General Consideration of all imaging Modalities

General Consideration of all
Imaging Modalities
Muhammad Arif Afridi
Lecturer In Medical Imaging
Email: drarifafridi@gmail.com
MUHAMMAD ARIF AFRIDI | LECTURER IN MEDICAL IMAGING | DRARIFAFRIDI@GMAIL.COM 1

Definitions:
Radiology: The science dealing with X-rays and other high-energy radiation, especially the use
of such radiation for the diagnosis and treatment of disease.
X-rays: X-rays are a form of electromagnetic radiation that can pass through objects, including
the body.
X-rays penetrate different objects more or less according to their density.
In medicine, X-rays are used to view images of the bones and other structures in the body.
Radiation: Energy emitted and transferred through matter.

Introduction
 Radiology is the science dealing with X-rays and other high-energy radiation, especially the
use of such radiation for the diagnosis and treatment of disease.
 General Radiography, commonly referred to as X-ray.
 X-ray is an important diagnostic tool and was the first established modality of Diagnostic
Imaging.
 X-rays are used to create images of the body's internal structures.
 These images are used to detect abnormalities in bones, lungs and other internal organs

Radiation
Energy emitted and transferred through space is called
radiation.
Radiation is the transfer of energy.
Ionizing radiation is a special type of radiation that
includes x-rays. Ionizing radiation is any type of radiation
that is capable of removing an orbital electron from the
atom with which it interacts.
interaction between radiation and matter is called
ionization.

Continue…
Ionization occurs when an x-ray passes close to an orbital electron of an atom and transfers
sufficient energy to the electron to remove it from the atom.
The ionizing radiation may interact with and ionize additional atoms.
The orbital electron and the atom from which it was separated are called an ion pair.
The electron is a negative ion, and the remaining atom is a positive ion.
Any type of energy that is capable of ionizing matter is known as ionizing radiation.

Continue…
Matter that intercepts radiation and absorbs part or all of it is said to be exposed or irradiated.
Spending a day at the beach exposes you to ultraviolet light, causes sunburn.
During a radiographic examination, the patient is exposed to x-rays. The patient is said to be
irradiated.

Sources of Ionizing Radiation
divided into two main categories:
◦ natural environmental radiation
◦ man-made radiation
Natural environmental radiation results in an annual dose of approximately 3 millisieverts (mSv).
Man-made radiation results in 3.2 mSv annually.
An mSv is the unit of effective dose.

Discovery Of X-rays
Wilhelm Roentgen, a German professor of physics, was the first
person to discover electromagnetic radiation in a wavelength
range commonly known as X-rays today.
For his remarkable achievement he was honored with the first
Nobel Prize in Physics in 1901.

Discovery of X-ray Beams
Wilhelm Roentgen was already working on the effects of cathode rays during 1895, before he
actually discovered X-rays. His experiments involved the passing of electric current through
gases at extremely low pressure. On November 8, 1895 while he was experimenting, he
observed that certain rays were emitted during the passing of the current through discharge
tube. His experiment that involved working in a totally dark room with a well covered
discharge tube resulted in the emission of rays which illuminated a barium platinocyanide
covered screen. The screen became fluorescent even though it was placed in the path of the
rays, two meters away from discharge tube.
He continued his experiments using photographic plate to capture the image of various objects
of random thickness placed in the path of the rays. He generated the very first
"roentgenogram" by developing the image of his wife's hand and analyzed the variable
transparency as showed by her bones, flesh and her wedding ring. Based on his subsequent
research and experiments, he declared that X-ray beams are produced by the impact of
cathode rays on material objects.

Crookes Tube
The type of Crookes tube Roentgen used when
he discovered x-rays.
Cathode rays (electrons) leaving the cathode
are attracted by high voltage to the anode,
where they produce x-rays and fluorescent
light.
(Courtesy Gary Leach, Memorial Hermann Hospital.)

First Radiograph
The hand shown in this radiograph belongs to
Mrs. Roentgen.
This first indication of the possible medical
applications of x-rays was made within a few
days of the discovery.
(Courtesy Deutsches Roentgen Museum.)

Energy
Energy emitted and transferred through space is called radiation.
When a piano string vibrates, it is said to radiate sound; the sound is a form of radiation.
Ripples or waves radiate from the point where a pebble is dropped into a still pond.
Visible light, a form of electromagnetic energy, is radiated by the sun and is electromagnetic
radiation.
Electromagnetic energy is usually referred to as electromagnetic radiation or, simply, radiation.
Radiation is the transfer of energy.

