Chapter 31 Quality Control
Two areas of activity are designed to
ensure the best possible image quality
with the lowest possible exposure and
Quality Assurance deals with people
Quality Control deals with instrumentation
Week 10 A Magnetic
Material from Clinical Imaging with
Skeletal, Chest and Abdomen
by Dennis M. Marchiori
Magnetic Resonance Imaging
Developed from Nuclear Magnetic
Resonance used in laboratories to
Other Factors that Impact Detail
The Relative Speed Value of the screens and film used. Screen and Film Contact Patient motion Processing of Image
Relative Speed Value of Film System
The higher relative speed value systems will produce less sharp images
Chapter 40 Radiation
ALARA and Occupational
ALARA stands for As Low As Reasonably
Achievable. It is the basic principle of radiation
There is much that we can do to keep exposure
to the patient
When the x-ray beam is produced, many energies of photons exist. Many are of such low energies that they will offer nothing to the production of the radiograph. Metals such as aluminum will absorb the soft low energy rays. This reduces t
Chapter 37 Radiation and
Pregnancy and Genetic Effects
From the first medical application of x-rays, there
has been a concern and apprehension regarding
the effects of radiation before, during and after
Before pregnancy- concerns about fertil
Chapter 37 Late Effects of
The early effects of radiation exposure are
produced by high radiation doses.
The radiation exposure from diagnostic
radiology are low level and of low LET.
They are chronic in nature because they
are delivered inte
Kilovolt Peak (kVp)
kVp determine the quality of the beam. X-ray penetration is governed by the kVp setting. kVp controls the contrast of the radiographic image. Contrast is the difference in density of adjacent structures on the image.
Kilovolt Peak (
Chapter 36 Early Effects of
In the 1920s & 1930s if was not
uncommon for radiologic technologist to
get hematologic exams weekly.
Blood work was used to monitor the
worker for over exposure before
dosimeters were available.
In the 1960s blood
Chapter 34 Principles of
In 1906, two French scientists, Bergonie
and Tribondeau, theorized and observed
that radiosensitivity was a function of the
metabolic state of the tissue being
irradiated. There observations became the
Law of Bergon
Chapter 33 Radiobiology
Radiobiology is the study of the effects of
ionizing radiation on biologic tissues.
The ultimate goal of research is to develop
dose-response relationships so the effects
of planned doses can be predicted and the
response to acci
Chapter 19 & 20 Image Quality
There are three geometric factors that
affect radiographic quality.
Focal Spot Blur
We have explored these factors in the
All objects on the radiograph are
Chapter 18 Radiographic Exposure
Exposure Factors influence and determine
the quantity and quality of the x-radiation
to which the patient is exposed.
Radiation quantity refers to the radiation
intensity referred to as mR or mR/ mAs.
Radiographic Image Quality
Image visibility or the Photographic Properties Density: The overall blackness of the image. Contrast: the difference between adjacent densities on a radiograph.
If the image is too dark, it has too much density. If
Chapters 29 & 30 Computed
Godfrey Hounsfield of EMI, LTD
demonstrated the principle for computed
tomography in 1970.
Alan Cormack developed the mathematics
used to reconstruct the CT images.
They shared the 1982 Nobel Prize for
Chapter 16 Beam-Restricting
Three factors contribute to an increase in
Increased Field Size
Increased Patient or Body Part Size.
a some interact with the
patient and are scattered
Chapter 15 Radiographic Intensifying
Screens And Cassettes
There are three key parts of the Image
Receptor for Conventional Radiography:
Film to record the image
Intensifying Screens to expose the film
Cassette to protect the screens and film
Shape distortion is the misrepresentation of the object compared to the image. Most shape distortion is the result of angulation of the tube or film. This can be beneficial.If we can move overlying anatomy or open disc spaces, shape dist
Chapter 13 Radiographic Film
Remnant Radiation: the x-rays that
interact with the x-ray film.
Few of the original x-rays actually make
the image. The remnant radiation is the
image forming radiation that passes
completely through the patient.
Types of X
Chapter 12 X-ray Interaction with
Electromagnetic Radiation interacts with
structures with similar size to the
wavelength of the radiation.
Interactions have wavelike and particle like
X-rays have a very small wavelength, no
Chapter 10 X-ray Production &
Chapter 11 X-ray Emissions
Electron- Anode Interaction
Imagine the energy needed to propel electron
from 0 to half the speed of light in one to three
The electrons that travel from the cathode to
the anode are
Impact of SID and OFD on Image Quality
We usually want to get the body part as close to the film as possible to reduce magnification distortion.
Impact of SID and OFD on Image Quality
When we cant get the part close to the film, the SID should be increa
Chapter 9 The X-ray Machine
The x-ray machine is divided into four
The Operating Console
The High Voltage Section
The Film Holder , Grid Cabinet or Table
Chiropractic X-ray Room
Floor mounted x-ray
Wall grid c
Chapter 8 The Console
The Console is the part of the machine
that the operator controls the operation of
the x-ray machine.
All machine console are a little different
but there are always similarities. The
console is where we control x-ray tube
Chapter 6 Electricity and Chapter
Two types of energy are important to Xray.
The function of the x-ray machine is to
convert electrical energy to
Electricity and Magneti
Element of Image Sharpness
Recorded detail is the
sharpness of the lines
of the image.
Distortion is the
of the true size or
shape of the image
compared to the
What impacts the recorded
Focal spot size
Object to Im
Chapter 5 Electromagnetic
A photon is the smallest element of
Photons are energy disturbances moving
through space at the speed of light.
Photons have no mass but they do have
electric and magnetic fields.
Chapter 3 Fundamentals of Physics
& Chapter 4 The Atom
Physics is the study of the interaction of
matter & energy.
Physicist strive for simplicity. There are
three base quantities.
Base Quantities Support
LC232 X-ray Physics &
Russell L. Wilson C.R.T.
Week 1a Chapter 1 Concepts
of Radiologic Science
Everything in the universe can be
classified as matter or energy.
Matter is anything that occupies space
and has a shape or form.
X-ray Principles & Physics Laboratory
Russell L. Wilson , CRT, RT(R)
Properties of X-ray
X-rays travel in a straight line and diverge from their point of origin. X-ray photons have many different energies. X-rays are highly penetrating. X-rays are invisi