General Requirements: Diagnostic X-ray Systems
In addition to other requirements of this division, all diagnostic X-ray systems shall meet the following requirements:
Warning Label. The control panel containing the main power switch shall bear the warning statement, legible and accessible to view: “WARNING: This X-ray unit may be dangerous to patient and operator unless safe exposure factors and operating instructions are observed.”
The state shall attach an identification number to each X-ray control panel or an appropriate location:
Identification numbers shall not be removed without written permission of the Authority;
Identification numbers shall not be defaced.
Mobile and portable X-ray systems shall meet the requirements of a stationary system when used for greater than seven consecutive days in the same location.
Battery Charge Indicator. On battery-powered X-ray generators, visual means shall be provided on the control panel to indicate whether the battery is in a state of charge adequate for proper operation.
Leakage Radiation from the Diagnostic Source Assembly. The leakage radiation from the diagnostic source assembly measured at a distance of one meter in any direction from the source shall not exceed 100 mR (25.8 C/kg) in one hour when the X-ray tube is operated at its leakage technique factors. Compliance shall be determined by measurements averaged over an area of 100 square cm with no linear dimension greater than 20 cm.
Radiation from Components Other Than the Diagnostic Source Assembly. The radiation emitted by a component other than the diagnostic source assembly shall not exceed 2 mR (0.516 C/kg) in one hour at 5 cm from any accessible surface of the component when it is operated in an assembled X-ray system under any conditions for which it was designed. Compliance shall be determined by measurements averaged over an area of 100 square cm with no linear dimension greater than 20 cm.
Half-Value Layer (HVL): The HVL of the useful beam for a given X-ray tube potential shall not be less than the values shown in Table 4. If it is necessary to determine such HVL at an X-ray tube potential which is not listed in Table 4, linear interpolation or extrapolation may be made; The referenced table is available on the Program’s website: www.healthoregon.org/rps.
The HVL required in subsection (7)(a) of this rule is considered to have been met if it can be demonstrated that the aluminum equivalent of the total filtration in the primary beam is not less than that shown in Table 5. The referenced table is available on the Program’s website: www.healthoregon.org/rps.
In addition to the requirements of section (5) of this rule, all intraoral dental radiographic systems manufactured on and after December 1, 1980, shall have a minimum HVL not less than 1.5 mm aluminum (Al) equivalent filtration permanently installed in the useful beam;
Beryllium window tubes shall have a minimum of 0.5 mm Al equivalent filtration permanently installed in the useful beam;
For capacitor energy storage equipment, compliance with the requirements of section (5) of this rule shall be determined with the maximum quantity of charge per exposure;
The required minimal aluminum equivalent filtration shall include the filtration contributed by all materials, which are always, present between the source and the patient.
Filtration Controls. For X-ray systems which have variable kVp and variable filtration for the useful beam, a device shall link the kVp selector with the filter(s) and shall prevent an exposure unless the minimum amount of filtration required by subsection (5)(a) of this rule is in the useful beam for the given kVp, which has been selected.
Multiple Tubes. Where two or more radiographic tubes are controlled by one exposure switch, the tube or tubes, which have been selected, shall be clearly indicated prior to initiation of the exposure. This indication shall be both on the X-ray control panel and at or near the tube housing assembly, which has been selected.
Mechanical Support of Tube Head. The tube housing assembly supports shall be adjusted such that the tube housing assembly remains stable during an exposure unless the tube housing movement is a designed function of the X-ray system.
The technique factors to be used during an exposure shall be indicated before the exposure begins. If automatic exposure controls are used, the technique factors, which are set prior to the exposure, shall be indicated;
The requirement of subsection (10)(a) of this rule may be met by permanent marking on equipment having fixed technique factors.
There shall be provided for each X-ray machine a means for determining the proper SID.
X-ray film developing requirements. Compliance with this section is required of all healing arts registrants and is designed to ensure that patient and operator exposure is minimized and to produce optimum image quality and diagnostic information:
Manual processing of films.
The relationship between temperature of the developer and development time indicated in Table 6 or the manufacturer’s recommendations must be used with standard developing chemistry. The referenced table is available on the Program’s website: www.healthoregon.org/rps.
Processing of film. All films shall be processed in such a fashion as to achieve adequate sensitometric performance. This criterion shall be adjudged to have been met if:
Film manufacturer’s published recommendations for time and temperature are followed; or
Each film is developed in accordance with the time-temperature chart (see subsection (12)(a) of this rule).
Chemical-film processing control.
Chemicals shall be mixed in accordance with the chemical manufacturer’s recommendations;
Developer replenisher shall be periodically added to the developer tank based on the recommendations of the chemical or film manufacturer. Solution may be removed from the tank to permit the addition of an adequate volume of replenisher.
All processing chemicals shall be completely replaced at least every two months or as indicated by the manufacturer.
Devices shall be available which will:
Give the actual temperature of the developer; and
Give an audible or visible signal indicating the termination of a preset development time (in minutes or seconds).
Automatic film processing. Films shall be processed in such a manner that the degree of film development is the same as being achieved by proper adherence to subsection (12)(a) of this rule (manual processing).
Darkrooms. Darkrooms shall be constructed so that film being processed, handled, or stored will be exposed only to light which has passed through an appropriate safelight filter.
Safelights shall be mounted in accordance with manufacturer’s recommendations.
Light bulbs used in safelights shall be the type and wattage recommended by the manufacturer.
Safelight lenses shall be the type recommended for use by the film manufacturer.
Rapid film processing. Special chemicals have been designed for use in Endodontics. These chemicals have special development requirements and do not permit as large of a margin of error in darkroom technique as do standard developing chemicals. Failure to precisely follow manufacturer’s recommendations can easily lead to overexposure and underdevelopment. Darkroom procedures shall include:
The manufacturer’s time temperature development is crucial and shall be followed exactly;
Caution: A timer capable of accurately measuring the short development times required shall be used;
If rapid chemical processing is used for general radiography all applicable requirements of section (12) of this rule shall be followed.