1. A method of needle visualization enhancement in ultrasound imaging, comprising: performing a Radon transform (RT) on a sequence of frames to detect line features in the frames, a frame comprising ultrasound (US) radio-frequency (RF) data obtained during monitoring the insertion of a needle into a subject or an US image reconstructed from the RF data; removing line features which remain substantially stationary among the frames as false needles while locating a line feature which extends among the frames as the needle; and overlaying the location of the line feature as the needle on an US image of a frame to produce an enhanced image to be displayed.