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ream is perpendicular to the plane of the mage receptor, and compliance shall be determined with the beam axis indicated to be perpendicular to the plane of the image reeptor.

(3) The center of the x-ray field in the plane of the image receptor shall be aligned with the center of the selected portion of the mage receptor to within 2 percent of the SID.

(4) Means shall be provided to reduce the xay field size in the plane of the image recepor to a size smaller than the selected porsion of the image receptor such that:

(i) For spot-film devices used on fixed-SID luoroscopic systems which are not required to, and do not provide stepless adjustment of the x-ray field, the minimum field size, at the greatest SID, does not exceed 125 square m; or (ii) For spot-film devices used on luoroscopic systems that have a variable SID and/or stepless adjustment of the field size, the minimum field size, at the greatest SID, shall be containable in a square of 5 cm by 5 cm.

(5) A capability may be provided for overriding the automatic x-ray field size adjustment in case of system failure. If it is so provided, a signal visible at the fluoroscopist's position shall indicate whenever the automatic x-ray field size adjustment override is engaged. Each such system failure override switch shall be clearly labeled as follows: For X-ray Field Limitation System Failure

(i) Source-skin distance-(1) X-ray systems designed for use with an intraoral image receptor shall be provided with means to limit the source-skin distance to not less than:

(i) Eighteen cm if operable above 50 kVp; or (ii) Ten cm if not operable above 50 kVp.

(2) Mobile and portable X-ray systems other than dental shall be provided with means to limit the source-skin distance to not less than 30 cm.

(j) Beam-on indicators. The x-ray control shall provide visual indication whenever xrays are produced. In addition, a signal audible to the operator shall indicate that the exposure has terminated.

(k) Multiple tubes. Where two or more radiographic tubes are controlled by one exposure switch, the tube or tubes which have been selected shall be clearly indicated before initiation of the exposure. This indication shall be both on the x-ray control and at or near the tube housing assembly which has been selected.

(1) Radiation from capacitor energy storage equipment. Radiation emitted from the x-ray tube shall not exceed:

(1) An air kerma of 0.26 microGy (vice 0.03 MR exposure) in 1 minute at 5 cm from any accessible surface of the diagnostic source assembly, with the beam-limiting device

fully open, the system fully charged, and the exposure switch, timer, or any discharge mechanism not activated. Compliance shall be determined by measurements averaged over an area of 100 square cm, with no linear dimension greater than 20 cm; and

(2) An air kerma of 0.88 mGy (vice 100 mR exposure) in 1 hour at 100 cm from the x-ray source, with the beam-limiting device fully open, when the system is discharged through the x-ray tube either manually or automatically by use of a discharge switch or deactivation of the input power. Compliance shall be determined by measurements of the maximum air kerma per discharge multiplied by the total number of discharges in 1 hour (duty cycle). The measurements shall be averaged over an area of 100 square cm with no linear dimension greater than 20 cm.

(m) Primary protective barrier for mammography x-ray systems-(1) For x-ray systems manufactured after September 5, 1978, and before September 30, 1999, which are designed only for mammography, the transmission of the primary beam through any image receptor support provided with the system shall be limited such that the air kerma 5 cm from any accessible surface beyond the plane of the image receptor supporting device does not exceed 0.88 microGy (vice 0.1 mR exposure) for each activation of the tube.

(2) For mammographic x-ray systems manufactured on or after September 30, 1999:

(i) At any SID where exposures can be made, the image receptor support device shall provide a primary protective barrier that intercepts the cross section of the useful beam along every direction except at the chest wall edge.

(ii) The x-ray system shall not permit exposure unless the appropriate barrier is in place to intercept the useful beam as required in paragraph (m)(2)(i) of this section.

(iii) The transmission of the useful beam through the primary protective barrier shall be limited such that the air kerma 5 cm from any accessible surface beyond the plane of the primary protective barrier does not exceed 0.88 microGy (vice 0.1 mR exposure) for each activation of the tube.

