1. Magnetic Resonance Imaging
MRI

2. Objectives: Advantages of MRI over other Modalities
Discuss the MRI historical development, and to know the significant person who discovered MRI.
MRI discovery time line
Persons involved
What are their Contributions
Overview of the basic principle of MRI
Advantages of MRI over other Modalities
Different Components of MRI

3. Historical Influence to MRI
MRI Topic 1

5. Democritus
In early 400B.C
First to theorize that all matter consist of both invisible and indivisible particles
Greeks
Also noted and observed that a piece of amber, when rubbed by fur, would attract specific particles or object.

6. AMBER

7. MAGNESIA TURKEY City of Magnesia is the origin of the term magnetism.
Observed that when certain rock formation were spun on their axes, they always and immediately returned to their original orientation. These magnetize structure, which are called lodestone.

8. LODESTONE

9. BAPTISTE-JOSEPH FOURIER
Introduced a complex mathematics that translate raw MR signals into spatial location while serving emperor napoleon of France

10. Our ancestors theorize that there was relationship between electricity and magnetism.
However, its relationship remained unsolve until approximately 2000 years later.

11. Hans Christian Oersted
1819 discovered that electricity produces magnetism when he noted that a compass needle would deflect in the presence of an electric charge.

13. Michael Faraday
Stated and successfully demonstrated that electricity can produce magnetism.
In 12 years later, michael faraday stated
For his contribution, and many others michael faraday is regarded by many as the father of electricity.

14. Michael Faraday
Calculated the velocity and propagation of electromagnetic waves and predicted the existence of other waves in addition to the ultraviolet and infrared regions.
In 12 years later, michael faraday stated
For his contribution, and many others michael faraday is regarded by many as the father of electricity.

15. Sir James Clerk Maxwell
In 1860 discovered magnetic lines of force could be mathematically expressed.

16. Heinrich Hertz of Germany
In 1868 discovered that invisible electromagnetic wave do exist and that all electromagnetic waves are identifiable by their characteristic wave frequency values.

17. Heinrich Hertz of Germany
Electromagnetic spectrum – the categorical arrangement of the wave energies corresponding to their properties, began to take form.

19. Wilhelm Conrad Roentgen Marie Curie
Nov. 8, 1895 discovered the x-ray
Marie Curie
In 1896 discovered the gamma rays by experimenting on radioactive phosphors.
Their discoveries soon demonstrated that high frequency wave energies were identifiable, detectable, measurable and often biologically damaging.

20. Post WORLD WAR II
Some of the technology advances associated with the world war 2 laid the groundwork for utilizing sonograpghy (submarine detection) and nuclear medicine (atomic energy) for human.

21. Felix Bloch & Edward Purcell
1946
Explore the mystery of atom.
They noted that when a test tube sample of a pure substance was magnetically energized and RF bombarded the excited atoms themselves would respond by singing their own atomic ‘’tune’’.

22. Felix Bloch & Edward Purcell

23. Felix bloch & edward purcell
These tune signal were detected and recorded into spectroscopic images, corresponding to their frequency values.
Virtually overnight Nuclear Magnetic Resonance (NMR). The prelude to MRI, was about to be born.

24. Felix bloch & edward purcell
Bloch and Purcell were recipients of the Novel Price in 1952 for their major contribution in uniquely discovering and implementing the use of atomic energy for analytical purposes.

25. END…

26. Magnetic Resonance Imaging
(BASIC PRINCIPLES) MRI TOPIC 2

27. MRI Originally called Nuclear Magnetic Resonance or NMR.
“Nuclear” indicated that the radioactive atomic nucleus played an important role.

29. Basic Principle of MR
A certain atomic nuclei, if placed in a magnetic field, can be stimulated by (absorb energy from) radio waves of the correct frequency.
Following this stimulation, the nuclei release the extra absorbed energy by transmitting radiowaves (the MR) signal, which can be received by an antenna and analyzed.

30. Behavior of a hydrogen nuclei

31. Advantages of MRI over other Modalities
Contrast Resolution
Multi-Planar Imaging
No Radiation

32. CONTRAST RESOLUTION Principal advantage of MRI
Allows visualization of low- density objects with similar soft tissue characteristics, such as liver- spleen or white matter – gray matter
It is a function of several intrinsic properties of the tissue being imaged.

33. MRI HAS HIGH CONTRAST RESOLUTION

34. Multi-Planar Imaging
Ability to obtain direct transverse, sagittal, coronal and oblique plane images

35. CORONAL VIEW

36. SAGITTAL VIEW
TRANSVERSE VIEW

37. TRUE OR FALSE?
TRUE OR FALSE?????

38. NO Radiation MRI does not use Ionizing radiation
MRI uses RF electromagnetic radiation and magnetic fields, which do not cause ionization and therefore do not have associated potentially harmful effects of ionizing radiation

39. MRI Hardware
3 main components:
Gantry
Computer
Operating Console

40. Gantry
Is the large, usually cylindrical device that accommodates the patient during imaging
MRI gantry does not have moving parts- everything is electronically controlled
The patient aperture is usually cm in diameter

41. WHERE IS THE GANTRY??

42. RF COILS
RF coils which is called the RF probe, surrounds the patient in this aperture
Gradient coils, shim coils, and in the case of an electromagnetic, primary coils all surrounds the RF probe to produce the static magnetic field

43. RF COILS
BODY COIL
HEAD COIL

44. Computer Similar to CT, only faster and bigger
During MRI examination, more data are collected and the computations required are longer and more difficult than the CT

46. Operating Console MRI patient does not move
MRI console has RF controls rather than kVp, mA and scan time controls

47. MRI OPERATING CONSOLE

48. MRI Overview
The hydrogen nuclei in the Patient- protons- behave like tiny magnets
Hydrogen makes up 80 % of all atoms found in the human body, making hydrogen extremely useful for MRI.
Because Hydrogen is a single- charge spinning nucleons, the hydrogen nucleus exhibit relatively strong magnetism

49. END..