Radiographic and Ultrasonographic Techniques

Chapter 4 Radiographic and Ultrasonographic Techniques


Milliampere-Second and Kilovolt Peak



Intensifying Screens

The screen is a suspension of phosphor crystals in a binder. The phosphor in the screen converts x-ray photons into visible light, to which the film is more sensitive. A latent image is created by exposure of the film to this light. This technique reduces x-ray exposure to the patient by at least 10 times and the time of x-ray exposure, thus decreasing the chance of blurring.


Radiographic film provides a permanent record containing the maximum amount of diagnostic information.

Miscellaneous Accessories


Type of Contrast Agent Brand Names Manufacturers
Barium products Intropaste (barium paste) Lafayette Pharmacal (Lafayette, IN)
Barosperse (barium suspension) Mallinckrodt (St. Louis, MO)
Novopaque (barium suspension) Lafayette Pharmacal (Lafayette, IN)
E-Z-ML- 196 (barium suspension) E-Z-EM (Westbury, NY)
Iodinated gastrointestinal contrast agent Gastrografin Bracco Diagnostics (New Brunswick, NJ)
Omnipaque (iohexol) Amersham Health (Piscataway, NJ)
Iodinated contrast agent Renografin 60 or 76 Bracco Diagnostics (New Brunswick, NJ)
Hypaque-76 Amersham Health (Piscataway, NJ)
Conray 30 or 400 Mallinckrodt (St. Louis, MO)
Myelographic contrast agent Omnipaque (iohexol) Amersham Health (Piscataway, NJ)
Isovue (iopamidol) Bracco Diagnostics (New Brunswick, NJ)


Exposure Timer Check (Single-Phase Machine)

Use a spinning-top test tool. It can be purchased from the same company as the machine (see Table 4-1) or from an accessory company (see Table 4-3). This tool is inexpensive ($50) and easy to use. It is a flat metal spinning top with a hole in one side. The top is set on a loaded cassette and spun. Take an exposure at 1/120 second. Move the top to another corner of the film, spin again, and expose at 1/60 second. This maneuver is repeated at 1/40 and 1/30 second. At 1/120 second, only one dot should be seen; at 1/60, two dots; at 1/40, three dots; and at 1/30, four dots. If more or less dots are on the film than expected, the timer is not accurate.


Manual Processing

Film developing is a chemical process and therefore depends on both time and temperature.

Procedure for Manual Film Processing


Automatic Processing



Darkroom layout (Figs. 4-1 and 4-2): Darkrooms do not have to take up much room but are at least 6 × 8 feet. Many darkrooms are located where a bathroom might have been. This eliminates the process of bringing in new plumbing and electrical outlets. Try to include a sink for cleanup and processor maintenance. Keep wet and dry areas separate to eliminate contamination of screens and unexposed film by chemicals. Always have good ventilation to keep heat, humidity, and chemical fumes from destroying film and to reduce exposure of personnel to chemical fumes. Paint all walls white to reflect light from the safelights and for a brighter working environment. Use an adequate number and type of safelights. Make sure all safelights are 40 inches from the working area to prevent film fogging.


Aug 27, 2016 | Posted by in SMALL ANIMAL | Comments Off on Radiographic and Ultrasonographic Techniques

Full access? Get Clinical Tree

Get Clinical Tree app for offline access