Figure 1c. Uterine AVM in a 22-year-old woman who had undergone curettage on several occasions for spontaneous abortion. Evaluation of hysterectomy material had confirmed the presence of a malformation. (a) Transabdominal gray-scale US image shows multiple anechoic spaces. (b, c) Color Doppler US images show a mosaic pattern of color signals within the cystic spaces. (b) Spectral analysis of the arterial vessels within the lesion shows high blood flow velocity with a low resistive index. (c) Spectral analysis of venous flow shows high blood flow velocities and peak systolic velocities, findings similar to those seen in b.