Also, Doppler can detect abnormal blood flow within the heart, which can indicate a problem with one or more of the heart's four valves. Color Doppler. Color Doppler is an enhanced form of Doppler echocardiography. With color Doppler, different colors are used to designate the direction of blood flow.
Quick Answer. The age at which people grow armpit hair varies, but for boys it is often between the ages of nine and 14. Girls typically begin to grow this hair between eight and 13 years of age. Keep Learning.
Boys tend to show the first physical changes of puberty between the ages of 10 and 16. They tend to grow most quickly between ages 12 and 15. The growth spurt of boys is, on average, about 2 years later than that of girls. By age 16, most boys have stopped growing, but their muscles will continue to develop.