(3) Compliance with the requirements of paragraphs (m)(1) and (m)(2)(iii) of this section for transmission shall be determined with the x-ray system operated at the minimum SID for which it is designed, at the maximum rated peak tube potential, at the maximum rated product of x-ray tube current and exposure time (mAs) for the maximum rated peak tube potential, and by measurements averaged over an area of 100 square cm with no linear dimension greater than 20 cm. The sensitive volume of the radiation measuring instrument shall not be positioned beyond the edge of the primary protective barrier along the chest wall side. 70 FR 34036, June 10, 2005]

$ 1020.32 Fluoroscopic equipment.

vided that it shall not be closer than 30 The provisions of this section apply

centimeters. Movable grids and comto equipment for fluoroscopy and for

pression devices shall be removed from the recording of images through an

the useful beam during the measureimage intensifier except computed to

ment. For all measurements, the atmography x-ray systems manufactured

tenuation block shall be positioned in on or after November 29, 1984.

the useful beam 10 centimeters from (a) Primary protective barrier—(1) Limi the point of measurement of entrance tation of useful beam. The fluoroscopic exposure rate and between this point imaging assembly shall be provided and the input surface of the with a primary protective barrier fluoroscopic imaging assembly. which intercepts the entire cross sec- (b) Field limitation—(1) Nonimage-intion of the useful beam at any SID. The tensified fluoroscopy. (i) The x-ray field X-ray tube used for fluoroscopy shall produced by nonimage-intensified not produce x-rays unless the barrier is fluoroscopic equipment shall not exin position to intercept the entire use- tend beyond the entire visible area of ful beam. The exposure rate due to the image receptor. Means shall be protransmission through the barrier with vided for stepless adjustment of the the attenuation block in the useful field size. The minimum field size, at beam combined with radiation from the greatest SID, shall be containable the image intensifier if provided, shall in a square of 5 centimeters by 5 centinot exceed 3.34x10-3 percent of the en- meters. trance exposure rate, at a distance of (ii) For equipment manufactured 10 centimeters from any accessible sur

after February 25, 1978, when the angle face of the fluoroscopic imaging assem

between the image receptor and the bly beyond the plane of the image re

beam axis of the x-ray beam is variceptor. Radiation therapy simulation

able, means shall be provided to indisystems shall be exempt from this re

cate when the axis of the x-ray beam is quirement provided the systems are in

perpendicular to the plane of the image tended only for remote control oper

receptor. Compliance with paragraph ation and the manufacturer sets forth

(b)(1)(i) of this section shall be deterinstructions for assemblers with re

mined with the beam axis indicated to spect to control location as part of the information required in $ 1020.30(g). Ad

be perpendicular to the plane of the ditionally, the manufacturer shall pro

image receptor. vide to users, pursuant to

(2) Image-intensified fluoroscopy. (i) $ 1020.30(h)(1)(i), precautions concerning

For image-intensified fluoroscopic the importance of remote control oper

equipment other than radiation theration.

apy simulation systems, neither the (2) Measuring compliance. The en

length nor the width of the x-ray field trance exposure rate shall be measured

in the plane of the image receptor shall in accordance with paragraph (d) of

exceed that of the visible area of the this section. The exposure rate due to

image receptor by more than 3 percent transmission through the primary bar

of the SID. The sum of the excess rier combined with radiation from the length and the excess width shall be no image intensifier shall be determined greater than 4 percent of the SID. by measurements averaged over an (ii) For rectangular x-ray fields used area of 100 square centimeters with no with circular image receptors, the linear dimension greater than 20 centi- error in alignment shall be determined meters. If the source is below the table along the length and width dimensions top, the measurement shall be made of the x-ray field which pass through with the input surface of the the center of the visible area of the fluoroscopic imaging assembly posi- image receptor. tioned 30 centimeters above the table (iii) For equipment manufactured top. If the source is above the tabletop after February 25, 1978, when the angle and the SID is variable, the measure- between the image receptor and beam ment shall be made with the end of the axis is variable, means shall be probeam-limiting device or spacer as close vided to indicate when the axis of the to the tabletop as it can be placed, pro- x-ray beam is perpendicular to the

plane of the image receptor. Compli- (1) Equipment with automatic exposure ance with paragraph (b)(2)(i) of this rate control (AERC). Fluoroscopic equipsection shall be determined with the ment that is provided with AERC shall beam axis indicated to be perpen- not be operable at any combination of dicular to the plane of the image recep tube potential and current that will retor.

sult in an exposure rate in excess of (iv) Means shall be provided to per- 2.58x10–3 coulomb per kilogram (C/kg) mit further limitation of the field. per minute (10 roentgens per minute (10 Beam-limiting devices manufactured R/min)) at the point where the center after May 22, 1979, and incorporated in of the useful beam enters the patient, equipment with a variable SID and/or except: the capability of a visible area of (i) During recording of fluoroscopic greater than 300 square centimeters images, or shall be provided with means for

(ii) When an optional high-level constepless adjustment of the x-ray field.

