West Virginia Code of State Rules › Agency 64 - Health › Title 64 - LEGISLATIVE RULE WEST VIRGINIA DEPARTMENT OF HEALTH AND HUMAN RESOURCES › Series 64-23 - Radiological Health Rule › Section 64-23-7 - Requirements for Radiation Usage in the Healing Arts

Current through Register Vol. XLI, No. 28, July 12, 2024
7.1. Scope - This Section establishes
				requirements for which a registrant is responsible, for use of x-ray equipment
				by or under the supervision of an individual authorized by and registered in
				accordance with West Virginia statutes to engage in the healing arts or
				veterinary medicine. The provisions of this Section are in addition to, and not
				in substitution for, other applicable provisions of this rule.
7.2. Definitions - As used in this Section,
				the following definitions apply:
7.2.1.
				Accessible Surface - the external surface of the enclosure or housing of the
				radiation producing machine as provided by the manufacturer.
7.2.2. Added Filtration - any filtration
				which is in addition to the inherent filtration.
7.2.3. Aluminum Equivalent - the thickness of
				aluminum (type one thousand one hundred [1100] alloy) affording the same
				attenuation, under specified conditions, as the material in question. (The
				nominal chemical composition of type one thousand one hundred [1100] aluminum
				alloy is ninety-nine [99.00] percent minimum aluminum, twelve one-hundredths
				[0.12] percent copper.)
7.2.4.
				Assembler - any person engaged in the business of assembling, replacing, or
				installing one or more components into an x-ray system or subsystem. The term
				includes the owner of an x-ray system or his or her employee or agent who
				assembles components into an x-ray system that is subsequently used to provide
				professional or commercial services.
7.2.5. Attenuation Block - a block or stack,
				having dimensions twenty (20) centimeters by twenty (20) centimeters by three
				and eight-tenths (3.8) centimeters, of type 1100 aluminum alloy or other
				materials having equivalent attenuation.
7.2.6. Automatic Exposure Control (AEC) - a
				device which automatically controls one or more technique factors in order to
				obtain at a preselected locations a required quantity of radiation (Includes
				devices such as phototimers and ion chambers).
7.2.7. Barrier - the material, excluding
				filters, placed in the useful and scattered beam, for protection purposes, to
				reduce the radiation exposure.
7.2.8. Beam Axis - a line from the source
				through the centers of the x-ray fields.
7.2.9. Beam-limiting device - a device which
				provides a means to restrict the dimensions of the x-ray field.
7.2.10. C-arm X-ray System - an x-ray system
				in which the image receptor and x-ray tube housing assembly are connected by a
				common mechanical support system in order to maintain a desired spatial
				relationship. This system is designed to allow a change in the projection of
				the beam through the patient without a change in the position of the
				patient.
7.2.11. Cephalometric
				Device - a device intended for the radiographic visualization and measurement
				of the dimensions of the human head.
7.2.12. Certified Components - components of
				x-ray systems which are subject to regulations promulgated under Public Law
				90-602, the Radiation Control for Health and Safety Act of 1968, the Food and
				Drug Administration.
7.2.13.
				Certified System - any x-ray system which has one or more certified
				components.
7.2.14. Changeable
				Filters - any filter, exclusive of inherent filtration, which can be removed
				from the useful beam through any electronic, mechanical, or physical
				process.
7.2.15. Coefficient of
				Variation - the ratio of the standard deviation to the mean value of a set of
				observations. It is estimated using the following equation:
where:
{FUNC s} = Standard deviation of the observed values;
{OVERLINE FUNC ALIGNC x} = Mean value of observations in
				  sample;
{FUNC x SUB i} = ith observation in
				  sample;
{FUNC n} = Number of observations in sample.
7.2.16. Collimator - a device or
				mechanism by which the x-ray beam is restricted in size.
7.2.17. Computed Tomography (CT) - the
				production of a tomogram by the acquisition and computer processing of x-ray
				transmission data.
