS in barrel-type patients was significantly lower than hourglass-type patients (P<0.05); the signal intensity ratio of PPBS and pons in barrel-type patients and wedge-type patients was significantly higher than that in the hourglass-type patients (P<0.05). Adenoma volume and height of the PPBS-visible group was significantly smaller than those in the PPBS-non-visible group (P<0.05). The distribution of different adenoma types was significantly different between patients from PPBS-visible group and PPBS-non-visible group (P<0.05). Conclusion The posterior lobe of pituitary could be displayed satisfactorily at T1WI, and appearance of PPBS is related to the morphology, volume and height of pituitary adenoma. Key words: Pituitary adenoma; Pituitary; Magnetic resonance imaging; Posterior pituitary bright spot