MAGNETIC RESONANCE IMAGING AND ITS APPLICATIONS

1. Magnetic Resonance
Imaging (MRI) in Food
Processing
Presented by:
Ruchika Zalpouri
&
Kulwinder Kaur

2. INTRODUCTION
MRI is a radiology technique
That uses magnetism, radio waves, and a computer to produce
images of body structures.
MRI is based on the principles of Nuclear Resonance Imaging
In1997, the first MRI exam was performed on a human being.
It took 5 hours to produce one image.

3. PRINCIPLE
MRI makes use of the magnetic properties of certain atomic nuclei.
Hydrogen nucleus (single proton) present in water molecules, and therefore in all
body tissues.
The hydrogen nuclei partially aligned by a strong magnetic field in the scanner.
The nuclei can be rotated using radio waves, and they subsequently oscillate in the
magnetic field while returning to equilibrium.
Simultaneously they emit a radio signal.
This is detected using antennas (coils)
Very detailed images can be made of soft tissues.

5. Kulwinder Kaur

6. MAIN COMPONENTS OF MRI
Scanner
Computer
Recording
hardware

7. SCANNER
An MRI scanner is a large tube that contains
powerful magnets.
Main components of scanner
• Static magnetic field coils
• Gradient coils
• RF (radiofrequency) coil

8. Gradient Coil
• Gradient coils are used to produce deliberate variations in the
main magnetic field
• There are usually three sets of gradient coils, one for each
direction.
• The set of gradient coils for the z axis are helmholtz pairs,
and for the x and y axis paired saddle coils.

9. Radiofrequency Coil
• RF coils act as transmitter and receiver
• RF coils are the "antenna" of the MRI system
• That transmit the RF signal and receives the return signal.
• They are simply a loop of wire either circular or rectangular
• Helmholtz pair coils consist of two circular coils parallel to
each other.
• They are used as the z gradient coils in MRI scanners
• Paired saddle coils are also used for the x and y gradient
coils.

11. Small samples of Top Red apples stored 6 months under
controlled atmosphere (expected to be non-mealy) and 2°C
(expected to be mealy) have been used for MRI imaging and
histograms were developed by using suitable image processing
software.
Application Of MRI In Food Texture

12. non-mealy
mealy

13. Ruchika Zalpouri

14. Application Of MRI To Monitor The
Process Of Ripening And Decay In Citrus
Fortune mandarins were coated with Biorend (IDEBIO S.L., Salamanca,
Spain) (a compound whose active molecule is chitosan), to investigate its
effect on maturity, decay, and damage, and therefore, to find a better
method for the long term storage of fruit.
A- Histograms of Mandarins coated with BIOREND of 0.1 group at 23oC during the first week
B- Histograms of Mandarins coated with BIOREND of 0.1 group at 23oC after 6 weeks
C- Histograms of Mandarins coated with BIOREND of 0.5 group at 23oC during the first week
D- Histograms of Mandarins coated with BIOREND of 0.5 group at 23oC after 6 weeks

15. -Can use whole 3D structure
for testing
- Non destructive method
- Study of dynamic changes
- Replicate analysis may be
performed.
- Blurry image due to product
movement
- Burning may occur due to
high radiofrequency energy.
- Non applicable for metal
bodies.
-Noisy and time consuming
procedure.
PROS CONS

17. Application of MRI to monitor the process of
ripening and decay in citrus treated with chitosan
solutions by Galed et al 2004
• Chitosan is a biopolymer, which has numerous applications in agriculture
and agroindustries. Coating fruit and vegetables with chitosan has some
positive advantages for the long-term storage of foods, because the film of
chitosan provides a kind of an active package, which allows a gradual
release of preservatives, thus inhibiting fungal growth and maintaining the
external appearance of the fruit for a longer time In this study, The effect of
chitosan as a fungistatic was also studied. To that end, the fruit was
maintained in a damp storage room, ideal conditions for the growth of
fungi. The magnetic resonance imaging (MRI) technique was used to
monitor the process of ripening and decay in the citrus fruit that had been
coated with chitosan. The dissolution of the chitosan on the mandarins and
oranges produced excellent results in terms of percentage of weight loss,
MRI, and visual appearance. © 2004 Elsevier Inc. All rights reserved.