An Adaptive Inverse Image Construction Method for Contrast 3D Echocardiography

Contrast 3D echocardiography (C3DE) enhances the visual quality of ultrasound images in comparison with conventional 3D echocardiography (3DE). Though the image quality in C3DE is perceived to be improved for visual analysis, but it actually deteriorates for the purpose of automatic or semi-automatic analysis due to high speckle noise and intensity in homogeneity. Therefore, the left ventricle (LV) endocardial feature extraction and segmentation from C3DE images remains a challenging problem. To overcome this challenge, this work proposes a simple adaptive method to invert the appearance of C3DE image. In this inverted appearance, the LV cavity appears dark while the myocardium appears bright similar to 3DE image. Moreover, the resulting inverted image has high contrast and low noise appearance, yielding strong LV endocardium boundary and facilitating feature extraction for segmentation. The proposed method inverts the C3DE image by using a threshold that is determined automatically through image histogram analysis. Subsequently, the inverted image information is utilized in an edge-driven LV feature extraction and segmentation method. The segmentation results of LV boundary delineation are compared to manual LV boundary delineation and a good match is observed.