Current through Register Vol. 24-18, September 15, 2024
The useful beam shall be limited to the area of clinical
interest and show evidence of collimation. This shall be deemed to have been
met if a positive beam limiting device has been properly used or if evidence of
collimation is shown on at least three sides or three corners of the film, (for
example, projections from the shutters of the collimator, cone cutting at the
corners or a border at the film's edge).
(1)
General purpose stationary and
mobile X-ray systems.
(a) There
shall be provided a means for stepless adjustment of the size of the X-ray
field such that at least two dimensions of the X-ray field are independently
variable. The minimum field size at a SID of 100 centimeters shall be equal to
or less than ten by ten centimeters.
(b) Adequate 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
central axis of the X-ray beam.
(2)
In addition to the requirements
of WAC 246-225-060(1) above all stationary X-ray systems shall meet the following
requirements:
(a) Means shall be
provided to indicate when the axis of the X-ray beam is perpendicular to the
plane of the image receptor and to align the center of the X-ray field with
respect to the center of the image receptor to within 2 percent (5 percent for
equipment manufactured prior to August 1974) of the SID. Dental lateral jaw
examinations shall be excluded from this requirement;
(b) The beam-limiting device shall
numerically indicate the field size in the plane of the image receptor to which
it is adjusted;
(c) Indication of
field size dimensions and SID's shall be specified in inches and/or
centimeters;
(d) Indication of
field size dimensions shall be such that aperture adjustments result in X-ray
field dimensions in the plane of the image receptor to within 2 percent of the
SID when the beam axis is perpendicular to the plane of the image
receptor.
(3)
Radiographic equipment designed for only one image receptor size at a
fixed SID shall be provided with means to limit the field at the plane of the
image receptor to dimensions no greater than those 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.
(4)
Special purpose X-ray
systems.
(a) These systems shall be
provided with means 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) These systems shall be provided with
means to align the center of the X-ray field with the center of the image
receptor to within 2 percent (5 percent for equipment manufactured prior to
August 1974) of the SID.
(c) The
above WAC
246-225-060(4)(a) and 246-225-060(4)(b) may be met with a system that meets the requirements for a general purpose
X-ray system as specified in WAC
246-225-060(1) or, when alignment means are also provided, may be met with either:
(i) 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 and permanent markings to indicate the image
receptor size and SID for which it is designed); or
(ii) A beam-limiting device having multiple
fixed apertures sufficient to meet the requirement 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.
Statutory Authority:
RCW
70.98.050 and
70.98.080. 91-15-083 (Order 183),
§ 246-225-060, filed 7/23/91, effective 8/23/91. Statutory Authority:
RCW
43.70.040. 91-02-049 (Order 121), recodified
as § 246-225-060, filed 12/27/90, effective 1/31/91. Statutory Authority:
RCW
70.98.080. 83-19-050 (Order 2026), §
402-28-051, filed 9/16/83. Statutory Authority:
RCW
70.98.050. 81-01-011 (Order 1570), §
402-28-051, filed 12/8/80; Order 1084, § 402-28-051, filed 1/14/76.
Formerly WAC 402-28-050 (part).
