Aiming at solving the segmentation problem caused by the connection of lung nodule and vessel

a new adaptive bandwidth selection method based on EM is proposed and we apply it into nodule segmentation. Compared it to the method of bandwidth chosen based on statistical analysis rule or optimized rule

it has some advantages such as low time complexity and correct bandwidth in accord with a real problem.The vertical orientation vectors of vessels gradient was constructed as to normal distribution and the vertical orientation vectors of nodules gradient as uniform distribution

we modeled the nodule connected vessel

estimated model parameters by EM

and extracted bandwidth values in Mean-shift based on the weight of uniform distribution and bandwidth selection theorem. The proposed method was tested on synthetic data and the clinical chest CT volumes

and all the results were correct. The results revealed that the proposed method is successful in segmentation lung nodules connected vessel.