Section 33.1-10-06-05 - Fluoroscopic x-ray systemsAll fluoroscopic x-ray systems shall be image-intensified and meet the following requirements:
1.Limitation of useful beam.a. Primary barrier. (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 source-image receptor distance (SID).(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.b. X-ray field. (1) For certified fluoroscopic systems with or without a spot-film device, 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 of the source-image receptor distance. The sum of the excess length and the excess width shall be no greater than four percent of the source-image receptor distance.(2) For uncertified fluoroscopic systems 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 maximum source-image distance available but at no less than twenty centimeters tabletop to the film plane distance.(3) For uncertified fluoroscopic systems without a spot-film device, the requirements of paragraph 1 apply.(4) Other requirements for fluoroscopic beam limitation: (a) Means shall be provided to permit further limitation of the field. Beam-limiting devices manufactured after May 22, 1979, and incorporated in equipment with a variable source-image receptor distance and/or a visible area of greater than three hundred square centimeters shall be provided with means for stepless adjustment of the x-ray field.(b) All equipment with a fixed source-image receptor distance and a visible area of three hundred square centimeters 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 or less. Stepless adjustment shall, at the greatest source-image receptor distance, provide continuous field sizes from the maximum obtainable to a field size of five centimeters by five centimeters or less.(c) 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.(d) Compliance shall be determined with the beam axis indicated to be perpendicular to the plane of the image receptor. For noncircular x-ray fields used with circular image receptors, 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.(5) Spot-film devices shall meet the following additional requirements: (a) 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.(b) Neither the length nor the width of the x-ray field in the plane of the image receptor shall differ from the corresponding dimensions of the selected portion of the image receptor by more than three percent of the source-image receptor distance when adjusted for full coverage of the selected portion of the image receptor. The sum, without regard to sign, of the length and width differences shall not exceed four percent of the source-image receptor distance.(c) 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 source-image receptor distance shall be equal to, or less than, five centimeters by five centimeters.(d) 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 of the source-image receptor distance.(e) 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.(6) If a means exists to override any of the automatic x-ray field size adjustments required in subdivision b of subsection 1 that means: (a) Must be designed for use only in the event of system failure.(b) Must incorporate a signal visible at the fluoroscopist's position which will indicate whenever the automatic field size adjustment is overridden.(c) Must be clearly and durably labeled as follows: FOR X-RAY FIELD
LIMITATION SYSTEM FAILURE
2.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 or exposures at any time, but means may be provided to permit completion of any single exposure of the series in process.3.Radiation exposure rate limits.a. Entrance exposure rate allowable limits. (1) Fluoroscopic equipment which is provided with automatic exposure rate control: (a) The radiation exposure measured at the point where the center of the useful beam enters the patient shall not exceed two and fifty-eight hundredths millicoulomb per kilogram [10 roentgens] per minute, except during recording of fluoroscopic images or when provided with optional high-level control.(b) When provided with optional high-level control, the equipment shall not be operable at any combination of tube potential and current which will result in a radiation exposure rate in excess of one and twenty-nine hundredths millicoulomb per kilogram [5 roentgens] per minute at the point where the center of the useful beam enters the patient unless the high-level control is activated. [1] When the high-level control is activated, the equipment shall not be operable at any combination of tube potential and current that will result in an exposure rate in excess of five and sixteen hundredths millicoulomb per kilogram [20 roentgens] per minute at the point where the center of the useful beam enters the patient.[2] Special means of activation of high-level controls shall be required. The high-level control only shall be operable when continuous manual activation is provided by the operator.[3] A continuous signal audible to the fluoroscopist shall indicate that the high-level control is being employed.