Current through Register Vol. 48, No. 9, September 27, 2024
In addition to the applicable provisions of this regulation,
the requirements of this Part apply to all stationary, transportable, mobile,
portable, and C-Arm type fluoroscopes. All fluoroscopic x-ray systems shall be
image intensified or direct digital receptor, and meet the following
requirements.
4.9.1 Source-to-Skin
Distance (SSD). The SSD shall not be less than:
4.9.1.1 Thirty-eight centimeters (38 cm) on
stationary and transportable fluoroscopic systems manufactured on or after
August 1, 1974;
4.9.1.2 Thirty-five
and one half centimeters (35.5 cm) on stationary and transportable fluoroscopic
systems manufactured prior to August 1, 1974;
4.9.1.3 Thirty centimeters (30 cm) on all
mobile and portable fluoroscopes; and
4.9.1.4 Twenty centimeters (20 cm) for mobile
fluoroscopes used for specific surgical procedures. If removable, the
appropriate spacer shall be replaced after the specific surgical procedure
application is complete.
4.9.1.4.1 For
stationary, transportable, mobile, or portable fluoroscopes manufactured on or
after June 10, 2006, having a maximum source-to-image receptor distance of less
than forty-five centimeters (45 cm), means shall be provided to limit the
source-to-skin distance (SSD) to not less than nineteen centimeters (19 cm).
Such systems shall be labeled for extremity use only.
4.9.1.4.2 For those systems intended for
specific surgical applications that would be prohibited at the source-skin
distance specified above, provisions may be made for operation at shorter
source-skin distances but in no case less than ten centimeters (10
cm).
4.9.2
Limitation of Useful Beam.
4.9.2.1 Primary
Barrier
4.9.2.1.1 The fluoroscopic imaging
assembly shall be provided with a primary protective barrier which intercepts
the entire cross section of the useful beam at any SID.
4.9.2.1.2 The x-ray tube used for fluoroscopy
shall not produce x-rays unless the barrier is in position to intercept the
entire useful beam.
4.9.2.2 X-ray field. Neither the length nor
the width of the x-ray field in the plane of the image receptor shall exceed
that of the visible area of the image receptor by more than three percent (3%)
of the SID. The sum of the excess length and the excess width shall be no
greater than four percent (4%) of the SID. In addition:
4.9.2.2.1 Means shall be provided to permit
further limitation of the x-ray field. Beam-limiting devices manufactured after
May 22, 1979, and incorporated in equipment with a variable SID and/or a
visible area of greater than three hundred square centimeters (300
cm2) shall be provided with means for stepless
adjustment of the x-ray field;
4.9.2.2.2 All equipment with a fixed SID and
a visible area of three hundred square centimeters (300
cm2) or less shall be provided with either stepless
adjustment of the x-ray field or with means to further limit the x-ray field
size at the plane of the image receptor to one hundred twenty-five square
centimeters (125 cm2) or less. Stepless adjustment
shall, at the greatest SID, provide continuous field sizes from the maximum
obtainable to a field size of five centimeters by five centimeters (5 cm x 5
cm) or less.
4.9.2.2.3 For
equipment manufactured after February 25, 1978, when the angle between the
image receptor and beam axis is variable, means shall be provided to indicate
when the axis of the x-ray beam is perpendicular to the plane of the image
receptor.
4.9.2.2.4 Compliance
shall be determined with the beam axis indicated to be perpendicular to the
plane of the image receptor. For rectangular x-ray fields used with circular
image reception, the error in alignment shall be determined along the length
and width dimensions of the x-ray field which pass through the center of the
visible area of the image receptor.
4.9.2.2.5 For uncertified image-intensified
fluoroscopic equipment with a spot film device, the x-ray beam with the
shutters fully opened (during fluoroscopy or spot filming) shall be no larger
than the largest spot film size for which the device is designed. Measurements
shall be made at the minimum SID available but at no less than twenty
centimeters (20 cm) table top to the film plane distance.
4.9.2.3 Spot film devices which are certified
components shall meet the following additional requirements.
