Heart disease is the most prevalent kind of disease even among the young people, which has logged the maximum number of lives so far. Earlier it was a disease which claimed people above 50 years of age, but as of now it has it is consuming even the lives of small children with congenital heart diseases. This part of the work also has focused on the cardiac MRI images related to congenital disorders among children in the age group of 2 years to 17 years of age. Medical image enhancement technique is the need of the hour for quick and accurate diagnosis of heart ailments and for medical intervention to take over accordingly. In this paper we focused more on the morphological operations in continuation of our research work in our earlier paper. Different morphological operations were tried over the pre-processed images and the experimental results showed that the opening operation gave a least error measure of all. Various error estimates over these operations were taken, like MSE, RMSE, MAE, etc. were calculated for all MR images and was found the opening operation had a less error compared to other operations, which implies that opened images have more clarity than the other operations.