Figure 1 :(a) MRI T1 post-gadolinium image (sagittal view) demonstrating the "Snowman" sign of pituitary adenoma. (b) Six months after GK radiosurgery, MRI T1 post-gadolinium image (sagittal view) demonstrating that the "Snowman" sign of pituitary adenoma had disappeared and the volume of pituitary was 1.6×1.6×0.5 cm in size