trol is provided. When so provided, the Equipment with a fixed SID and the ca

equipment shall not be operable at any pability of a visible area of no greater combination of tube potential and curthan 300 square centimeters shall be

rent that will result in an exposure provided with either stepless adjust

rate in excess of 1.29x10-3 C/kg per ment of the x-ray field or with a means

minute (5 R/min) at the point where to further limit the x-ray field size at

the center of the useful beam enters the plane of the image receptor to 125

the patient, unless the high-level consquare centimeters or less. Stepless ad

trol is activated. Special means of actijustment shall, at the greatest SID,

vation of high-level controls shall be provide continuous field sizes from the

required. The high-level control shall maximum obtainable to a field size

be operable only when continuous mancontainable in a square of 5 centi

ual activation is provided by the opermeters by 5 centimeters.

ator. A continuous signal audible to (3) If the fluoroscopic x-ray field size

the fluoroscopist shall indicate that is adjusted automatically as the SID or

the high-level control is being emimage receptor size is changed, a capa

ployed. bility may be provided for overriding

(2) Equipment without AERC (manual the automatic adjustment in case of

mode). Fluoroscopic equipment that is system failure. If it is so provided, a

not provided with AERC shall not be signal visible at the fluoroscopist's po

operable at any combination of tube sition shall indicate whenever the

potential and current that will result automatic field adjustment is over

in an exposure rate in excess of ridden. Each such system failure over

1.29x10-3 C/kg per minute (5 R/min) at ride switch shall be clearly labeled as

the point where the center of the useful follows:

beam enters the patient, except:

(i) During recording of fluoroscopic For X-ray Field Limitation System

images, or Failure

(ii) When an optional high-level con

trol is activated. Special means of acti(c) Activation of tube. X-ray produc- vation of high-level controls shall be tion in the fluoroscopic mode shall be required. The high-level control shall controlled by a device which requires be operable only when continuous mancontinuous pressure by the operator for ual activation is provided by the operthe entire time of any exposure. When ator. A continuous signal audible to recording serial fluoroscopic images, the fluoroscopist shall indicate that the operator shall be able to terminate the high-level control is being emthe x-ray exposure(s) at any time, but ployed. means may be provided to permit com (3) Equipment with both an AERC mode pletion of any single exposure of the se- and a manual mode. Fluoroscopic equipries in process.

ment that is provided with both an (d) Entrance exposure rates. For AERC mode and a manual mode shall fluoroscopic equipment manufactured not be operable at any combination of before May 19, 1995, the following re- tube potential and current that will requirements apply:

sult in an exposure rate in excess of 2.58x10-3 C/kg per minute (10 R/min) in centimeters to the centerline of the xeither mode at the point where the cen- ray table. ter of the useful beam enters the pa- (5) Exemptions. Fluoroscopic raditient except:

ation therapy simulation systems are (i) During recording of fluoroscopic exempt from the requirements set images, or

forth in paragraph (d) of this section. (ii) When the mode or modes have an (e) Entrance erposure rate limits. For optional high-level control, in which fluoroscopic equipment manufactured case that mode or modes shall not be on and after May 19, 1995, the following operable at any combination of tube requirements apply: potential and current that will result (1) Fluoroscopic equipment operable in an exposure rate in excess of at any combination of tube potential 1.29x10-3 C/kg per minute (5 R/min) at and current that results in an exposure the point where the center of the useful rate greater than 1.29x10-3 C/kg per beam enters the patient, unless the minute (5 R/min) at the point where high-level control is activated. Special the center of the useful beam enters means of activation of high-level con- the patient shall be equipped with trols shall be required. The high-level AERC. Provision for manual selection control shall be operable only when of technique factors may be provided. continuous manual activation is pro- (2) Fluoroscopic equipment shall not vided by the operator. A continuous be operable at any combination of tube signal audible to the fluoroscopist shall potential and current that will result indicate that the high-level is being in an exposure rate in excess of employed.

2.58x10-3 C/kg per minute (10 R/min) at (4) Measuring compliance. Compliance the point where the center of the useful with paragraph (d) of this section shall beam enters the patient except: be determined as follows:

(i) During the recording of images (i) If the source is below the x-ray from an X-ray image-intensifier tube table, the exposure rate shall be meas, using photographic film or a video ured at 1 centimeter above the tabletop camera when the x-ray source is operor cradle.

ated in a pulsed mode. (ii) If the source is above the x-ray (ii) When an optional high-level contable, the exposure rate shall be meas- trol is activated. When the high-level ured at 30 centimeters above the table control is activated, the equipment top with the end of the beam-limiting shall not be operable at any combinadevice or spacer positioned as closely tion of tube potential and current that as possible to the point of measure will result in an exposure rate in excess ment.

