1. Magnetic resonance imaging (MRI) is a medical imaging technique that uses magnetism, radio waves, and a computer to produce detailed images of organs and tissues in the body. 2. MRI scanners use powerful magnets and radio waves to align hydrogen atoms in the body and produce signals that can be used to generate cross-sectional images of organs and tissues. 3. The first human MRI was performed in 1977 and took 5 hours to produce an image, whereas modern MRI machines can generate high-quality images much more quickly.

1. - Dr Nisar Ahmed Arain
Assistant Professor
Anesthesia/Critical Care/ER
-M.R.I
MAGNETIC RESONING IMAGING

2. MRI is a radiological technique
Its Uses
a-Magnetism
b-Radio waves and a
c-Computer
d-to produce images of body structures
e--MRI is based on the principals of
NMR(Nuclear Medical Resonance)
The First Human examination of MRI
was performed in 1997 and
it took 5 hours to produce an image
- MRI

3. -MRI MACHIINE

4. -Magnetic Resonance Imaging Inventor
-FATHER OF MRI

5. 1-Most ailments of the Brain, including Tumors
and sport Injuries
2-Musculo skeletal problems
3-Most spinal conditions, injuries, Vascular
abnormalities
4-Female Pelvic problems
5-Prostate problems
6-Abnormal Gastro Intestinal tract conditions
7-Ear, Nose, and Throat conditions
8-Soft tissue and Bone Pathological conditions
-WHAT CAN BE DIAGNOSED
BY AN MRI SCAN

6. 1-A Cardiac Pacemaker
2-Certain Dips in your head from Brain
operations
3-A Cochlear implant
4-A metallic foreign body in your Eye
where you had surgery in last 8 weeks
5-If you are Pregnant
-WHO CAN HAVE AN
MRI SCAN

7. 1-MRI makes use of the magnetic
properties of certain atomic
nuclei
2-Hydrogen nucleus (single proton)
present in the water molecules and
therefore all body tissues
3-The hydrogen Nuclei partially
aligned by a strong magnetic field
in the scanner.
-PRINCIPLES OF MRI

8. -PRINCIPLES OF MRI cont.
4-The nuclei can be rotated using
radio waves, and they subsequently
oscillate in the magnetic field while
returning to equilibrium
5-Simultaneously they emit a radio
signal, and this is detected using
antenna (coils)
6-Very detailed images can be made of
soft tissues

9. Randomly arranged
Hydrogen Atoms
-PRINCIPLES OF MRI cont.
After the application of strong
magnetic field

10. -PRINCIPLES OF MRI cont.

11. 1-Scanner
2-Computer
3-Recording Hardware
-MAIN COMPONENTS OF MRI

12. 1- An MRI Scanner is a large tube
that contains powerful magnets
2-Main components of scanner are
a-Static Magnetic field coils
b-Gradient coils
c-RF (radio frequency) coils
-SCANNER

13. -MRI SCANNER CUTAWAY

14. 1-Three methods to generate magnetic field
a-Fixed Magnet
b-Resistive Magnet
c-Super conducting Magnet
2-Fixed Magnets and Resistive Magnets are generally
restricted to field strengths below 0.4t
3-High resolution imaging systems use super conducting
Magnets
4-They need coils to be soaked in liquid Helium to reduce
their temperature to a value close to absolute zero
-STATIC MAGNETIC FIELD COILS

15. 1-Gradient coils are used to produce deliberate
variations in the main Magnetic field
2-There are usually three sets of gradient coils,
one for each direction
3-The variation in the Magnetic field permits
localization of image slices as well as
phase encoding and frequency encoding
4-The set of gradient coils for the Z axis are
Helmholtz pairs, and for the X and Y
axis are paired saddle coils
-GRADIENT COILS

16. -MRI Scanner Gradient Magnets

17. 1-RF coils act as transmitter and receiver
2-RF coils are the “ANTENNA” of the MRI
system
3-That transmit the RF signal and receives
the return signal
4-They are simply a loop of wires either
circular or rectangular
5-Helmholtz pair coils consist of two circular
coils parallel to each other. They are used
as the Z gradient coils in MRI Scanners
6-Paired saddle coils are also used for the X
and Y gradient coils
-RADIO FREQUENCY COIL

18. 1-No ionizing Radiation
2-Variable thickness in any plane
3-Better contrast resolution
4-Many details are achieved without I/V
contrast
-ADVANTAGES OF MRI

19. 1-Very Expensive
2-Dangerous for patients with
metallic devices placed within
the body
3-Difficult to be performed on
daustrophobic patients
4-Movement during scanning may
cause blurry images
5-RF transmitters can cause severe
burns if mis handled
-DISADVANTAGES OF MRI

20. SHAPES OF MRI
MACHINE

21. -a-CLOSED MRI MACHINE

22. -b-OPEN MRI MACHINE

23. -UPRIGHT MRI

24. 1-Since the earlier 1990’s FMRI had come
2-FMRI is based on the same technology as
MRI
3-FMRI looks at blood flow
4-It is a technique for measuring Brain activity
5-It works by detecting the charges in the
blood oxygenation and flow that occur in
response to neural activity
-FUNCTIONAL MRI

25. 1-MRI
2-Views anatomical
structure
3-Focuses on protons in
Hydrogen Nuclei
4-High Spatial resolution
5-Utilized for
Experimental purposes
-DIFFERENCE BETWEEN
MRI and FMRI
1-FMRI
2-Views Metallic
function
3-Calculates Oxygen
levels
4-Long distance
Resolution
5-Utilized for
Diagnostic purpose

26. -MRI Scan
-DIFFERENCE BETWEEN MRI and FMRI
-FMRI Scan

27. -Comparison between
X Ray system=CT System=and MRI System