Color Doppler ultrasound, within the endometrium or at the base of the endometrium, may show one to several strips, tubular mesh, or punctate colored blood flow signals. When there is basal invasion, the localized blood flow signal of the affected base increases and the blood supply is rich. Based on this ultrasound performance, it can be used to assist in determining the degree of basal invasion. On spectral Doppler, an abnormal low resistance type can be detected within the endometrium, at the endometrial base, and at the affected basement. The arterial blood flow spectrum, rich in diastole, has a resistance index of <0.4, mostly as low as 0.35 or less. The peak systolic flow velocity of blood flow is often higher than 20 cm/s and even reaches more than 40 cm/s.