The punctate blood flow signal is the blood flow signal within the blood vessels detected with color Doppler when doing an ultrasound exam. For example, if a solid nodule is found within the gland during a thyroid exam, it is important to measure the size, describe the shape, and observe whether the edges of the nodule are smooth, and finally, with color Doppler, detect whether there is a blood vessel supply within and around the nodule. If only a punctate blood flow signal is seen, which is relatively small, indicating that only a small amount of blood vessels are growing in or around the nodule, consider this nodule to be growing relatively slowly, as long as it is reviewed regularly. If abundant blood flow signals are detected in or around the nodule, not in the form of dots but in the form of tubes, it means that it has abundant blood flow supply and will grow faster, and should be closely observed and treated surgically if necessary.