2. is
are essential in the development of
many scanning technologies like:
X-rays, CT scans, MRI scans
And new scanning technologies
PET scans and MEG
3. Learning objectives
At the end of the activities you can:
1. Explain the work of the tolls
2. Distinguish the advantages and
disadvantages of x-rays, CT scans, MRI
scans, PET scans and MEG scans
3. shows the results of a every scanners
X-rays, CT scans, MRI scans
And new scanning technologies
PET scans and MEG
6. X-rays
X-rays is very little
ordinary light can pass
through skin. It’s either
absorbed at the surface
or reflected back.
X-rays to “see” inside we
need a kind of “light”
with more energy.
Ordinary Light
X rays
Skin
8. Taking “X rays”
Most of the X rays
pass through the
patient’s body
A photo
graphic
plate is
placed on
the other
side of
the
patient
The patient is placed in
front of a source of X RAYS
10. X-rays are absorbed by bone but can
pass through skin and soft tissuePhotographic
plate
bone
Soft tissue
X rays that are absorbed in the photographic
plate cause chemical changes. These show as
darkened areas when the plate is developed.
11. X-rays are also partly absorbed by some
tissues in the body this creates a more
subtle picture.
Photographic
plate
bone
Soft tissue
12. The
result of the x rays scanner
What part of the body do these X Rays show?
Answer:
A knee
13. Advantages of Basic
X ray Imaging
X
rays are easy to produce
X ray machines are relatively cheap
In controlled doses X ray images are
safe to the patient
14. Disadvantages of X ray Imaging
In large doses X rays can be harmful to health
Images are only “shadow prints” in one
“plane”…..no 3D information
Imaging of soft tissues and organs is not
always very detailed
15. Check Understanding
Answer True or False
1.
2.
3.
X rays are made of the same “stuff” as
visible light. They are both forms of
“electromagnetic radiation”.
X rays were discovered completely by
accident during a physics experiment
carried out in 1965.
X rays can damage healthy tissues.
16. MRI
What do the letters stand for?
M……….. Magnetic
R………… Resonance
I…………. Imaging
MRI scanners do not use X rays.