4.9.2.3.1 Means shall be provided between the
source and the patient for adjustment of the x-ray field size in the plane of
the film to the size of that portion of the film which has been selected on the
spot film selector. Such adjustment shall be automatically accomplished except
when the x-ray field size in the plane of the film is smaller than that of the
selected portion of the film. For spot film devices manufactured after June 21,
1979, if the x-ray field size is less than the size of the selected portion of
the film, the means for adjustment of the field size shall be only at the
operator's option.
4.9.2.3.2 Spot
film field size. Neither the length nor the width of the x-ray field in the
spot film plane shall exceed the image receptor by more than three percent (3%)
of the SID. The sum of the excess length and the excess width shall be no
greater than four percent (4%) of the SID.
4.9.2.3.3 It shall be possible to adjust the
x-ray field size in the plane of the film to a size smaller than the selected
portion of the film. The minimum field size at the greatest SID shall be equal
to, or less than, five centimeters by five centimeters (5 cm x 5 cm).
4.9.2.3.4 The center of the x-ray field in
the plane of the film shall be aligned with the center of the selected portion
of the film to within two percent (2%) of the SID.
4.9.2.3.5 On spot-film devices manufactured
after February 25, 1978, if the angle between the plane of the image receptor
and beam axis is variable, means shall be provided to indicate when the axis of
the x-ray beam is perpendicular to the plane of the image receptor, and
compliance shall be determined with the beam axis indicated to be perpendicular
to the plane of the image receptor.
4.9.3 Activation of the Fluoroscopic Tube.
X-ray production in the fluoroscopic mode shall be controlled by a device which
requires continuous pressure by the fluoroscopist for the entire time of any
exposure. When recording serial fluoroscopic images, the fluoroscopist shall be
able to terminate the x-ray exposure(s) at any time, but means may be provided
to permit completion of any single exposure of the series in process.
4.9.4 Exposure Rate Limits. Entrance Exposure
Rate Allowable Limits.
4.9.4.1 For equipment
manufactured prior to May 19, 1995:
4.9.4.1.1
Equipment with automatic exposure rate control. Fluoroscopic equipment which is
provided with automatic exposure rate control shall not be operable at any
combination of tube potential and current which will result in an exposure rate
in excess of ten Roentgens (10 R)(2.58 mC/kg) per minute at the point where the
center of the useful beam enters the patient, except:
4.9.4.1.1.1 During recording of fluoroscopic
images, or
4.9.4.1.1.2 When an
optional high level control is provided. When so provided, the equipment shall
not be operable at any combination of tube potential and current which will
result in an exposure rate in excess of five Roentgens (5 R)(1.29 mC/kg) per
minute at the point where the center of the useful beam enters the patient
unless the high level control is activated. Special means of activation of high
level control shall be required. The high level control shall only be operable
when continuous manual activation is provided by the operator. A continuous
signal audible to the fluoroscopist shall indicate that the high level control
is being employed.
4.9.4.1.2 Equipment without automatic
exposure rate control. Fluoroscopic equipment which is not provided with
automatic exposure rate control shall not be operable at any combination of
tube potential and current which will result in an exposure rate in excess of
five Roentgens (5 R)(1.29 mC/kg) per minute at the point where the center of
the useful beam enters the patient, except:
4.9.4.1.2.1 During recording of fluoroscopic
images, or
4.9.4.1.2.2 When an
optional high level control is activated. Special means of activation of high
level controls shall be required. The high level control shall only be operable
when continuous manual activation is provided by the operator. A continuous
signal audible to the fluoroscopist shall indicate that the high level control
is being employed.
