Current through Reg. 50, No. 249, December 24, 2024
(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 paragraph (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.
New 7-17-85, Amended 3-17-92, 1-5-95, Formerly
10D-91.606.