MRI is a type of diagnostic test that can create detailed images of nearly every structure and organ inside the body. MRI uses magnets and radio waves to produce images on a computer. MRI does not use ionizing radiation. Images produced by an MRI scan can show organs, bones, muscles and blood vessels.

1. MRI
The human body consists of about
85% water, which consists of 2
hydrogen and 1oxygen atom.
" MR imaging is based on proton
imaging. Protons are +ve charged
particles in the nucleus of every atom
and have rotatory movement called
spin.
Any charge, which moves generates
current and every currenthave a
small magnetic field around it. So
every spinninghydrogen proton have
asmallmagntic field around it.
InMRI, this smallmagnetic field of
hydrogen protons areused to
produce diagnostic image.

2. Ro
Midsagittal
Scanning projections
R.L
Parasagita
"Sagittal view : viewing body from
right toleft direction.

3. T
Top
Bottom
"Transverse view :
viewing body from
upper and lower
direction.

4. C
Back Front
"Coronal view :viewing
body from anterior and
posterior direction.

5. Equipment used in MRI
1. Gantry:it is adoughnut
shaped device containing the
magnet.
"Magnet :toproduce magnetic
field.
"Bore :the empty space inthe
middle ofthe magnet is called
bore and this is where the
patient interact with magnetic
field and reveal diagnostic
information.

6. 2. Patient table:
"The patient table supports the
patient and allows the patient to be
moved into the bore for scanning.
" The table is curved for patient
comfort and also conforms to the
shape of the bore(60 cm).
" It is constructed of non-magnetic
material toavoid altering the
magnetic field (plastic, copper,
aluminium, rubber).
"The table allows the patient to be
raisedand lowered to assist the
patient in lying on the table.

7. 3.Computer
" The computer is a major
component in the
formation of MR image.
" It process different signals
from the patient body to
create MRimage.
4. Display
"The datacan be viewed
into routine transverse,
sagittal and coronal.

8. Procedure
Although ionizing radiation is not used in MRI but stillthere
are important salety consideration sleps ivolved.
1
2.
3.
4.
MRIincludes strong rmagnetic filed theretore paticnt
with implants,prostheses (artificial body limb).
aneurysm clips, pacemakei, heart valves, breast
implant,cochlear implant (hearingaid)should be
checked properly betore placing palient MRIroom.
Non-metallicimplant materials an leadtosignificant
heatingunder magneticfield which can leado
misdiagnosis
Presence of tattoo, mascara,piering should alsobe
avoided.
Ferro magnelic material broughtintothe imaging
room 1or eg. IV pole are attraded by magnetic field
and can bEComedeadly projectile for thepaticnt with
in the boreof the magnet.
After confirmation the patient is asked to lie down on the
examinatian table until the scan is completed.

9. Indication andcontraindications
Indications
Torn ligament
"Soft tissue problems
"Spinal problems
" Nerve issues
" Inflammation
Contraindications
"Any non-removable metallic
device.
" Claustrophobia
"Pregnancy (if not emergency
case)

10. "Themost common bio-effect of MRsystem is tissue heating caused by
magnetic field energy deposition.
Metallic taste
" Flushing of face
"Blur vision
MRI Biological Effects
"ECG :change in naturalwave form for ashort duration.
Disadvantage
"MRIScans produce loud noises which saome people mayfindstressful.
"Longer scan time.