(2) Fluoroscopic equipment which is not provided with automatic exposure rate control: (a) The radiation exposure measured at the point where the center of the useful beam enters the patient shall not exceed one and twenty-nine hundredths millicoulomb per kilogram [5 roentgens] per minute, except during recording of fluoroscopic images or when provided with an optional high-level control and the high-level control is activated. [1] When the high-level control is activated, the equipment shall not be operable at any combination of tube potential and current that will result in an exposure rate in excess of five and sixteen hundredths millicoulomb per kilogram [20 roentgens] per minute at the point where the center of the useful beam enters the patient.[2] 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.[3] A continuous signal audible to the fluoroscopist shall indicate that the high-level control is being employed.(3) Compliance with the requirements of subsection 3 of this section shall be determined as follows:(a) Movable grids and compression devices shall be removed from the useful beam during the measurement.(b) If the source is below the table, the radiation exposure rate shall be measured one centimeter above the tabletop or cradle.(c) If the source is above the table, the radiation exposure rate shall be measured at thirty centimeters above the tabletop with the end of the beam-limiting device or spacer positioned as closely as possible to the point of measurement.(d) In a C arm type of fluoroscope, both stationary and mobile units shall meet the entrance exposure rate limits specified in paragraphs 1, 2, and 3 of subdivision a of subsection 3, shall be measured thirty centimeters from the input surface of the fluoroscopic imaging assembly with the source positioned at any available source-image receptor distance provided that the end of the spacer assembly or beam-limiting device is not closer than thirty centimeters from the input surface of the fluoroscopic imaging assembly.(e) In a lateral type of fluoroscope, the exposure rate shall be measured at a point fifteen centimeters 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 to the centerline of the x-ray table.(4) Periodic measurement of entrance exposure rate shall be performed by a qualified expert for both typical and maximum values as follows: (a) Such measurements shall be made annually or after any maintenance of the system which might affect the radiation exposure rate.(b) Results of these measurements shall be posted where any fluoroscopist may have ready access to such results while using the fluoroscope and in the record required in paragraph 5 of subdivision b of subsection 1 of section 33.1-10-06-03. Results of the measurements shall include the roentgen per minute, as well as the technique factors used to determine such results. The name of the person performing the measurements and the date the measurements were performed shall be included in the results.(c) Conditions of periodic measurements of typical entrance exposure rate are as follows: [1] The measurement shall be made under the conditions that satisfy the requirements of paragraph 4.[2] The kilovolts peak, mA, and other selectable parameters shall be the settings typical of clinical use on a twenty-three centimeters thick abdominal patient.[3] The x-ray systems that incorporate automatic exposure control shall have sufficient material placed in the useful beam to produce a milliamperage or kilovoltage, or both, to satisfy the conditions of item 2.[4] X-ray systems that do not incorporate an automatic exposure control shall utilize a milliamperage typical of clinical use of the x-ray system. Materials should be placed in the useful beam when conducting these periodic measurements to protect the imaging system.(d) Conditions of periodic measurements of maximum entrance exposure rate are as follows: [1] The measurement shall be made under the conditions that satisfy the requirements of paragraph 3.[2] The kVp, mA, and other selectable parameters shall be the maximum selectable parameters of clinical use of the x-ray system.[3] The x-ray systems that incorporate automatic exposure control shall have sufficient material placed in the useful beam to produce a kVp, mA, and other selectable parameters to satisfy the conditions of item 2.[4] X-ray systems that do not incorporate an automatic exposure control shall utilize the maximum kVp, mA, and other selectable parameters of clinical use of the x-ray system. Materials should be placed in the useful beam when conducting these periodic measurements to protect the imaging system.4.Barrier transmitted radiation rate limits.a. The radiation 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 five hundred sixteen thousandths microcoulomb per kilogram [2 milliroentgens] per hour at ten centimeters from any accessible surface of the fluoroscopic imaging assembly beyond the plane of the image receptor for each roentgen (C/kg) per minute of entrance exposure rate.b. Measuring compliance of barrier transmission. (1) The radiation 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 with no linear dimension greater than twenty centimeters.