Ultrasound images of uterine leiomyosarcoma (a) and leiomyoma (b). Left: US B-mode image Right: VTI. The results of gray-scale and VTI are shown in Figure 1. Irregular distribution of blue, yellow, green and red was seen in VTI suggesting a heterogeneous inner structure. Notable blue was present in high echoic spots shown on gray-scale imaging. In VTQ study of the leiomyosarcoma, four ROIs were placed.