| (I) For radiation machines that have variable kVp and
variable filtration for the useful beam, a device shall link the kVp
selector with the filters and shall prevent an exposure unless the
minimum amount of filtration required by subparagraph (A) of this
paragraph is in the useful beam for the given kVp that has been selected.
(II) Any other radiation machine having removable filters
shall be required to have the minimum amount of filtration as required
by subparagraph (E)(i)(I) of this paragraph permanently located in
the useful beam during each exposure.
(F) Multiple tubes. Where two or more radiographic
tubes are controlled by one exposure switch, the tube or tubes that
have been selected shall be clearly indicated before initiation of
the exposure. This indication shall be both on the x-ray control panel
and at or near the tube housing assembly that has been selected.
(G) Beam limiting devices.
(i) The beam-limiting device shall provide the same
degree of protection as is required of the housing.
(ii) The numerical SID indicator shall be present and
shall be accurate to within 2.0 percent of the SID for the beam-limiting
device.
(iii) The center of the x-ray field, when perpendicular
to the image receptor, shall be accurate to within plus or minus 2.0
percent of the SID with respect to the center of the image receptor.
(iv) The beam-limiting device shall numerically indicate
the field size in the plane of the image receptor.
(v) Indication of field size dimensions and SIDs shall
be specified in inches or centimeters.
(vi) The field size indicated on the beam-limiting
device shall not exceed 2.0 percent of the SID along the width and
length, separately, of the actual x-ray field size.
(H) Portable x-ray systems. Portable x-ray systems
shall comply with the requirements in subparagraph (G) of this paragraph,
as applicable, based on manufacturer's design.
(I) X-ray control. An x-ray control shall be incorporated
into each x-ray system such that an exposure can be terminated by
the operator at any time except for an exposure of 0.5 seconds or
less or during serial radiography when means shall be provided to
permit completion of any single exposure of the series in process.
(J) Stationary or portable radiation machines. All
stationary or portable radiation machines used for veterinary x-rays
shall be provided with the following:
(i) a continuous pressure type exposure switch; and
(ii) either a six and one-half foot high protective
barrier for operator protection during exposures; or
(iii) a means for the operator to be at least six feet
from the tube housing assembly.
(K) Hand-held portable radiation machines. Operators
using portable radiation machines designed to be hand-held are exempt
from the requirements of paragraph (3)(K) of this subsection. The
hand-held portable radiation machine shall be held only in the manner
specified by the manufacturer. The operator shall wear protective
devices in accordance with paragraph (3)(H) of this subsection.
(L) Portable radiation machines. Portable radiation
machines shall comply with the requirements in subparagraph (H) of
this paragraph, as applicable, based on manufacturer's design.
(M) Radiation machines needing correction or repair.
(i) The correction or repair shall begin within 30
days following the failure and shall be performed according to a plan
designated by the registrant.
(ii) Correction or repair shall be completed no longer
than 90 days from discovery unless authorized in writing by the agency.
(iii) The registrant shall maintain records of corrections
or repairs and any tests, measurements or numerical readings listed
in subsection (j)(5) of this section in accordance with subsection
(k)(2) of this section for inspection by the agency.
(N) Equipment performance evaluations (EPE).
(i) For all radiation machines used in veterinary medicine,
the registrant shall perform, or cause to be performed, EPE tests
for each item specified in clauses (iii) through (vii) of this subparagraph
as follows:
(I) within 30 days after initial installation of radiation
machines:
(II) within 30 days after reinstallation of a radiation
machine;
(III) within 30 days after repair of a radiation machine
component that would affect the radiation output that includes the
timer, tube, and power supply; and
(IV) after initial installation, the EPE tests shall
be performed every 5 years.
(ii) Records of the EPE results shall include the following:
(I) measurements and numerical readings;
(II) indication of pass or fail for each test; and
(III) maintenance by the registrant in accordance with
subsection (k)(2) of this section for inspection by the agency.
(iii) Timer.
(I) The accuracy of the timer shall meet the manufacturer's
specifications. If the manufacturer's specifications are not obtainable,
the timer accuracy shall be plus or minus 10 percent of the indicated
time with testing performed at 0.5 second.
(II) Means shall be provided to terminate the exposure
at a preset time interval, a preset product of current and time, a
preset number of pulses, or a preset radiation exposure to the image
receptor. In addition, 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.
(iv) Kilovolt peak (kVp). The accuracy of the kVp setting
shall meet manufacturer's specifications. If the registrant does not
possess documentation of the appropriate manufacturer's kVp specifications,
the indicated kVp shall be accurate to within plus or minus 10 percent
of the indicated setting(s). For radiation machines with fewer than
three fixed kVp settings, the radiation machine shall be checked at
those settings.
(v) Tube stability. The x-ray tube shall remain physically
stable during exposures. In cases where tubes are designed to move
during exposure, the registrant shall assure proper and free movement
of the radiation machine within manufacturer's specifications.
(vi) Collimation. Field limitation shall meet the requirements
for beam-limiting devices of subparagraph (G) of this paragraph.
(vii) Measurements of the radiation output for a radiographic
x-ray, fluoroscopic, CT, therapeutic machine, simulator, and electronic
brachytherapy device. Measurements for the radiation output of a radiographic
x-ray shall be performed by a registered service provider. Measurements
for the radiation output for a fluoroscopic, CT, and therapeutic,
simulators and electronic brachytherapy devices shall be performed
by licensed medical physicist with a calibrated dosimetry system in
accordance with the following.
(I) The dosimetry system calibration shall be traceable
to a national standard.
(II) Dosimetry systems shall be calibrated within 24
months from the date of the prior calibration.
(III) Measurements of radiation output shall be performed
with a dosimetry system that has been calibrated within the 24 months
preceding the date of the measurement.
(IV) Record of the dosimetry system calibration shall
include:
(-a-) manufacturer's name, model and serial number
of each calibrated instrument;
(-b-) date of the calibration; and
(-c-) name of the individual recording the information.
(viii) Record of dosimetry system calibration. The
registrant shall record the dosimetry system calibration information
specified in clause (vii)(I) - (IV) of this subparagraph and maintain
that record in accordance with subsection (k)(2) of this section for
inspection by the agency.
(6) Additional requirements for fluoroscopic radiation
machines.
(A) Limitation of the useful beam. Limitation of the
useful beam shall be as follows.
(i) Primary barrier.
(I) The fluoroscopic imaging assembly shall be provided
with a primary protective barrier that intercepts the entire cross
section of the useful beam at any SID.
(II) The x-ray tube used for fluoroscopy shall not
produce x-rays unless the barrier is in position to intercept the
useful beam and the imaging device is in place and operable.
(III) The air kerma rate due to transmission through
the barrier with the attenuation block in the useful beam, combined
with radiation through the image intensifier if provided, shall not
exceed 3.34 x 10-3 percent of the entrance
air kerma rate at a distance of 10 cm from any accessible surface
of the fluoroscopic imaging assembly beyond the plane of the image
receptor.
(ii) Measuring compliance of barrier transmission.
Cont'd... |