4.9.4.2 For equipment manufactured after May
19, 1995:
4.9.4.2.1 Equipment with automatic
exposure rate control. Fluoroscopic equipment which is provided with automatic
exposure rate control shall not be operable at any combination of tube
potential and current which will result in an exposure rate in excess of ten
Roentgens (10 R)(2.58 mC/kg) per minute at the point where the center of the
useful beam enters the patient, except:
4.9.4.2.1.1 During recording of fluoroscopic
images, or
4.9.4.2.1.2 When an
optional high level control is provided. When so provided, the equipment shall
not be operable at any combination of tube potential and current which will
result in an exposure rate in excess of twenty Roentgens (20 R)(5.16 mC/kg) per
minute at the point where the center of the useful beam enters the patient when
the high level control is activated. Special means of activation of high level
control shall be required. The high level control shall only be operable when
continuous manual activation is provided by the operator. A continuous signal
audible to the fluoroscopist shall indicate that the high level control is
being employed.
4.9.4.2.2 Equipment without automatic
exposure control. Fluoroscopic equipment which is not provided with automatic
exposure rate control shall not be operable at any combination of tube
potential and current which will result in an exposure rate in excess of five
Roentgens (5 R)(1.29 mC/kg) per minute at the point where the center of the
useful beam enters the patient, except:
4.9.4.2.2.1 During recording of fluoroscopic
images, or
4.9.4.2.2.2 When an
optional high level control is provided. When so provided, the equipment shall
not be operable at any combination of tube potential and current which will
result in an exposure rate in excess of twenty Roentgens (20 R)(5.16 mC/kg) per
minute at the point where the center of the useful beam enters the patient when
the high level control is activated. Special means of activation of high level
control shall be required. The high level control shall only be operable when
continuous manual activation is provided by the operator. A continuous signal
audible to the fluoroscopist shall indicate that the high level control is
being employed.
4.9.4.3 Compliance with
RHB 4.9.4.1 and 4.9.4.2
shall be determined as follows:
4.9.4.3.1 If
the source is below the x-ray table, the exposure rate shall be measured one
centimeter (1 cm) above the tabletop or cradle.
4.9.4.3.2 If the source is above the x-ray
table, the exposure rate shall be measured at thirty centimeters (30 cm) above
the tabletop with the end of the beam-limiting device or spacer positioned as
closely as possible to the point of measurement.
4.9.4.3.3 In a C-arm type of fluoroscope, the
exposure rate shall be measured thirty centimeters (30 cm) from the input
surface of the fluoroscopic imaging assembly.
4.9.4.3.4 For a variable SID C-arm type of
fluoroscope the exposure rate shall be measured thirty centimeters (30 cm) from
the input surface of the fluoroscopic imaging assembly, with the end of the
beam-limiting device or spacer positioned as close as possible to the point of
measurement.
4.9.4.3.5 In a C-arm
type of fluoroscope having an SID less than forty-five centimeters (45 cm), the
exposure rate shall be measured at the minimum SSD.
4.9.4.3.6 In a lateral type fluoroscope, the
exposure rate shall be measured at a point fifteen centimeters (15 cm) from the
centerline of the x-ray table and in the direction of the x-ray source with the
end of the beam-limiting device or spacer positioned as closely as possible to
the point of measurement. If the tabletop is movable, it shall be positioned as
closely as possible to the lateral x-ray source, with the end of the
beam-limiting device or spacer no closer than fifteen centimeters (15 cm) to
the centerline of the x-ray table.
4.9.4.3.7 Conditions of measurement of
maximum entrance exposure rate are as follows:
4.9.4.3.7.1 The measurement shall be made
under the conditions that satisfy the requirements of
RHB 4.9.4.3.
4.9.4.3.7.2 The kVp, mA, and other selectable
parameters shall be adjusted to those settings which give the maximum entrance
exposure rate.
4.9.4.3.7.3 The
x-ray system that incorporates automatic exposure rate control shall have
sufficient attenuative material placed in the useful beam to produce the
maximum output of that system.
4.9.4.3.7.4 Testing shall be performed in
each mode used clinically.
4.9.4.3.8 Conditions of measurement of
typical entrance exposure rate are as follows:
4.9.4.3.8.1 The measurement shall be made
under the conditions that satisfy the requirements of
RHB 4.9.4.3.
4.9.4.3.8.2 The kVp and mA shall be typical
of clinical use of the x-ray system.
