My 15yo DC is desperate to be much taller. He was 91st centile at birth, but his DNA comes from some very tall, very short, and inbetween people, so we have been managing his expectations. Many of his friends have shot up past him over the last year or so, whereas he has stayed stubbornly at 5' 10". Recently, a medic at a STEM Careers event used an ultrasound scanner to take an image of his hand. She said she could tell from his growth plates that he was going to grow massively. He's very, very pleased! But is it likely to be accurate?