Chapter 17 Flashcards
Radiology
X rays were discovered in 1895 by scientist, wilhelm Conrad Roentgen. While with a divece called Crooke’s tube, which generated cathode rays.
The first dental radiograph was taken during 1895 by Dr. Otto Walkoff. Within 10 years the discovery of x-rays were being used for diagnosis of medical and dental conditions.
x-rays travel in straight lines at the speed of light
They affect photographic film by producing a hidden image made visible by processing
They cause certain substances to fluorece (glow)
They cause irritaion of living cells in large amounts can cause necrosis (death) of the cell, a fact that necessitates caution in using x-rays
X-rays are produced in the x-ray tube head when a metal tungsten target is bombarded by a stream of electrons.
the x-rays are sent from the x-ray machine the cone head, through the patient and then reach the x-ray cassette to produce an image on the film.
the density of the x-ray image is controlled by kVp, exposure time, mA and target-film distance
the measurement of this wave motion is called a wavelength. The wavelength for xrays is extremely short in comparison to electromagnetice rays which are longer.
ALARA stands for “As Low As Reasonably Achievable”
X-ray room behind the
technician’s protective lead-lined barrier or at
least 6 feet from the tube head
Film badges
are used to monitor scatter (stray) radiation that
occurs in the Radiology department.
Xray film log will contain name rank SSN unit assigned and reason for xray and number of exposures taken and settings if possible
Bio effects of radiation are loss of hair, redness and inflammation of the skin , blood count change, cell atrophy wasting away. ulcerations, serility, genetic damage, cancer, leukemia, and DEATH.
Precious Metals Recovery Program
The precious metals recovery program is
designated to save Department of Defense
(DOD) money by recycling precious metals and
using those funds to offset the cost of supplies
for DOD activities. Both lead and silver are
precious metals found in all x-ray departments.
Lead is found in X-ray tube packets, floor
coverings, wall shielding, patient shields, and xray
packets. Silver is found in used fixer
solutions and medical/dental films. Precious
metals will be saved and turned into the Supply
Department following the guidelines in
BUMEDINST 4010.3, Precious Metals
Recovery Program
DENTAL: The wrong angulation results in a distorted radiograph.
Too little vertical angulation elongates the xray image
Too much vertical angulation foreshortens the image.
Maxillary xrays the patients head is tilted downward
Mandibular xrays the head is tiled upward
Mandibular molars the xrays are horizontal 0 degrees
Change the developer and fixer at a
minimum of once every 3 to 4 weeks. If a large
quantity of X-rays has been processed, change
the developer sooner. Replenish the solutions
following the manufacturer’s instructions.
Herringbone image is the wrong side of the film is facing the source of the xray beam during exposure
Full mouth Periapical mounting contains 14 slots for PAs and 2 slots for interproximal bitewings
END
the Nuclear Regulatory Commission (NRC) monitors the use of ionizing radiation
Title 10, Part 20, of the Code of Federal Regulations (10 CFR Part 20), “Standards for Protection Against Radiation.” It sets the annual total effective dose limit at 5,000 mRem (5 Rem) for the entire body.
