64E-5.505. Diagnostic Radiography Systems, Other than Fluoroscopic, Mammographic, Dental Intraoral or Veterinary Systems

(1) Beam Limitation. The useful beam shall be limited to the area of clinical interest.

(a) General Purpose Stationary and Mobile X-Ray Systems.

1. A means for stepless adjustment of the size of the x-ray field shall be provided.

2. Means shall be provided for visually defining the perimeter of the x-ray field. The total misalignment of the edges of the visually defined field with the respective edges of the x-ray field along either the length or width of the visually defined field shall not exceed 2 percent of the distance from the source to the center of the visually defined field when the surface upon which it appears is perpendicular to the axis of the x-ray beam.

3. Mobile x-ray systems shall be equipped with an attached rule to accurately measure the SID at any distance up to 72 inches (183 cm).

(b) Stationary general purpose diagnostic x-ray systems shall be equipped with the following additional features:

1. Positive means shall be provided to indicate when the axis of the x-ray beam is perpendicular to the plane of the image receptor; to align the center of the x-ray field with the center of the image receptor to within 2 percent of the SID; and to indicate the SID to within 2 percent.

2. The beam-limiting device shall numerically indicate the field size in the plane of the image receptor to which it is adjusted.

3. Indication of field size dimensions and SIDs shall be specified in inches or centimeters, and shall be such that aperture adjustments result in x-ray field dimensions in the plane of the image receptor which correspond to those indicated by the beam limiting device to within 2 percent of the SID when the beam axis is perpendicular to the plane of the image receptor.

(c) X-Ray Systems Used for One Image Receptor Size. Radiographic equipment used for only one image receptor size shall have a fixed SID and shall be provided with positive means to limit the x-ray field at the plane of the image receptor to the area of the image receptor, and to align the center of the x-ray field with the center of the image receptor to within 2 percent of the SID.

(d) Special Purpose X-Ray Systems.

1. For x-ray systems with more than one image receptor size,

a. Means shall be provided to limit the x-ray field in the plane of the image receptor so that such field does not exceed each dimension of the image receptor by more than 2 percent of the SID when the axis of the x-ray beam is perpendicular to the plane of the image receptor.

b. Means shall be provided to align the center of the x-ray field with the center of the image receptor to within 2 percent of the SID, or means shall be provided to both size and align the x-ray field such that the x-ray field at the plane of the image receptor does not extend beyond any edge of the image receptor.

2. The requirements in this paragraph are met by a system that meets the requirements for a general purpose x-ray system as specified in (1)(a), above, or, when positive alignment means are also provided, may be met with either:

a. An assortment of removable, fixed-aperture, beam-limiting devices sufficient to meet the requirement for each combination of image receptor size and SID for which the unit is designed; each such device shall have clear markings to indicate the image receptor size and SID for which it is designed; or

b. A beam-limiting device having multiple fixed apertures sufficient to meet the requirements for each combination of image receptor size and SID for which the unit is designed. Permanent, clearly legible markings shall indicate the image receptor size and SID for which each aperture is designed and shall indicate which aperture is in position for use.

(2) Radiation Exposure Control Devices.

(a) Timers. Means shall be provided to terminate the exposure at a preset time interval, preset product of current and time (mAs), a preset number of pulses, or a preset radiation exposure to the image receptor.

1. Except for dental panoramic systems, termination of exposure shall cause automatic resetting of the timer to its initial setting or to 0.

2. It shall not be possible to make an exposure when the timer is set to a zero or off position, if either position is provided.

(b) X-Ray Exposure Control Switch Type and Location.

1. A control of the dead-man type shall be incorporated into each x-ray system such that an exposure will be terminated at any time pressure is released from the switch, except during serial radiography, when means have been provided to permit completion of any single exposure of the series in progress.

2. Each x-ray control shall be located in such a way as to meet the following requirements:

a. The operator’s station at the control panel shall be behind a protective barrier so positioned that leakage radiation and once scattered radiation will be intercepted.

b. For panoramic dental units with intensifying screens and a beam stop, the operator shall stand at least 4 feet (1.25 m) from the patient and the tube head or behind a protective barrier during exposures.

c. The operator’s protective barrier shall be equipped with a window or mirror system so arranged that the operator may keep the patient under constant visual surveillance during exposures. The window shall have lead equivalent shielding equal to that required in the operator’s protective barrier.

d. Each exposure switch, except those used in conjunction with fluoroscopic spot film devices and movable protective barriers, shall be securely fixed so that the operator cannot conveniently make exposures from an unshielded position.

e. Provision shall be made for aural communication with the patient from the control panel.

f. Mobile and portable x-ray systems which are:

(I) Used continually in a single location for a period greater than 1 week shall be considered a stationary radiographic system and shall meet the requirements for such an installation.

(II) Used at multiple locations shall be provided either with an adequate protective barrier or protective apron for the operator and with a method of control which will permit the operator to be at least 12 feet (3.75 m) from the tube head and the nearest edge of the useful beam during exposures.

3. The x-ray control shall provide a visual indication observable from the operator’s protected position whenever x-rays are produced.

4. A sound audible to the operator shall indicate that the exposure has terminated or is in progress.

(3) Source-to-Skin Distance Limitations. All mobile or portable radiographic systems shall be provided with a positive means to limit the source-to-skin distance to not less than 30 centimeters.

(4) Standby Radiation from Capacitor Energy Storage Equipment. Radiation emitted from the x-ray tube when the exposure switch or timer is not activated shall not exceed a rate of 2 milliroentgens (0.516 mC per kg) per hour at 5 centimeters from any accessible surface of the diagnostic source assembly, with the beam-limiting device fully open.

(5) Intracavitary X-Ray Systems. Use of intracavitary x-ray systems on humans is prohibited unless specific approval has been granted by the Department. Application for such use must include evidence attesting to the exclusive advantages to be gained in the use of intracavitary radiographic techniques as opposed to conventional radiographic procedures.

Rulemaking Authority 404.051, 404.141, 404.22 FS. Law Implemented 404.022, 404.051(1), (4), (6), 404.141, 404.22(1), (3) FS. History–New 7-17-85, Amended 3-17-92, 1-5-95, Formerly 10D-91.606.