4.9.4.3.8.3 The x-ray system(s) that
incorporates automatic exposure rate control shall have sufficient attenuative
material placed in the useful beam to produce a milliAmpere and/or kiloVoltage
typical of the use of the x-ray system.
4.9.4.3.8.4 Testing shall be performed in
each mode used clinically.
4.9.5 Barrier Transmitted Radiation Rate
Limits. The exposure rate due to transmission through the primary protective
barrier with the attenuation block in the useful beam, combined with radiation
from the image intensifier, shall not exceed two milliRoentgen (2 mR)(0.516
uC/kg) per hour at ten centimeters (10 cm) from any accessible surface of the
fluoroscopic imaging assembly beyond the plane of the image receptor for each
Roentgen per minute of entrance exposure rate.
4.9.5.1 Measuring Compliance of Barrier
Transmission.
4.9.5.1.1 The exposure rate due
to transmission through the primary protective barrier combined with radiation
from the image intensifier shall be determined by measurements averaged over an
area of one hundred square centimeters (100 cm2)
with no linear dimension greater than twenty centimeters (20 cm).
4.9.5.1.2 If the source is below the
tabletop, the measurement shall be made with the input surface of the
fluoroscopic imaging assembly positioned thirty centimeters (30 cm) above the
tabletop.
4.9.5.1.3 If the source
is above the tabletop and the SID is variable, the measurement shall be made
with the end of the beam-limiting device or spacer as close to the tabletop as
it can be placed, provided that it shall not be closer than thirty centimeters
(30 cm).
4.9.5.1.4 Compression
devices shall be removed from the useful beam during the measurement.
4.9.6 Indication of
Potential and Current. During fluoroscopy and cinefluoroscopy the kV and mA
shall be continuously indicated.
4.9.7 Fluoroscopic Timer.
4.9.7.1 Means shall be provided to preset the
cumulative on-time of the fluoroscopic x-ray tube. The maximum cumulative time
of the timing device shall not exceed five (5) minutes without
resetting.
4.9.7.2 A signal audible
to the fluoroscopist shall indicate the completion of any preset cumulative
on-time. Such signal shall continue to sound while x-rays are produced until
the timing device is reset.
4.9.8 Control of Scattered Radiation.
4.9.8.1 Fluoroscopic table designs when
combined with procedures utilized shall be such that no unprotected part of any
staff or ancillary individual's body shall be exposed to unattenuated scattered
radiation which originates from under the table. The attenuation required shall
be not less than 0.25 millimeter lead equivalent.
4.9.8.2 Equipment configuration when combined
with procedures shall be such that no portion of any staff or ancillary
individual's body, except the extremities, shall be exposed to the unattenuated
scattered radiation emanating from above the tabletop unless that individual:
4.9.8.2.1 Is at least one hundred twenty
centimeters (120 cm) from the center of the useful beam, or
4.9.8.2.2 The radiation has passed through
not less than 0.25 millimeter lead equivalent material including, but not
limited to, drapes, bucky-slot cover panel, or self-supporting curtains, in
addition to any lead equivalency provided by the protective apron referred to
in RHB
4.2.9.2.
4.9.8.3 The Department may grant exemptions
to RHB
4.9.8.2.2 where a sterile field will not permit the
use of the normal protective barriers. Automatic exemptions will be granted for
fluoroscopic procedures listed in Appendix E.
4.9.9 Spot-Filming Procedures. Fluoroscopic
x-ray systems equipped with a spot-film device must meet the following
requirements for spot-film procedures:
4.9.9.1
Timers. Means shall be provided to terminate the exposure at a preset time
interval, 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 (0)" or "off"
position if either position is provided.
4.9.9.2 Timer Reproducibility. With a timer
setting of one-half (0.5) second or less, the average exposure period (T) shall
be greater than or equal to five (5) times the maximum exposure period (Tmax)
minus the minimum exposure period (Tmin) when four (4) timer tests are
performed: T >= 5 (Tmax - Tmin).