7.2.18. Control
				Panel - that part of the x-ray control upon which are mounted the switches,
				knobs, pushbuttons, and other hardware necessary for manually setting the
				technique factors.
7.2.19. Cooling
				Curve - the graphical relationship between heat units stored and cooling
				time.
7.2.20. Dead-man Switch - a
				switch so constructed that circuit-closing contact can be maintained only be
				continuous pressure on the switch by the operator.
7.2.21. Detector - a device which in the
				presence of radiation provides a signal or other indication suitable for use in
				measuring one or more quantities of incident radiation.
7.2.22. Diagnostic-type Protective Tube
				Housing - an x-ray tube housing so constructed that the leakage radiation at a
				distance of one (1) meter from the target cannot exceed one hundred (100)
				milliroentgens in one (1) hour when the tube is operated at its maximum
				continuous rated current for the maximum rated tube potential.
7.2.23. Diagnostic Source Assembly - the tube
				housing assembly with a beam-limiting device attached.
7.2.24. Diagnostic X-ray System - an x-ray
				system designed for irradiation of any part of the human or animal body for the
				purpose of diagnosis or visualization.
7.2.25. Diagnostic X-ray Imaging System - an
				assemblage of components for the generation, emission and reception of x-rays
				and the transformation, storage and visual display of the resultant x-ray
				image.
7.2.26. Diaphragm - a device
				or mechanism by which the x-ray beam is restricted in size.
7.2.27. Direct Scattered Radiation - that
				scattered radiation which has been deviated in direction only by materials
				irradiated by the useful beam (See "Scattered Radiation").
7.2.28. Entrance Exposure Rate - the exposure
				free in air per unit time at the point where the center of the useful beam
				enters the patient.
7.2.29. Field
				Emission Equipment - equipment which uses an x-ray tube in which electron
				emission from the cathode is due solely to the action of an electric
				field.
7.2.30. Filter - the
				material placed in the useful beam to absorb preferentially selected
				radiations.
7.2.31. Fluoroscopic
				Imaging Assembly - a subsystem in which x-ray photons produce a visible image.
				It includes the image receptor or receptors such as the image intensifier and
				spot-film device, electrical interlocks, if any, and structural material
				providing linkage between the image receptor and diagnostic source
				assembly.
7.2.32. Focal Spot
				(Actual) - the area projected on the anode on the x-ray tube bombarded by
				electrons accelerated from the cathode and from which the useful beam
				originates.
7.2.33. General Purpose
				Radiographic X-ray System - any radiographic x-ray system which, by design, is
				not limited to radiographic examination of specific anatomical
				regions.
7.2.34. Gonadal Shield - a
				protective barrier for the testes or ovaries.
7.2.35. Half-value Layer (HVL) - the
				thickness of specified material which attenuates the beam of radiation to an
				extent such that the exposure rate is reduced to one-half of its original
				value. In this definition, the contribution of all scattered radiation, other
				than any which might be present initially in the beam concerned, is deemed to
				be excluded.
7.2.36. Healing Arts
				Screening - the testing of human beings using x-ray machines for the detection
				or evaluation of health indications when such tests are not specifically and
				individually ordered by a licensed practitioner of the healing arts legally
				authorized to prescribe such x-ray tests for the purpose of diagnosis or
				treatment.
7.2.37. Heat Unit - a
				unit of energy equal to the product of the peak kilovoltage, milliamperes, and
				seconds, i.e., kVp x mA x second.
7.2.38. Image Intensifier - a device,
				installed in its housing, which instantaneously converts an x-ray pattern into
				a corresponding light image of higher intensity.
7.2.39. Image Receptor - any device, such as
				a fluorescent screen or radiographic film, which transforms incident x-ray
				photons either into a visible image or into another form which can be made into
				a visible image by further transformations.
7.2.40. Image Receptor Support - for
				mammographic systems, that part of the system designed to support the image
				receptor during mammography.
