MRI+-+IVAN

Back to HOME > IB PHYSICS > WAVES > FORCED OSCILLATION > IB HL 2012 EXAMPLES EXAMPLE OF RESONANCE BY Ivan Kwok MRI uses Destructive waves to create the image.

Define destructive wave. Two equal wave pulses on opposite sides subtract when they meet., where one pulse exactly cancels with the opposite pulse. For a moment there is no pulse at all. Which can also understand as destructive interference. [1]

RESONANCE – It is the frequency that is close to the **natural frequency** of the system with large amplitude, there is an exchange of energy at a particular frequency between two systems. In this case, it’d be ranges from 2.13 MHz to 85 MHz. [2]

It uses radio frequency. It **damps** over time, usually after 20 waves. So in other words, it loss energy when it go through the human body which is the medium, it may lose energy. For MRI to work, it is is **forced to oscillate** at a differen frequency than its natural one in order to show the difference in the MRI image with a different driving frequency to start off with.

[1] http://search.yahoo.com/r/_ylt=A0oGdbiGa1BPvjwAvOVXNyoA;_ylu=X3oDMTE0YmZtamMzBHNlYwNzcgRwb3MDMQRjb2xvA3NrMQR2dGlkA1JDRjAyOF84Mg--/SIG=121779acf/EXP=1330699270/**http%3a//cpo.com/ipcres/pdfs/unit4/Ch12Sec3.pdf [2] www.simplyphysics.com/page2_4.html