4.9.9.3 Exposure Reproducibility. The
coefficient of variation of exposure shall not exceed 0.05 when all selectable
technique factors are held constant. This requirement shall be deemed to have
been met if, when four exposures are made at identical technique factors, the
value of the average exposure (E) is greater than or equal to five (5) times
the maximum exposure (Emax) minus the minimum exposure (Emin): E >= 5 (Emax
- Emin).
4.9.10 Mobile
and Portable fluoroscopic x-ray systems which are used in a single location for
a period of greater than four (4) consecutive days shall be considered a
stationary fluoroscopic system, and shall meet all the requirements of
RHB 4.4.
4.9.11 Radiation Therapy Simulation Systems.
Radiation therapy simulation systems shall be exempt from all the requirements
of RHB
4.9.2, 4.9.4, 4.9.5, and 4.9.7 provided that:
4.9.11.1 Such systems are designed and used
in such a manner that no individual other than the patient is in the x-ray room
during periods of time when the system is producing x-rays, unless the
procedure requires the presence of other individuals.
4.9.11.2 Systems which do not meet the
requirements of
RHB 4.9.7 are provided with a
means of indicating the cumulative time that an individual patient has been
exposed to x-rays. Procedures shall require in such cases that the timer be
reset between examinations.
4.9.12 Fluoroscopic Quality Assurance. In
addition to the requirements of
RHB 4.2.16, the fluoroscopic
image resolution shall be tested as part of the quality assurance program. This
shall be performed at least annually.
4.9.13 Vertical Fluoroscopic Imaging Systems.
4.9.13.1 SSD. The SSD shall not be less than
thirty-eight centimeters (38 cm).
4.9.13.2 Limitation of Useful Beam. All
provisions of
RHB 4.9.2 apply.
4.9.13.3 Entrance Exposure Rates. All
provisions of
RHB 4.9.4 apply.
4.9.13.4 Activation of the Fluoroscopic Tube.
X-ray production in the fluoroscopic mode shall be controlled by a device which
requires continuous pressure by the fluoroscopist for the entire time of any
exposure. When recording serial fluoroscopic images, the fluoroscopist shall be
able to terminate the x-ray exposure(s) at any time, but means may be provided
to permit completion of any single exposure of the series in process.
4.9.13.5 Indication of Potential and Current.
During fluoroscopy and cinefluorography the kV and mA shall be continuously
indicated.
4.9.13.6 Fluoroscopic
Timer.
4.9.13.6.1 Means shall be provided to
preset the cumulative on-time of the fluoroscopic x-ray tube. The maximum
cumulative time of the timing device shall not exceed five (5) minutes without
resetting.
4.9.13.6.2 A signal
audible to the fluoroscopist shall indicate the completion of any preset
cumulative on-time. Such signal shall continue to sound while x-rays are
produced until the timing device is reset.
4.9.13.7 Operators shall remain in a
protected area during exposures, or shall be protected by aprons of not less
than 0.25 millimeter lead equivalent material.
4.9.13.8 Spot-Filming Procedures.
Fluoroscopic x-ray systems equipped with a spot-film device must meet the
following requirements for spot-film procedures:
4.9.13.8.1 Timers. Means shall be provided to
terminate the exposure at a preset time interval, 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 (0)" or "off position if either position is
provided.
4.9.13.8.2 Timer
Reproducibility. With a timer setting of one-half (0.5) second or less, the
average exposure period (T) shall be greater than or equal to five (5) times
the maximum exposure period (Tmax) minus the minimum exposure period (Tmin)
when four (4) timer tests are performed: T >= 5(Tmax - Tmin).
4.9.13.8.3 Exposure Reproducibility. The
coefficient of variation of exposure shall not exceed 0.05 when all technique
factors are held constant. This requirement shall be deemed to have been met
if, when four exposures are made at identical technique factors, the value of
the average exposure (E) is greater than or equal to five (5) times the maximum
exposure (Emax) minus the minimum exposure (Emin): E >= 5(Emax -
Emin).