The Children’s Hospital of Philadelphia is seeking healthy adolescents between the ages of 12-13, who are currently in the 7^th grade, to participate in the Sleep and Growth Study 2. 

The purpose of this study is to look at growth using a novel technique called diffusion tensor imaging (DTI) of the  growth plate in the knee. 

The purpose of this study is to examine breathing in healthy children ages 6-18 so that we may better understand the changes in function due to growth and the increase in size of the body organs.