Posterior Pituitary Bright Spot Normal Dimensions on MRI

Aim: To assess the measurements of posterior pituitary bright spot on MRI in Khyber Pakhtunkhwa Methods: The study was done in RMI, Peshawar. Duration is January, 2016 to February, 2019. 78 patients with normal pituitary MRI studies were selected for study. MRI without contrast was done along cranio caudal and antero posterior axis on sagital T1WI. Three cases of ectopic posterior pituitary were also included. Results: Dimensions were taken in antero posterior and cranio caudal axis on sagittal T1WI. Dimension of PPBS was 1.8-8.6mm in cranio caudal axis and 0.8-6mm in antero posteriorly. Mean +/- SD of cranio caudal measurement was 5.09 +/- 1.28mm and of antero posteriorly 2.42 +/- 0.9mm. Pearsons analysis showed direct correlation i.e. as value of cranio caudal diameter increased, the antero posteriorly also increased. Conclusion: PPBS was identified in 100% of normal pituitary glands. Mean PPBS size normally ranged from 1.8 to 8mm i.e. mean +/- SD was 5.09 +/- 1.28mm craniocaudally. There is a direct correlation in cranio caudal and antero posterior dimensions of PPBS.