of 5.16x10-3 C/kg per minute (20 R/min) (iii) In a C-arm type of fluoroscope, at the point where the center of the the exposure rate shall be measured at useful beam enters the patient. Special 30 centimeters from the input surface means of activation of high-level conof the fluoroscopic imaging assembly, trols shall be required. The high-level with the source positioned at any control shall only be operable when available SID, provided that the end of continuous manual activation is prothe beam-limiting device or spacer is vided by the operator. A continuous no closer than 30 centimeters from the signal audible to the fluoroscopist shall input surface of the imaging assembly indicate that the high-level control is

(iv) In a lateral type of fluoroscope, being employed. the exposure rate shall be measured at (3) Measuring compliance, Compliance a point 15 centimeters from the center with paragraph (e) of this section shall line of the x-ray table and in the direc- be determined as follows: tion of the x-ray source with the end of (i) If the source is below the X-ray the beam-limiting device or spacer po- table, the exposure rate shall be meassitioned as closely as possible to the ured at 1 centimeter above the tabletop point of measurement. If the tabletop or cradle. is movable, it shall be positioned as (ii) If the source is above the x-ray closely as possible to the lateral x-ray table, the exposure rate shall be meassource, with the end of the beam-lim- ured at 30 centimeters above the tableiting device or spacer no closer than 15 top with the end of the beam-limiting

device or spacer positioned as closely as possible to the point of measurement.

(iii) In a C-arm type of fluoroscope, the exposure rate shall be measured at - 30 centimeters from the input surface of the fluoroscopic imaging assembly, with the source positioned at any available SID, provided that the end of the beam-limiting device or spacer is no closer than 30 centimeters from the input surface of the fluoroscopic imaging assembly.

(iv) In a lateral type of fluoroscope, - the exposure rate shall be measured at E a point 15 centimeters from the center- line of the x-ray table and in the direction of the x-ray source with the end of the beam-limiting device or spacer po- sitioned 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 15 centimeters to the centerline of the xray table.

(4) Eremptions. Fluoroscopic radiation therapy simulation systems are exempt from the requirements set forth in paragraph (e) of this section.

(f) Indication of potential and current. During fluoroscopy

and cinefluorography, x-ray tube potential and current shall be continuously indicated. Deviation of x-ray tube potential and current from the indicated values shall not exceed the maximum deviation as stated by the manufacturer in accordance with $ 1020.30(h)(3).

(g) Source-skin distance. Means shall be provided to limit the source-skin distance to not less than 38 centimeters on stationary fluoroscopes and to not less than 30 centimeters on mobile and portable fluoroscopes. In addition, for image-intensified fluoroscopes intended for specific surgical application that would be prohibited at the source-skin distances specified in this paragraph, provisions may be made for operation at shorter source-skin distances but in no case less than 20 centimeters. When provided, the manufacturer must set forth precautions with respect to the optional means of spacing, in addition to other information as required in g 1020.30(h).

(h) Fluoroscopic timer. Means shall be provided to preset the cumulative ontime of the fluoroscopic tube. The maximum cumulative time of the timing device shall not exceed 5 minutes without resetting. 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. As an alternative to the requirements of this paragraph, radiation therapy simulation systems may be provided with a means to indicate the total cumulative exposure time during which X-rays were produced, and which is capable of being reset between x-ray examinations.

(i) Mobile and portable fluoroscopes. In addition to the foregoing requirements of this section, mobile and portable fluoroscopes shall provide intensified imaging. (58 FR 26404, May 3, 1993, as amended at 59 FR 26404, May 19, 1994)

EFFECTIVE DATE NOTE: At 70 FR 34039, June 10, 2005, $ 1020.32 was revised, effective June 10, 2006. For the convenience of the user, the revised text is set forth as follows:

$ 1020.32 Fluoroscopic equipment.

The provisions of this section apply to equipment for fluoroscopic imaging or for recording images from the fluoroscopic image receptor, except computed tomography X-ray systems manufactured on or after November 29, 1984.

(a) Primary protective barrier(1) Limitation of useful beam. 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. The x-ray tube used for fluoroscopy shall not produce x-rays unless the barrier is in position to intercept the entire useful beam. The AKR due to transmission through the barrier with the attenuation block in the useful beam combined with radiation from the fluoroscopic image receptor shall not exceed 3.34x10-3 percent of the entrance AKR, at a distance of 10 cm from any accessible surface of the fluoroscopic imaging assembly beyond the plane of the image receptor. Radiation therapy simulation systems shall be exempt from this requirement provided the systems are intended only for remote control operation and the manufacturer sets forth instructions for assemblers with respect to control location as part of the information required in $1020.30(g). Additionally, the manufacturer shall provide to users, under

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