The present disclosure is directed to a planning and navigation method. The planning and method includes obtaining and rendering a plurality of images. The plurality of images are segmented to demarcate a target area. A treatment plan is determined based on the target area. The navigation method includes obtaining an ultrasound image of a scan plane including the target and obtaining a fiducial image of a fiducial pattern disposed on an ultrasound device. The obtained fiducial image is corrected and a correspondence between the fiducial image and a model image is found. A position of the surgical device is transformed to model coordinates. Then the ultrasound image and a virtual image of the surgical device is displayed to allow a surgeon to navigate the surgical device to the target using the displayed ultrasound image and the virtual image. The target is treated based on the treatment plan.
