Figure by Martijn Frijlink What is ultrasound? medical ultrasound 440 Hz audible range 40 MHz 1 MHz 20 kHz end of piano 4.2 kHz start of piano 27.5 Hz Ultralyd er også lyd …piano with “ultrasound keys” Figure by Martijn Frijlink
v is sound speed in air (~340 m/s) Echoes 1001, 1002,…. Hoi ! Hoi ! Hoi ! Hoi ! Et fenomen vi har med lyd er ekko. På fjellet… eller for den slags skyld I Glassgården på Gløshaugen.. Echo = reflected sound wave s = v * t v is sound speed in air (~340 m/s) Figure by Hans Torp Department of circulation and medical imaging
How are ultrasound images made? Ultrasound images represent the echoes we get back when short high frequency pulses are sent into the body. Figure by Martijn Frijlink Department of circulation and medical imaging
….. Demonstrer M-mode i akvarium! Demonstrer B-mode i akvarium! M-mode: depth against time. Instead: point the beams in several direction within a plane of the heart Animation by Jonas Crosby Demonstrer M-mode i akvarium! GE Vivid 7 scanner Demonstrer B-mode i akvarium! Figure by Svein A. Aase Figure by Jonas Crosby
Figure by Jonas Crosby
Hindring i avstand fra probe gir skygge i ultralydbildet Skygge fra lunge
Hindring nær probe gir dårlig bildeskarphet Skygge fra ribbein