radiography to sonography in america

i’m a student currently studying diagnostic radiography in the uk. once i graduate, i have plans on moving to america so i can move into sonography. i’ve searched everywhere for how or if im able to do this and no one seems to have any answers. am i able to do sonography in the us? what steps do i need to take? what course do i need to do? what are the fees? so many questions but any help at all would be much appreciated.