For the myocardium processing

Hi everyone! Wish you have a good day! I am trying to find the contour and edema of the myocardium automatically, and by using the functions (imfindcircles,contour...), and testing the area of the Blob, I can get these results:

As we can see, the inner (red) contour overlaps the edema, and the result doesn't shows well. As for the inner and outer (blue) contours, they need to be deleted the sharp-edged corners and becomes smooth. The idealistic result should be like (c) of the second image.

Could you please tell me how to improve my results? Thanks a lot! :-)