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RADIOLOGY
NEXT GENERATION SCIENCE / COMMON CORE
STANDARDS ADDRESSED!
• CCSS.ELA-Literacy.RST.11-12.2 Determine the central ideas or conclusions of a text;
summarize complex concepts, processes, or information presented in a text by para
CCSS.ELA-Literacy.
• RST.11-12.3 Follow precisely a complex multistep procedure when carrying out
experiments, taking measurements, or performing technical tasks; analyze the
specific results based on explanations in the text phrasing them in simpler but still
accurate terms.
AGRICULTURE, FOOD, AND NATURAL
RESOURCE STANDARDS ADDRESSED
• AS.07.01. Design programs to prevent animal diseases, parasites and other
disorders and ensure animal welfare.
• AS.07.01.01.a. Identify and summarize specific tools and technology used in
animal health management.
BELL WORK
• Describe the safety precautions that should be observed when performing
an x-ray.
• How should lead gloves and aprons be stored?
• Describe the steps for determining the machine settings for a radiograph.
• What is a grid and what is its purpose.
TERMS!
• Anterior
• Computerized Axial Tomography
• Computerized Tomography
• Digital Radiography
• Dorsal
• Magnetic Resonance Imaging
• Posterior
• Ultrasound
• Vacuum Tube
• Ventral
INTRODUCTION
• Veterinarians view radiographic imaging as their most important diagnostic
tool.
• The veterinary assistant generally serves a role in the radiographic process.
• The Vet Assistant must understand terms, equipment and the process in
producing quality images.
• The radiographic process continues to improve with techniques such as
computer enhancement becoming common place.
• The better the image quality, the easier the diagnosis.
X – RAY PRODUCTION
• An x-ray tube is a vacuum tube
containing a metal target onto
which a beam of electrons is
directed at high energy for the
production of x-rays.
• The vacuum tube has an emitter
which establishes a flow of
electrical current know as a beam.
• A high power electrical power
source accelerates the electrons.
• The electrical flow collides with a
target.
KILOVOLTAGE PEAK
• Kilovoltage peak (kVp) refers to the maximum value of the applies x-ray tube
voltage during x ray production.
• The following variables will impact the x-ray signal;
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Penetrability
Number of x-ray photons produced
Frequency
Energy
Wavelength
• Radiation will change as it pass through tissue with
some radiation absorbed by soft tissue. These
changes may affect the image.
• Increasing the kVp increases the number o
photons produced and increases the penetration
of the x-ray. This could lead to black x rays.
• Decreasing the kVp causes fewer photons to
reach the target and yields x rays that appear to
be under – exposed to light.
• Always remember to adjust beam intensity as you
move closer for further away from the patient.
• Generally most small animal images are taken at
40 inches. Decreasing the distance will reduce the
patients exposure to radiation.
• X ray scatter control is very important. Filtration and collimation devices area
installed on x ray housing to decrease exposure to scatter radiation.
X RAY GRID
• The purpose of the x ray grid is to eliminate scattered radiation from hitting
the image receptor.
• The x ray grid is a filtering unit made primarily of lead and strips of radiolucent
materials.
• X ray beam intensity may be adjusted according to the grid size.
DETERMINING MACHINE SETTINGS
• X ray technique chart.
RADIOGRAPHIC POSITIONS
• Generally x rays are taken from at least two views.
• The vet. Assistant needs to be familiar with normal positions used for
radiography. Generally the second x ray will be at a 90 degree angle from
the first image.
• Normal views used;
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Dorsal – top
Ventral – lower
Anterior – front
Posterior – rear
• Lateral always refers to an outer view while medial refers to an inner view.
METHODS OF IMAGING
• Imaging in modern veterinary clinics is not limited to x-ray alone, numerous other
imaging processes are now available to todays generation of veterinarians.
Computerized Axial Tomography – CAT scan – computerized 3D images
Magnetic Resonance Imaging – MRI- magnetic field and radio wave create images
Ultrasound – Uses high frequency sound waves to create an image
Computerized tomography – CT- uses x rays for cross sectional imaging
Computer Radiography – CR- similar to standard x – ray but an imaging plate
connected to a laser scanner for a digital image is used rather than a lead plate.
• Digital Radiography – DR – a form of x ray where a digital x ray sensor is used instead
of traditional photographic film.
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COMPUTERIZED TOMOGRAPHY - CT
COMPUTERIZED AXIAL
TOMOGRAPHY- CAT
MAGNETIC RESONANCE IMAGING / MRI
ULTRASOUND
COMPUTER RADIOGRAPHY
DIGITAL RADIOGRAPHY
TISSUE DENSITY – ITS IMPACT ON
RADIOGRAPHIC IMAGES.
• The typical radiographic image is composed of black, white and shades of
gray.
• Black represents air and air filled areas.
• Grey indicates soft tissue, and fluid.
• White will represent bone.
X RAY SAFETY PRECAUTIONS!
• The x ray operator needs to be aware that excessive exposure to x rays is
dangerous.
• Only licensed operators should be using radiographic equipment.
• Excessive exposure to x rays may be dangerous.
• Safety precautions should include;
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Lead aprons and gloves when holding and restraining the animal
Limit beam size
Keep filters in place
Keep lead filters in place
THE END !