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.
Reviewed by Brunilda Nazario, MD. Oct. 20, 2012 -- American boys are starting puberty up to two years earlier than decades ago, new data show. Boys are entering puberty at an average age of 10 among whites and Hispanics, and at an average age of 9 among African-Americans.About a third of boys start to mature sexually up to two years earlier than average.hose who start puberty soonest aren't always the first to finish. In the Herman-Giddens study, the average age of full sexual maturity for boys of all races and ethnicities was about the same -- late in the 15th year. About a third of these boys reached full maturity two years sooner.