In this paper, a magnetic resonance imaging (MRI) based image segmentation technique has been proposed which uses magnetic resonance parametric information model for breast tumor segmentation. The methodology has been developed on two dimensional MRI data set. With the help of proposed technique, the breast tumor tissues can be segmented in 6-8 minutes with more precision & reproducibility than the manual (supervised) segmentation which takes more than two hours to segment breast tumor tissues. Thus, the proposed semi-automatic (un-supervised) technique can be applied to the prospective application of MRI data which will improve the procedure for diagnosing the breast tumor for two dimensional hallucinations for surgery purposes.