A Survey of the Presence of Infundibular Tilt of Normal Pituitary Gland in Adults through MRI(Magnetic Resonance Imaging)

Magnetic resonance imaging(MRI) in the coronal plane before and after contrast is currently considered to be the most specific and sensitive technique for imaging pituitary gland. However, because of the false negative results of this method in the detection of pituitary microadenomas and the importance of finding these microadenomas, infundibular deviation or tilt in MRI is used to support the existence of pituitary microadenomas. This study was performed to determine the frequency of this tilt as a normal variant in adult Iranian population with no pituitary disease and to establish a normal base to facilitate the assessment of pituitary gland in neuroendocrine diseases and the detection of microadenomas. This study was a cross-sectional observational prospective survey performed on coronal brain MRIs of 60 patients who had been examined for reasons other than pituitary disease in Hazrat – e – Rasoul Hospital from March until September 2004. The obtained data concerned sex, age, existence and type of infundibular tilt. 40% of the studied population had infundibular tilt of normal pituitary gland in MRI as a normal variation. This tilt was due to the lateral eccentricity of normal pituitary gland in relation to the midline of the brain in 26.7% of the above-mentioned cases and due to the eccentric insertion of pituitary stalk off the midline of the normal gland in the other 13.3%. There was no significant relationship between existence and type of infundibular tilt of normal pituitary gland in MRI and sex and age. There was no significant difference in the frequency of infundibular tilt between Iranian population with no pituitary disease and the American study group. Therefore, with respect to the high frequency of stalk deviation of normal pituitary gland in Iranian population, such displacement should not be used by itself to support the presence of pituitary microadenoma in MRI.