7.2.41. Inherent Filtration - the filtration
				of the useful beam provided by the permanently installed components of the tube
				housing assembly.
7.2.42. Interlock
				- a device for precluding access to an area of radiation hazard either by
				preventing entry or by automatically removing the hazard.
7.2.43. Irradiation - the exposure of matter
				to ionizing radiation.
7.2.44. kV -
				kilovolts.
7.2.45. kVp - the
				maximum value of the potential difference across the x-ray tube during an
				exposure.
7.2.46. kWs - kilowatt
				second.
7.2.47. Lead Equivalent -
				the thickness of lead affording the same attenuation, under specified
				conditions, as the material in question.
7.2.48. Leakage Technique Factors - the
				technique factors associated with the diagnostic source assembly which are used
				in measuring leakage radiation. They are defined as follows:
7.2.48.a. For diagnostic source assemblies
				intended for capacitor energy storage equipment, the maximum-rated peak tube
				potential and the maximum-rated number of exposures in an hour for operation at
				the maximum-rated peak tube potential with the quantity of charge per exposure
				being ten (10) millicoulombs, i.e., ten (10) milliampere seconds, or the
				minimum obtainable from the unit, whichever is larger;
7.2.48.b. For diagnostic source assemblies
				intended for field emission equipment rated for pulsed operation, the
				maximum-rated peak tube potential and the maximum-rated number of x-ray pulses
				in an hour for operation at the maximum-rated peak tube potential;
7.2.48.c. For all other diagnostic source
				assemblies, the maximum-rated peak tube potential and the maximum-rated
				continuous tube current for the maximum-rated peak tube potential.
7.2.49. Light Field - that area of
				the intersection of the light beam from the beam-limiting device and one (1) of
				the set of planes parallel to and including the plane of the image receptor,
				whose perimeter is the locus of points at which the illumination is one-fourth
				(1/4) of the maximum in the
				intersection.
7.2.50. Line-voltage
				Regulation - the difference between the no-load and the load line potentials
				expressed as a percent of the load line potential. It is calculated using the
				following equation:
Percent line-voltage regulation = 100
				  (Vn-Vl)/Vl
where:
Vn = No-load line potential;
				  and
Vl = Load line potential.
7.2.51. mA -
				milliampere.
7.2.52. mAs -
				milliampere second.
7.2.53. Maximum
				Line Current - the root-mean-square current in the supply line of an x-ray
				machine operating at its maximum rating.
7.2.54. Mobile X-ray Equipment - x-ray
				equipment mounted on a permanent base with wheels or casters for moving while
				completely assembled.
7.2.55.
				Patient - an individual or animal subjected to healing arts examination,
				diagnosis, or treatment.
7.2.56.
				PBL - See Positive Beam Limitation.
7.2.57. Peak Tube Potential - the maximum
				value of the potential difference across the x-ray tube during an
				exposure.
7.2.58. Phantom - a
				volume of material behaving in a manner similar to tissue with respect to the
				attenuation and scattering of radiation. This requires that both the atomic
				number (Z) and the density of the material be similar to that of
				tissue.
7.2.59. PID - a device on
				dental x-ray equipment used to indicate the beam position and to establish a
				definite source-surface (skin) distance. It may or may not incorporate or serve
				as a beam-limiting device.
7.2.60.
				Portable X-ray Equipment - x-ray equipment designed to be
				hand-carried.
7.2.61. Position
				Indicating Device - a device on dental x-ray equipment used to indicate the
				beam position and to establish a definite source-surface (skin) distance. It
				may or may not incorporate or serve as a beam-limiting device.
7.2.62. Positive Beam Limitation - the
				automatic or semi-automatic adjustment of an x-ray beam to the size of the
				selected image receptor, whereby exposures cannot be made without such
				adjustment.
