Presentation on theme: "MAGNETIC RESONANCE IMAGING 2003 Noble Prize Laureates in Physiology or Medicine Paul C. Lauterbur and Peter Mansfield."— Presentation transcript:
MAGNETIC RESONANCE IMAGING 2003 Noble Prize Laureates in Physiology or Medicine Paul C. Lauterbur and Peter Mansfield
Noble Prize 6 October 2003 Press Release The Nobel Assembly at Karolinska Institute has today decided to award The Nobel Prize in Physiology or Medicine for 2003 jointly to Paul C. Lauterbur and Peter Mansfield for their discoveries concerning “magnetic resonance imaging”
“for their discoveries concerning magnetic resonance imaging” Paul C. Lauterbur Peter Mansfield ½ of the prize USA ½ of the prize United Kindom University of Illinois University of Notingham Urbana, IL, USA. United Kingdom. b b. 1933
Paul C. Lauterbur born May 6, 1929 in Sidney, Ohio, USA. 1951 B.S. in Chemistry, Case Institute of Technology, Cleveland 1962 Ph.D. in Chemistry, University of Pittsburgh, Pennsylvania Professor of Chemistry, Radiology, New York University at Stony Brook Professor, University of Illinois, College of Medicine at Chicago 1985-Professor and Director, Biomedical Magnetic Resonance Laboratory, University of Illinois, College of Medicine at Urbana, IL.
Peter Mansfield born October 9, 1959 B.Sc. Queen Mary College, University of London 1962 Ph.D. Physics, University of London Research Associate, University of Illinois. 1964 Lecturer, University of Nottingham. 1968 Senior Lecturer, University of Nottingham. Senior Visitor, Max Planck Institut für Medizinische Forschung, Heidelberg Professor, University of Nottingham.
History of MRI Late 1800’s November 5, William Roentgen discovered X-rays. Roentgen discovered that: X-rays travel in straight lines, could not be refracted or reflected did not respond to magnetic or electric field. February, 1896, X-rays were being used clinically in the United States.
History of MRI In the 1930’s, a physics phenomenon was discovered, called nuclear magnetic resonance or NMR. Felix Bloch, working at Stanford University, and Edward Purcell, from Harvard University, discovered NMR. In NMR nuclei were placed in a magnetic field, they absorbed energy in the radiofrequency range of the electromagnetic spectrum, and re- emitted this energy when the nuclei transferred to their original state.
History of MRI This phenomenon was termed NMR as follows: "Nuclear" as only the nuclei of certain atoms reacted in that way; "Magnetic" as a magnetic field was required; "Resonance" because of the direct frequency dependence of the magnetic and radiofrequency fields.
History of MRI For their discovery of NMR Bloch and Purcell were awarded the Nobel Prize for Physics in Use of NMR to investigate the chemical composition and physical structure of matter. Relaxation times, T1 and T2. T1: Time taken by nuclei in test samples to return to their natural alignment T2: Duration of the magnetic signal from the sample.
History of MRI In 1970s Raymond Damadian, proposed that each tissue in the body has a different relaxation time, but cancerous tissue has an abnormally long relaxation time. He believed that the NMR could be used as an “external probe for the internal detection of cancer” Damadian presented first commercial NMR scanner at the annual meeting of the American Roentgen Ray Society in 1980.
History of MRI Paul C. Lauterbur determined the origin of the radio waves by analysis of their characteristics. Discovered the possibility to create a two- dimensional picture by introducing gradients in the magnetic field. In 1972, obtained the first MRI.
History of MRI Pater Mansfield further developed the utilization of gradients in the magnetic field. Signals could be mathematically analyzed. Showed how extremely fast imaging could be achievable. In 1976, he and his colleagues created the first MRI of a human body part, a finger.
What is an MRI? Magnetic Resonance Imaging (MRI) :safe and noninvasive test. Diagnostic technique :uses strong magnetic field and pulses of radio waves. Produces pictures of structures inside the body. Images :slices of an organ or part of body. MRI’s computer: 3-D images.
How it works? Body :strong magnetic field. Machine uses :strong magnetic field and pulses of radio waves. Machine creates an image :how hydrogen atoms react. Usually images are created as single slices of organs or structures. MRI computer combine them to give a 3 D image.
Using Our Body’s Magnets Because of predictions from physics and math we know there are very weak magnets in all living tissues These magnets are atoms with unpaired numbers of protons and electrons like hydrogen 1 H There are billions and billions of hydrogens in your body
Using Our Body’s Magnets 1 H do not have a matched pair of neutrons and protons When atomic nuclei do have perfectly matched neutrons and protons, these always arrange in pairs and rotate in opposite directions to one another With 1 H, there is no match and there is a nuclear spin and slight + charge
Using Our Body’s Magnets One way is to stick these very weakly magnetic tissues in a gigantic, strong MAGNET and see what happens!!!!!! This is the principle of Magnetic Resonance Imaging, (MRI) used in research and diagnostic radiology today!!!!!!!!!
A moving electric charge produces a magnetic field Protons have a positive charge Protons spin Protons produce a small magnetic field
No external field… Randomly aligned
External field… Aligned with field
Some protons align with the field… Some protons align against the field… Protons continually oscillate – always a slight excess aligning with field Aligning with field – slightly lower energy state
Protons Wobble Spinning protons wobble about the axis of the external field Frequency of precession = Resonance Frequency Depends on strength of magnetic field
RF Pulse Apply RF pulse at resonance frequency Protons absorb energy Protons ‘jump’ to a higher state
What goes up… …must come down Energy is re-transmitted as RF signal
Advantages of MRI Diagnosing multiple sclerosis (MS) Diagnosing tumors of the pituitary gland and brain. Diagnosing infections in the brain, spine or joints Visualizing torn ligaments in the wrist, knee and ankle
Advantages of MRI Visualizing shoulder injuries Diagnosing tendonitis Evaluating masses in the soft tissues of the body Evaluating bone tumors, cysts and bulging or herniated discs in the spine Diagnosing strokes in their earliest stages.
Disadvantages of MRI Not for everybody. machine makes a tremendous amount of noise. require patients to hold very still for extended periods of time. Orthopedic hardware (screws, plates, artificial joints) in the area of a scan can cause severe artifacts (distortions) on the images. very expensive.
Future of MRI Very small scanners. Functional brain mapping. Ventilation dynamics of the lungs through the use of hyperpolarized helium-3 gas. Image strokes in their earliest stages. Limitless future
Laser Polarized Xenon MRI Functional Brain Imaging Map of Blood Flow in the Rat Brain
Functional Brain Imaging Blood Oxygenation Affects Contrast Metabolism uses oxygen Contrast Reveals regions of oxygen consumption University of Minnesota
Laser Polarized Gas Images University of Virginia
Sources used: s/2003/ Slides provided by Dr. Vankley.