Automatic Liver segmentation Using Vector Field Convolution and Artificial Neural Network in MRI Images

Accurate liver segmentation on Magnetic Resonance Images (MRI) is a challenging task especially at sites where surrounding tissues such as spleen and kidney have densities similar to that of the liver and lesions reside at the liver edges. The first and essential step for computer aided diagnosis (CAD) is the automatic liver segmentation that is still an open problem. Extensive research has been performed for liver segmentation; however it is still challenging to distinguish which algorithm produces more precise segmentation results to various medical images. Accordingly, in this paper, we have presented a new automatic system for liver segmentation in abdominal MRI images. Our method extracts liver regions based on several successive steps. The preprocessing stage is applied for image enhancement such as edge preserved and noise reduction. The proposed algorithm for liver segmentation is a combined algorithm which utilizes a contour algorithm with a Vector Field Convolution (VFC) field as its external force and perceptron neural network. By convolving the edge map generated from the image with the user-defined vector field kernel, VFC is calculated. We use trained neural networks to extract some features from liver region. The extracted features are used to find initial point for starting VFC algorithm. This system was applied to a series of test images to extract liver region. Experimental results showed the promise of the proposed algorithm.