Background: Nowadays MRI examinations have been widely used in clinical applications for many diagnoses. The use of contrast agent in MRI improves lesion detection and characterization and causes more accurate diagnosis. Objectives: The aim of this study was comparing to optimal dose of Magnevist contrast agent in modified T1W SE (Spin Echo), T1W FSE (Fast Spin Echo) and T1W GRE (GRadient Echo) and effect of scan parameters of these sequences on the maximum SI of Magnevist contrast agent. Material and Method: This study was done on a phantom that was containing test tubes. These test tubes were filled with 30ml saline mixed with different doses of Magnevist contrast agent. In this study, some scan parameters of T1W pulse sequences were changed to achieve optimal parameters for maximum SI of contrast agent. In this study maximum signal intensity of each image was measured by ImageJ software. Results: The results of this study show that there are differences in maximum SI in different T1W pulse sequences with changing scan parameters. This study shows that 0.625 mmol/L of Magnevist has maximum SI in all of sequences. The maximum SI can be seen at GRE, SE and FSE sequences, respectively.Conclusion: Using routine and changed scan parameters, each pulse sequence reaches different maximum SI in specific concentration , which is highest in 2D SPGR (SPoiled GRadient) with flip angle = 75Ëš and least in T1W SE with TE (Time of Echo) = 40ms.