Basic Radiation Protection
 Always practice ALARA: Keep radiation exposures as low as reasonably achievable.
 Filtration
 Collimation
 Protective Apparel
 Gonadal Shielding
 Protective Barriers

Ten Commandments of Radiation Protection
1. Understand and apply the cardinal principles of radiation control: time, distance, and shielding.
2. Do not allow familiarity to result in false security.
3. Never stand in the primary beam.
4. Always wear protective apparel when not behind a protective barrier.
5. Always wear an occupational radiation monitor and position it outside the protective apron at the collar.
6. Never hold a patient during radiographic examination. Use mechanical restraining devices when possible.
Otherwise, have family or friends hold the patient.
7. The person who is holding the patient must always wear a protective apron and, if possible, protective gloves.
8. Use gonadal shields on all people of childbearing age when such use will not interfere with the examination.
9. Examination of the pelvis and lower abdomen of pregnant patients should be avoided whenever possible,
especially during the first trimester.
10. Always collimate to the smallest field size appropriate for the examination.

Radiologic Units
1. Air kerma (Gya) is the unit of radiation
exposure
2. The gray (Gyt) is the unit of radiation
absorbed dose (rad).
3. The sievert (Sv) is the unit of occupational
radiation exposure and effective dose.
4. The becquerel (Bq) is the unit of
radioactivity.

Special Quantities of Radiologic Science and Their Associated Special Units

Radiologic Technologist
A radiologic technologist can specialize in many
types of imaging modalities.

Uses of X-rays
The most common form of X-ray used is X-ray radiography, which can be used to help detect or diagnose:
Bone fractures
Infections (such as pneumonia)
Calcifications (like kidney stones or vascular calcifications)
Some tumors
Arthritis in joints
Bone loss (such as osteoporosis)
Dental issues
Heart problems (such as congestive heart failure)
Blood vessel blockages
Digestive problems
Foreign objects (such as items swallowed by children)

Radiology Modalities
1. Radiography (X-ray)
2. Fluoroscopy
3. Computed Tomography (CT)
4. Magnetic Resonance Imaging (MRI)
5. Ultrasound

Radiography (X-ray)
X-ray machine provide a static image on
radiograph.
X-ray or radiography uses a very small dose of
ionizing radiation to produce pictures of the
body's internal structures.
X-rays are the oldest and most frequently used
form of medical imaging.
They are often used to help diagnosed fractured
bones, look for injury or infection and to locate
foreign objects in soft tissue.
20MUHAMMAD ARIF AFRIDI | LECTURER IN MEDICAL IMAGING | DRARIFAFRIDI@GMAIL.COM

Fluoroscopy
Fluoroscopy is based on x-rays.
X-ray tube is installed
The radiation dose is higher than Radiography.
Provide both static and dynamic images.

Computerized Tomography (CT) scan
A computerized tomography (CT) scan
combines a series of X-ray images taken from
different angles and
uses computer processing to create cross-
sectional images, or slices, of the bones, blood
vessels and soft tissues inside your body.
CT scan images provide more detailed
information than plain X-rays do.
CT scan can be used to visualize nearly all
parts of the body and is used to diagnose
disease or injury as well as to plan medical,
surgical or radiation treatment.

Magnetic resonance imaging (MRI)
Magnetic resonance imaging (MRI) is a
type of scan that uses strong magnetic
fields and radio waves to produce detailed
images of the inside of the body.
An MRI scanner is a large tube that
contains powerful magnets. You lie inside
the tube during the scan.

Ultrasound
Ultrasound is a type of imaging.
It uses high-frequency sound waves to look at
organs and structures inside the body.
Health care professionals use it to view the
heart, blood vessels, kidneys, liver, and other
organs.

Thank you!

General Consideration of all imaging Modalities

Recomendados

Recomendados

Mais conteúdo relacionado

Mais procurados

Mais procurados (20)

Semelhante a General Consideration of all imaging Modalities

Semelhante a General Consideration of all imaging Modalities (16)

Mais de Muhammad Arif Afridi

Mais de Muhammad Arif Afridi (17)

Último

Último (20)

General Consideration of all imaging Modalities