Dear Ged,
Thanks for the reply.

I was using Absolute threshold of thresholding as 0.1. I was also using the implicit mask and was not using the explicit mask.Also, i was using the Avg152T1.nii image in the canonical directory of the SPM as my image to overlay my result. I will look at the documentation of Imcalc() and try to make the average template of my spatially normalised bias corrected images which i got during the segmentation process. 
I will try your suggestions and also try to make a tighter mask.

Thanks
Tanmay