(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 above the tabletop.(3) If the source is above the tabletop and the source-image receptor distance 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.(4) Movable grids and compression devices shall be removed from the useful beam during the measurement.5.Indication of potential and current. During fluoroscopy and cinefluorography, the kilovolt and the milliampere shall be continuously indicated.6.Indication of air kerma rate and cumulative air kerma. Machines manufactured on or after June 10, 2006, shall provide displays of values of air kerma rate and cumulative air kerma and shall be viewable from the x-ray operator position. a. When the x-ray tube is activated and the number of images produced per unit time is greater than six images per second, the air kerma rate in mGy/minute shall be continuously displayed and updated at least once every second.b. The cumulative air kerma in units of mGy shall be displayed either within five seconds of termination of an exposure or displayed continuously and updated at least once every five seconds.c. The display of the air kerma rate shall be clearly distinguishable from the display of the cumulative air kerma.d. The air kerma rate and cumulative air kerma shall represent the value of conditions of free-in-air irradiation at one of the following reference locations specified according to the type of fluoroscope. (1) For fluoroscopies with x-ray source below the x-ray table, x-ray source above the table, or of lateral type, the reference locations shall be the respective locations specified in subparagraphs b, c, and e of paragraph 3 of subdivision a of subsection 3 for measuring compliance with air kerma rate limits.(2) For C-arm fluoroscopies, the reference location shall be fifteen centimeters from the isocenter toward the x-ray source along the beam axis. Alternatively, the reference location shall be at a point specified by the manufacturer to represent the location of the intersection of the x-ray beam with the patient's skin.e. Means shall be provided to reset to zero the display of cumulative air kerma prior to the commencement of a new examination or procedure.f. The displayed air kerma rate and cumulative air kerma shall not deviate from the actual values by more than plus or minus thirty-five percent over the range of six mGy/minute (0.6 R/min) and one hundred mGy (10 R) to the maximum indication of air kerma rate and cumulative air kerma, respectively. Compliance shall be determined with an irradiation time greater than three seconds.7.Source skin distance. The source to skin distance shall not be less than: a. Thirty eight centimeters on stationary fluoroscopes installed after August 1, 1974.b. Thirty-five and one-half centimeters on stationary fluoroscopes which were in operation prior to August 1, 1974.c. Thirty centimeters on all mobile fluoroscopes.d. Twenty centimeters for all mobile fluoroscopes used for specific surgical applications.8.Fluoroscopic timer.a. Means shall be provided to preset the cumulative on-time of the fluoroscopic tube. The maximum cumulative time of the timing device shall not exceed five minutes without resetting.b. 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.9.Control of scattered radiation.a. 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 twenty-five one hundredths millimeter lead equivalent.b. 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: (1) Is at least one hundred twenty centimeters from the center of the useful beam; or(2) The radiation has passed through not less than twenty-five one hundredths millimeter lead equivalent material, including drapes, bucky-slot cover-sliding or folding panel, or self supporting curtains, in addition to any lead equivalency provided by the protective apron referred to in paragraph 5 of subdivision a of subsection 1 of section 33.1-10-06-03.c. The department may grant exceptions to subdivision b of this subsection in some special procedures where a sterile field will not permit the use of the normal protective barriers. Where the use of prefitted sterilized covers for the barriers is practical, the department shall not permit such exception.10.Spot-film exposure reproducibility. Fluoroscopic systems equipped with spot-film mode shall meet the exposure reproducibility requirements of subsection 5 of section 33.1-10-06-06 when operating in the spot-film mode.11.Radiation therapy simulation system. Radiation therapy simulation systems shall be exempt from all the requirements of subsections 1, 3, 4, and 8 provided that: a. 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; andb. Such systems as do not meet the requirements of subsection 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.12.Structural shielding requirements (see appendix E).N.D. Admin Code 33.1-10-06-05
Adopted by Administrative Rules Supplement 370, October 2018, effective 1/1/2019.General Authority: NDCC 23.1-03-04; S.L. 2017, ch. 199, § 1
Law Implemented: NDCC 23.1-03-03, 23.1-03-04; S.L. 2017, ch. 199, § 18