1. NUCLEAR PHYSICS
Course Instructor: Dr. Waseem Ahmad
Presentation On: Medical Imaging use radiation
Presented by : Mehak Tariq
Ghazi University DG Khan
3. Introduction:
There are several techniques for producing images
useful for diagnostic purposes.
The study of medical imaging is concerned with all forms
of an images from the observed technology.
Radiation for medical imaging:
The use of an external source of radiation for
medical imaging is of long-standing and well
known. Basically, the system consists of a
source placed some distance in front the patient
and a detector (usually a special type of
sensitive film) placed immediately behind the
patient.
4. Projection X-ray Imaging
the radiation is absorbed according to an exponential law,
a measurement of the intensities just before and after the
patient yields information on the integrated mean free path
of the photons in the body.
ln
𝐼1
𝐼2
=
𝑥1
𝑥2
𝜇 𝑥 𝑑𝑥
X-ray
Source
Object X-ray Detector
m(x,y,z)
Id(x,y)
5. Energy source
incident (x-rays)
Or
Injected (radioactive
material)
Tissue properties
Employed in
Medical imaging
Detection system
e.g. computer,
Radiographic film, etc
Medical image
Interacts,
Penetrates,
Or reflected
Medical images are pictures of tissue characteristics that influence the way
energy is emitted, transmitted, reflected and so on, by the human body.
6. Images can also be
obtained using an internal source of radiation.
This is done by the patient ingesting, or being
injected with, a substance containing a radioactive
𝛾-emitting isotope.
As photon detectors are very sensitive, the
concentration of the radioisotope can be very low
and any risk to the patient is further minimized by
choosing an isotope with a short lifetime.
7. Computed tomography
The term CT stands for " computed tomography"
“A procedure that uses a computer linked to an x-
ray machine to make a series detailed pictures of
areas inside the body.”
Tomography scan allows doctors to see inside the
body. It uses a combination of x- ray and
computer to create pictures of organs,bones,and
other tissues. It shows more details than regular
x- ray
8. We can get CT scan on
any part of body How
does computed
tomography work.
The term CT refers to a
computerized X- ray
imaging procedure in
which narrow beam of x-
ray is aimed at patient
and quickly rotated
around the body
producing signals that
are processed by
machines .computer to
create cross sectional
images or slices of body.
9. Uses:
The most commonly
performed CT scan is of
brain, to determine the
cause of stroke or assess
serious head injuries .To
detect the abnormalities in
the body such as tumors
,abnormal blood vessels etc.