Sheih Chung-pin points out that ultrasound is a form of "non-ionizing radiation." It can even be used on expectant mothers and their fetuses, so there are no safety concerns about its use on young children.
謝從賓指出，超音波是一種「非游離輻射線」，連孕婦、胎兒都能做，小朋友使用更沒有安全上的顧慮。