Post on 30-May-2020
Kelly BeamMark Bailly
Danielle AllenAthena Turner
Magnetic Resonance Imaging
Greg Pawlowski Ryan YanigaJoseph Sisson
MRI History
• First Images were taken in the 1970s• NMRI or MRI?
How does MRI work?
• Spinning Protons Act Like Little Magnets
• They Align With AnExternal Magnetic Field (Bø)
How does MRI work?
*Based on ρ=111 for 12mM aqueous NiCl2
50 - 10053 - 940.2 - 0.75Adipose
45 - 9020 - 670.95 - 1.82Muscle
5 - 4450 - 1650.5 - 2.2Meninges
85 - 12561 - 1091.09 - 2.15Gray
70-9061-1000.76 - 1.08White
70-230110 - 20000.8 - 20CSF
ρ*T2 (ms)T1 (s)Tissue
Questions ?
The End
History• 1946
– Felix Bloch and Edward Purcell• 1973
– Paul Lauterbur• 1975
– Richard Ernst• 1977
– Peter Mansfield and Andrew Maudsley• 1977
– Raymond Damadian• 1980
– FONAR Corporation
How it Works• Magnetic Resonance Imaging (MRI)
• Intense Magnetic Field• Second Electromagnetic Field
• Oscillated, Specific Radio Frequencies• Perpendicular Alignment of Atoms
• After Second Field is Turned Off • Atoms in the Body
The Larmor Equation• ω=γB
–Ω = Frequency of Angular Momentum • Larmor Frequency
–γ = Represents the Gyromagnetic Ratio –B = Magnetic Field
Nucleus Gyromagnetic Ratio (MHz / T)1H 42.6
19F 40.123Na 11.313C 10.72H 6.517O 5.8
The Larmor Equation
Relation to Class• Magnetic fields
–Static–Time-varying –Maxwell’s equations
• Gradients– In relation to magnetic fields
References • Magnetic Resonance Imaging
–Stwart C. Bushong• MRI for Technologist
– Peggy Woodward / Roger Freimarck• http://en.wikipedia.org/wiki/Magnetic_reson
ance_imaging• http://www.physics247.com/physics-
tutorial/electromagnetism-mri.shtml