Diagnostic value of MRI in pituitary stalk interruption syndrome

Objective To study characteristic findings and the diagnostic value of MRI in pituitary stalk interruption syndrome (PSIS). Methods Twenty-one patients with PSIS were included. Small field of view (FOV) MR1 scanning and clinic hormone detection were performed in all patients. Moreover, fluid attenuated inversion recovery (FLAIR)T,1 WI with fat-suppression sequence was performed in 8 cases. The appearance on FLAIR T1 WI and T2 WI were recorded. The shape of pituitary stalk and antehypophysis, and the signal intensity of posthypophysis were analyzed simultaneously. Results Growth hormone deficiency (GHD) was confirmed by clinic hormone detection in all 21 cases. The level of basal GH varied from 0. 03 μg,/L to 1.50 μg/L. The peak value under GH provocation was from 0. 13 μg/L to 4. 14 μg/L, and the GH was absolute default in all patients. Seventeen cases of them were combined pituitary hormone deficiency (CPHD), and 4 cases were isolated growth hormone deficiency (IGHD). The height of antepituitary was in the range from 1 mm to 3 mm, and the average value was (1.9±1.2) mm. Pituitary stalk was absent in 18 cases and showed as linear and discontinuous stalk in the other 3 cases. The high signal intensity was invisible in normal position in all cases, the high signal intensity spot in the region of infundibular recess of the third ventricle was shown in 19 cases, while it could not be found anywhere in 2 patients with diabetes insipidus. Conclusion PSIS often shows characteristic appearance on MRI, and a definite diagnosis can be made by using MRI combined with clinic hormone detection. Key words: Dwarfism, pituitary;  Magnetic resonance imaging