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.
Stage four of male puberty commonly takes place when a boy is around 14 or 15 years old. Hair begins showing up in the armpits and on the face, and pubic hair begins to grow coarse. The boy's voice will even out and become deeper.