Current through Bulletin 2024-06, March 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 meeting the manufacturer's
specifications or the requirements of
R313-28-300
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 of 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) Only x-ray
systems provided with a means for independent stepless adjustment of at least
two dimensions of the x-ray field shall be used.
(b) A method 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
two 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.
(c) The
Board may grant an exemption on non-certified x-ray systems to R313-28-51(1)(a)
and (b) provided the registrant makes a written application for the exemption
and in that application:
(i) demonstrates it
is impractical to comply with R313-28-51(1)(a) and (b); and
(ii) demonstrates the purpose of
R313-28-51(1)(a) and (b) will be met by other methods.
(2) In addition to the
requirements of R313-28-51(1) above, stationary general purpose x-ray systems,
both certified and non-certified shall meet the following requirements:
(a) a method 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 respect to the center of
the image receptor to within two percent of the SID, and to indicate the SID to
within two percent;
(b) the
beam-limiting device shall numerically indicate the field size in the plane of
the image receptor to which it is adjusted; and
(c) indication of field size dimensions and
SID's 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 of the image receptor to within two 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 two percent of the SID, or shall be provided with means to both size and
align the x-ray field so that the x-ray field at the plane of the image
receptor does not extend beyond the edges of the image receptor.
(4) Special purpose x-ray systems.
(a) Means shall be provided to limit the
x-ray field in the plane of the image receptor so that the x-ray field does not
exceed each dimension of the image receptor by more than two 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 two percent of the SID, or means shall be provided to both
size and align the x-ray field so that the x-ray field at the plane of the
image receptor does not extend beyond the edges of the image receptor.
Compliance shall be determined with the axis of the x-ray beam perpendicular to
the plane of the image receptor.
(c)R313-28-51(4)(a) and R313-28-51(4)(b) may
be met with a system that meets the requirements for a general purpose x-ray
system as specified in R313-28-51(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 requirements for the combination of image receptor sizes and SID's for
which the unit is designed with the beam limiting device having 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
the combinations of image receptor sizes and SID's for which the unit is
designed. Permanent, clearly legible markings shall indicate the image receptor
size and SID for which the aperture is designed and shall indicate which
aperture is in position for use.
