RADIOLOGY

NEXT GENERATION SCIENCE / COMMON CORE STANDARDS ADDRESSED! CCSS.ELA-Literacy.RST 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 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.

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; 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; 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.

COMPUTERIZED TOMOGRAPHY - CT

COMPUTERIZED AXIAL TOMOGRAPHY- CAT

MAGNETIC RESONANCE IMAGING / MRI

ULTASOUND

COMPUTER RATIOGRAPHY

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; Lead aprons and gloves when holding and restraining the animal Limit beam size Keep filters in place Keep lead filters in place

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