7.2.63. Primary
				Protective Barrier - the material, excluding filters, placed in the useful
				beam, for protection purposes, to reduce the radiation exposure.
7.2.64. Protective Apron - an apron made of
				radiation absorbing materials used to reduce radiation exposure.
7.2.65. Protective Glove - a glove made of
				radiation absorbing materials used to reduce radiation exposure.
7.2.66. Qualified Expert - an individual who
				has demonstrated to the satisfaction of the agency that he possesses the
				knowledge and training to measure ionizing radiation, to evaluate safety
				techniques, and to advise regarding radiation protective needs.
7.2.67. Radiation Detector - a device which
				in the presence of radiation provides a signal or other indication suitable for
				use in measuring one or more quantities of incident radiation.
7.2.68. Radiation Therapy Simulation System -
				a radiographic or fluoroscopic x-ray system intended for localizing the volume
				to be exposed during radiation therapy and confirming the position and size of
				the therapeutic irradiation field.
7.2.69. Radiograph - an image receptor on
				which the image is created directly or indirectly by an x-ray pattern and
				results in a permanent record.
7.2.70. Radiographic Imaging System - any
				system whereby a permanent or semi-permanent image is recorded on an image
				receptor by the action of ionizing radiation.
7.2.71. Rating - the operating limits as
				specified by the component manufacturer.
7.2.72. Recording - producing a permanent
				form of an image resulting from x-ray photons.
7.2.73. Registrant as used in this Section -
				any person who owns or possesses and administratively controls and x-ray system
				which is used to deliberately expose humans or animals to the useful beam of
				the system and is required by the provisions of Sections 4. and 5. of this rule
				to register with this agency.
7.2.74. Scattered Radiation - radiation that,
				during passage through matter, has been deviated in direction.
7.2.75. Secondary Protective Barrier - a
				barrier sufficient to attenuate the stray radiation to the required
				degree.
7.2.76. Shutter - a device
				attached to the tube housing assembly which can intercept the entire cross
				Sectional area of the useful beam and which has a lead equivalency not less
				than that of the tube housing assembly.
7.2.77. Source-image Distance (SID) - the
				distance from the source to the center of the input surface of the image
				receptor.
7.2.78. Source - the
				focal spot of the x-ray tube.
7.2.79. Spot Film - a radiograph which is
				made during a fluoroscopic examination to permanently record conditions which
				exist during that fluoroscopic procedure.
7.2.80. Spot-film Device - a device intended
				to transport or position a radiographic image receptor between the x-ray source
				and fluoroscopic image receptor. It includes a device intended to hold a
				cassette over the input end of an image intensifier for the purpose of making a
				radiograph.
7.2.81. SSD - the
				distance between the source and the skin entrance plane of the
				patient.
7.2.82. Stationary X-ray
				Equipment - x-ray equipment which is installed in a fixed location.
7.2.83. Stray Radiation - the sum of leakage
				and scattered radiation.
7.2.84.
				Technique Factors - the following conditions of operation:
7.2.84.a. For capacitor energy storage
				equipment, peak tube potential in kV and quantity of charge in mAs;
7.2.84.b. For field emission equipment rated
				for pulsed operation, peak tube potential in kV, and number of x-ray
				pulses;
7.2.84.c. For CT x-ray
				systems designed for pulsed operation, peak tube potential in kV, scan time in
				seconds, and either tube current in mA, x-ray pulse width in seconds, and the
				number of x-ray pulses per scan, or the product of tube current, x-ray pulse
				width, and the number of x-ray pulses in mAs;
7.2.84.d. For CT x-ray systems not designed
				for pulsed operation, peak tube potential in kV, and either tube current in mA
				and scan time in seconds, or the product of tube current and exposure time in
				mAs and the scan time when the scan time and exposure time are equivalent;
				and
7.2.84.e. For all other
				equipment, peak tube potential in kV, and either tube current in mA and
				exposure time in seconds, or the product of tube current and exposure time in
				mAs.
