Current through Bulletin 2024-06, March 15, 2024
Diagnostic x-ray systems incorporating one or more certified
components shall be required to comply with the following additional
requirements which relate to the certified component.
(1) Beam limitation for stationary and mobile
general purpose x-ray systems.
(a) There
shall be provided a means of stepless adjustment of the size of the x-ray
field. The minimum field size at an SID of 100 centimeters shall be equal to or
less than five centimeters by five centimeters.
(b) When a light localizer is used to define
the x-ray field, it shall provide an average illumination of not less than 160
LUX (15 foot-candles) at 100 centimeters or at the maximum SID, whichever is
less. The average illumination shall be based upon measurements made in the
approximate center of the quadrants of the light field. Radiation therapy
simulation systems are exempt from this requirement.
(2) Beam Limitation for Portable X-ray
Systems. Beam limitation for portable x-ray systems shall meet the additional
field limitation requirements of
R313-28-51(1)
or R313-28-300(1).
(3) Beam
limitation and alignment on stationary general purpose x-ray systems equipped
with PBL.
(a) PBL shall prevent the
production of x-rays when:
(i) either the
length or the width of the x-ray field in the plane of the image receptor
differs, except as permitted by R313-28-300(3)(c), from the corresponding image
receptor dimensions by more than three percent of the SID; or
(ii) the sum of the length and width
differences as stated in R313-28-300(3)(a)(i) without regard to sign exceeds
four percent of the SID.
(b) Compliance with R313-28-300(3)(a) shall
be determined when the equipment indicates that the beam axis is perpendicular
to the plane of the image receptor. Compliance shall be determined no sooner
than five seconds after insertion of the image receptor.
(c) The PBL system shall be capable of
operation, at the discretion of the operator, so that the field size at the
image receptor can be adjusted to a size smaller than the image receptor
through stepless adjustment of the field size. The minimum field size at a
distance of 100 centimeters shall be equal to or less than five centimeters by
five centimeters.
(d) The PBL
system shall be designed so that if a change in image receptor does not cause
an automatic return to PBL function as described in R313-28-300(3)(a), then
change of the image receptor size or SID must cause the automatic
return.
(4) Tube Stands
for Portable X-Ray Systems. A tube stand or other mechanical support shall be
used for portable x-ray systems, so that the x-ray tube housing assembly need
not be hand-held during exposures.
