Isolation of the myocardial scar from delayed enhancement cardiac magnetic resonance image (DEMRI) for a qualitative and quantitative assessment is of significant early diagnostic and accurate prognostic value for patients with ischemic heart diseases. To address the issue of the common error in the segmentation of the myocardial scar as a result of noise due to endocardial contours of the left ventricle, the threshold segmentation algorithm for myocardial scar based on the grey-level correction is proposed. In this algorithm, the grey-level correction of the myocardial region is first performed in the order of the following three steps: pixel labeling, influence calculation and grey updating. Then the threshold segmentation of the myocardial scar is conducted in combination with the OSTU algorithm. The experimental results indicate that the proposed method in the paper is better agreement with the results obtained with manual tracing by experience physicians compared to the previous myocardial scar segmentation algorithm, effectively preventing the error in the segmentation of the myocardial scar as a result of noise due to endocardial contours of the left ventricle.
