Figure 3. Comparison of image quality be-tween linear array high frequency probe(Figure3a) and small convex array high frequency probe(Figure 3b) in the same child ’ s colonic polyps:Small convex array high frequency probe is su-perior to linear array high frequency probe inpolyp display and blood perfusion (arrow). Fig-ure 4. Comparison of image quality betweenlinear array high frequency probe(Figure 4a) andsmall convex array high frequency probe(Figure4b) in the same child ’ s uterus: Small convexarray high frequency probe can clearly displayendometrial line in children(arrow).③a ③b④b ④a③a ③b④b ④a