1. A method of detecting centerline of a vessel, the method comprising: acquiring a 3D image volume; initializing a centerline; initializing a Kalman filter; predicting a next center point using the Kalman filter; checking validity of the prediction; performing template matching for estimating measurement error; updating the Kalman filter based on the template matching; and repeating the steps of predicting, checking, performing and updating for a predetermined number of times.