1. A process for needle visualization comprising: inserting a needle configured to be inserted into a tissue; obtaining an ultrasound image including the needle, where the ultrasound image is a grayscale image; receiving, with a processor, a plurality of signals from a needle tracking system; determining, with the processor, an estimated position of the needle in the ultrasound image based on the the plurality of signals from the needle tracking system, defining, with the processor, a region comprising a plurality of pixels, where the region is larger than the needle; assigning, with the processor, a probability to each of the pixels within the region of the ultrasound image as being representative of the needle; creating, with the processor, a colorized image of the needle in the ultrasound image with the processing unit by applying a first color to a first subset of the pixels within the region with a higher probability of being representative of the needle and applying a second color to a second subset of the pixels within the region with a lower probability of being representative of the needle; and displaying the ultrasound image with the colorized image of the needle on a display.