7.2.85. Termination
				of Irradiation - the stopping of irradiation in a fashion which will not permit
				continuance of irradiation without the resetting of operating conditions at the
				control panel.
7.2.86.
				Therapeutic-type Tube Housing:
7.2.86.a. For
				x-ray therapy equipment not capable of operating at five hundred (500) kVp or
				above, the following definition applies: An x-ray tube housing so constructed
				that the leakage radiation averaged over any one hundred (100)
				cm2 area at a distance of one meter from the source
				does not exceed one (1) Roentgen in an hour when the tube is operated at its
				maximum rated continuous current for the maximum rated tube
				potential.
7.2.86.b. For x-ray
				therapy equipment capable of operating at five hundred (500) kVp or above, the
				following definition applies: An x-ray tube housing so constructed that the
				leakage radiation averaged over any one hundred (100)
				cm2 area at a distance of one meter from the source
				does not exceed one-tenth (0.1) percent of useful beam dose rate at one meter
				from the source for any of its operating conditions.
7.2.87. Tomogram - the depiction of the x-ray
				attenuation properties of a Section through the body.
7.2.88. Tube Housing Assembly - the tube
				housing with tube installed. It includes high-voltage or filament transformers
				and other appropriate elements when such are contained within the tube
				housing.
7.2.89. Tube Rating Chart
				- the set of curves which specify the rated limits of operation of the tube in
				terms of the technique factors.
7.2.90. Useful Beam - the radiation which
				passes through the tube housing port and the aperture of the beam-limiting
				device when the exposure switch or timer is activated.
7.2.91. Variable-aperture Beam-limiting
				Device - a beam-limiting device which has capacity for stepless adjustment of
				the x-ray field size at a given SID.
7.2.92. Visible Area - that portion of the
				input surface of the image receptor over which incident x-ray photons are
				producing a visible image.
7.2.93.
				X-ray Exposure Control - a device, switch, button or other similar means by
				which an operator initiates or terminates the radiation exposure. The x-ray
				exposure control may include such associated equipment as timers and back-up
				timers.
7.2.94. X-ray Equipment -
				an x-ray system, subsystem, or component thereof. Types of x-ray equipment are
				as follows:
7.2.94.a. Mobile X-ray Equipment -
				x-ray equipment mounted on a permanent base with wheels or casters for moving
				while completely assembled.
7.2.94.b. Portable X-ray Equipment - x-ray
				equipment designed to be hand-carried.
7.2.94.c. Stationary X-ray Equipment - x-ray
				equipment which is installed in a fixed location.
7.2.95. X-ray Field - that area of the
				intersection of the useful beam and any one of the set of planes parallel to
				and including the plane of the image receptor, whose perimeter is the locus of
				points at which the exposure rate is one-fourth of the maximum in the
				intersection.
7.2.96. X-ray
				High-voltage Generator - a device which transforms electrical energy from the
				potential supplied by the x-ray control to the tube operating potential. The
				device may also include means for transforming alternating current to direct
				current, filament transformers for the x-ray tubes, high-voltage switches,
				electrical protective devices, and other appropriate elements.
7.2.97. X-ray System - an assemblage of
				components for the controlled production of x-rays. It includes minimally an
				x-ray high-voltage generator, an x-ray control, a tube housing assembly, a
				beam-limiting device, and the necessary supporting structures. Additional
				components which function with the system are considered integral parts of the
				system.
7.2.98. X-ray Table - a
				patient support device with its patient support structure (tabletop) interposed
				between the patient and the image receptor during radiography or fluoroscopy.
				This includes, but is not limited to, any stretcher equipped with a radiolucent
				panel and any Table equipped with a cassette tray (or bucky), cassette tunnel,
				image intensifier, or spot-film device beneath the Tabletop.
7.2.99. X-ray Tube - any electron tube which
				is designed for the conversion of electrical energy into x-ray
				energy.