ultrasound imaging
Post on 01-Jan-2016
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Ultrasound Imaging• Basic Principle: sound wave pulse emitted at >20 kHZ,
some reflected, and some transmitted. • Reflection from single signal – A-scan
Reproduced from http://folk.ntnu.no/stoylen/
B-Mode Imaging
• Energy displayed as: - amplitude, as in A-mode, - brightness, as in B-mode, - motion curve, as in M-mode.
• 2D image formed with linear or angular sweep.
Reproduced from http://folk.ntnu.no/stoylen/
B-Mode 2D Imaging
• Image built line by line: i) emitting the pulse, ii) waiting for reflected echoes iii) tilt beam & emit next pulse.
• Cardiac application: 2D visualization of beating heart.
Reproduced from http://folk.ntnu.no/stoylen/
Doppler Imaging
• Idea: moving source of sound undergoes Doppler shift. 1. Moving train2. Blood flow: exploit frequency shift to estimate motion.
Reproduced from http://folk.ntnu.no/stoylen/ & Wikimedia Commons.
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