Solution..

Assignment 5

PyDicom

load CT volume, slice it, adjust window/level

Due Wednesday 4/14 !

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

Magnet

Radio Frequency

Gradient Coil

Electro-Magnetic Field

cuts large Magnetic Field into

smaller sections

stimulates atoms

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)

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

Tina Kapur, PhD

Executive Director of Image Guided Therapy

Is an MRI in there?

CS480 Lecture 28

By Daniel Haehn

CS480 Lecture 28

Slides for CS80 Biomedical Signal and Image Processing at UMass Boston. See https://cs480.org!

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