Due Tonight!
Assignment 5
PyDicom
load CT volume, slice it, adjust window/level
coming soon!
The AMIGO Suite
Jayender Jagadeesan, PhD
Harvard Medical School
Mahsa Geshvadi
Magnetic resonance imaging
MRI
Magnet
Extremely Powerful
Always On!
1.5 Tesla
3 Tesla
7 Tesla
60,000x stronger than earth magnetic field
$6.5 million
Coils
to enhance contrast
Image Volumes
Voxel size for CT: 0.625-1.25 mm^3
similar to MRI
0.1-1 mm^3
Dr. Raymond Damadian's Indomitable (1977)
Sir Peter Mansfield (1973)
+ Paul Lauterbur
Magnet
Radio Frequency
Gradient Coil
Electro-Magnetic Field
cuts large Magnetic Field into
smaller sections
stimulates atoms
Hydrogen Atoms (Water + Fat)
specific frequency of resonance is called the Larmour frequency
Different tissues (such as fat and water) have different relaxation times
Magnet
RF Pulse
Echo Time (TE)
Repetition Time (TR)
different per tissue!
Fourier Transformation
snapping back
Structural MRI
Structural MRI
MRI Physicist develops sequences
Diffusion Weighted Imaging (DWI)
Motion of water molecules
White Matter Pathways
Approximation!
DTI
fMRI
functional MRI
localized brain activity
Magnetic resonance angiography (MRA)
Aneurysm
Stenosis
brain tumor
- Tumors
- Inflammation
- Certain organs’ blood supply
- Blood vessels
Gadolinium
Contrast Agent
MRI $2000
CT $1200
10 mins
1 hour
better contrast
super noisy
- An IUD
- Artificial joints
- A pacemaker
- Eye implants
- Aneurysm clips
- Shrapnel
- Orthopedic hardware
- Dark tattoos
MRI: Risk
The AMIGO Suite
Is an MRI in there?
Jayender Jagadeesan, PhD
Harvard Medical School
Mahsa Geshvadi
