Medical Imaging

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Medical Imaging

• Jessica Ramella-Roman Ph.D.

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Instructor

• Office ---gt Pangborn Hall -105B
• Email ---gt ramella_at_cua.edu
• Office phone ----gt 202 319 6247
• Office hours ? By appointment
• Research ---gt Biomedical Optics
• Lab ---gt Pangborn Hall, 118

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Textbook

• The essential physics of medical imaging, second
  edition, J.T. Bushberg, J.A. Seibert,
  E.M.Leidholdt, JR. J.M. Boone, Editor Lippincott
  WilliamsWilkins
• ISBN 0-683-30118-7
• CLASS SLIDES WILL BE DISTRIBUTED

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More suggested reading

• Naked to the Bone Medical Imaging in the
  Twentieth Century (Paperback)by Bettyann Kevles
• Emc2 A Biography of the Worlds Most Famous
  Equation by David Bodanis

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Grading

• 30 Homework and class participation
• 30 Midterm Exam
• 40 Final Exam

http//policies.cua.edu/academicgrad/gradesfull.cf
miii
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CUA Grading System

• http//policies.cua.edu/academicgrad/gradesfull.cf
  miii

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Class Structure

• 1 h 15 min - lecture
• 20 min break
• 1 h 15min lecture and discussion
• I will ask you to read the chapter we are dealing
  with before hand.

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Class calendar
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Class calendar
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Class calendar
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Class calendar
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WHAT IS MEDICAL IMAGING?
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Medical imaging

• Includes many imaging modalities
• X-ray, Ultrasound, CT, PET, MRI, and many others
• Uses physics, math, engineering tools, biology,
  (...) to image different part of the interior of
  the human body.

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Radiation is

• Energy that travels through space and matter
• We are interested in electromagnetic radiation
• Xray
• Visible Waves
• Gamma rays ()

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Electromagnetic spectrum
wavelength (nm)
1015 1012 109 106 103 100 10-3 10-6
frequency (Hz)
60 16 1012 1018 1024
UV
Radio, TV, Radar, MRI
IR
g-Rays
X-Rays
Radiant Heat
Cosmic Rays
10-12 10-9 10-6 10-3 100 103 106 109
energy (eV)
visible
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Magnetic resonance Imaging (MRI)

• Paul Lauterbur and Peter Mansfield 1970-1980
• Uses very powerful magnets (1.5 Tesla) and the
  nuclear magnetic
• resonance properties of the proton
• Detects the radio frequency emitted by the
  protons
• (Proton spin flip)
• Tomographic imaging modality
• 10 minutes for a complete scan

images from http//nobelprize.org/medicine/laur
eates/2003/press.html
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X-Ray imaging

• Discovered by Wilhelm Roentgen Nov 8, 1895
• Published December 12, 1895
• Uses X-Rays (0.01-0.1 nm)
• Ionizing radiation
• 10-100 KeV
• Resolution mm
• Penetration all body
• Mammography is done with
• low power X-rays

images from http//imagers.gsfc.nasa.gov/ems/xr
ays.html
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Computer Tomography (CT)

• Full body CT inventor 1970-2 Robert Lendley
• Uses X-Rays, rotates the source detector around
  the body
• Very quick (10 sec)
• Image soft tissue and vascular network

images from http//www.radiologyinfo.org
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Ultrasound

• Inventor Donald 1957, used on pregnant woman in
  1958
• Uses sound waves
• Sound enters the tissues and is reflected by
  internal structures
• Echoes
• Its a scanning process
• Much less harmful than ionizing mechanism
• Doppler ultrasound is used to measure flow

images from http///www.medical.philips.com
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Nuclear Imaging

• Inventor Many over the years John Ernest
  Lawrence, Ager ...
• Uses the decay (X-Ray or Gamma-Ray) of a isotope
  that was injected in a patient to image internal
  organs (emission images)
• Gives information on the physiology of the
  patient
• PET-gt Positron Emission Tomography
• Radioactive isotopes Fluorine18 and Oxygen 15
  emits positrons (e)
• e combined to e- produces annihilation radiation
• Annihilation radiation similar to gamma-ray but
  produces 2 photons ( in opposite directions)
• Uses a ring of detector to record the photon
• Produces a tomographic image
• SPECT-gt Single Photon Emission Computed
  Tomography
• Gamma ray or Xray emission from the patient is
  recorder at several
• different angle. (tomography)
• Radioactive isotopes Fluorine18 and Oxygen 15
  emits positrons (e)

images from http///www.medical.philips.com
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• PLEASE READ CHAPTER 1 and 2 of the text book by
  next week,