白袍恐懼症

Reanl echo

Renal: 9~12 cm

中央白色的collecting system，可見多個兩片亮白色片狀一組的管壁，若兩片亮白色片狀的距離增大，表示 duct dilatation

posterior enhancement  ex: cyst

sound passes through an anechoic structure, no echoes are reflected and so they are all available to pass through, more echoes are seen deep to the anechoic structure because more sound is available

acoustic shadowing  ex: stone

sound wave encounters a very echo dense structure, nearly all of the sound is reflected, resulting in an acoustic shadow

若看到又小又白又亮的點，可能是血管鈣化所造成(不一定是stone)