New Jersey Administrative Code › Title 7 - ENVIRONMENTAL PROTECTION › Chapter 28 - RADIATION PROTECTION PROGRAMS › Subchapter 15 - MEDICAL DIAGNOSTIC X-RAY INSTALLATIONS › Section 7:28-15.2 - Definitions

Current through Register Vol. 56, No. 14, July 15, 2024
The words and terms listed below, when used in this subchapter, shall have the following meanings, unless the context indicates otherwise.
"Accessible surface" means the external surface of the enclosure or housing provided by the manufacturer.
"Acquired date" means the date the unit has been installed and is capable of use on patients.
"Aluminum equivalent" means the thickness of aluminum (type 1100 alloy) affording the same attenuation, under specified conditions, as the material in question.
"Anti-collision device" means either an electronic position sensor combined with a microprocessor or a mechanical touch bar microswitch which will stop all equipment movement and radiation exposures to prevent collision of any part of the radiation therapy simulator system with the patient, or damage to other components of the simulator system.
"Assembler" means any person engaged in the business of assembling, replacing, or installing one or more components into a diagnostic 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.
"Automatic exposure control" means a device which automatically controls one or more technique factors in order to obtain a required quantity of radiation at a preselected location(s) (for example, phototimer).
"Beam axis" means a line from the source through the center of the x-ray field.
"Beam-limiting device" means a mechanism which provides a means to restrict the dimensions of the x-ray field.
"C-arm x-ray system" means 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.
"Cassette holder" means a device, other than a spot-film device, that supports and/or fixes the position of an image receptor during an x-ray exposure.
"Certified components" means components of x-ray systems which are subject to the regulations promulgated under Public Law 90-602, the Radiation Control for Health and Safety Act of 1968, 21 Code of Federal Regulations, Chapter 1, Subchapter J, Radiological Health ( 21 C.F.R. Part 1020 et seq., Performance Standards for Ionizing Radiation Emitting Products).
"Certified system" means any x-ray system which has all certified components. Also known as a certified unit or a certified diagnostic x-ray system.
"Coefficient of variation" means the ratio of the standard deviation to the mean value of a population of observations. It is estimated using the following equation:
Data in image
"Computed tomography" (CT) means the production of a tomogram by the acquisition and computer processing of x-ray transmission data.
"Computed tomography dose index" (CTDI) means the integral of the dose measured along a line perpendicular to and centered at the tomographic plane divided by the product of the nominal tomographic section thickness and the number of tomograms produced in a single scan, that is:
Data in image
This definition assumes that the dose profile is centered around z=0 and that, for a multiple tomogram system, the scan increment between adjacent scans is nT.
"Contrast scale" (CS) for computed tomography means the change in the linear attenuation coefficient per CT number relative to water, that is:
Data in image
"Contrast ratio" for a light field is the ratio of the illumination three millimeters from the edge of the field towards the center of the field to the illumination three millimeters from the edge of the field away from the center of the field.
"Control panel" means the part of the x-ray control upon which are mounted the switches, knobs, push-buttons, and other hardware necessary for manually setting the technique factors.
"CT conditions of operation" means all selectable parameters governing the operation of a CT x-ray system, including nominal tomographic section thickness, filtration, and the technique factors.
"CT number" means the number used to represent the x-ray attenuation associated with each elemental area of the CT image.
"Dedicated mammography unit" means an x-ray system specifically designed for mammographic procedures.
"Diagnostic source assembly" means the tube housing assembly with a beam-limiting device attached.
"Diagnostic type protective tube housing" means an x-ray tube housing so constructed that the leakage radiation at a distance of one meter from the target cannot exceed 100 milliroentgens in one hour when the tube is operated at its maximum continuous rated current for the maximum continuous rated tube potential.
"Diagnostic x-ray system" means an x-ray system designed for irradiation of any part of the human body for the purpose of diagnostic imaging or measurement.
"Emergency off switch" means a switch located near the table or near the console which, when operated, turns off all power to the system.
"Entrance exposure rate" means the exposure per unit time at the point where the center of the useful beam enters the patient.
"Equipment" means x-ray equipment.
"Exposure" means a measure of the quantity of x or gamma radiation based upon its ability to ionize air through which it passes.
"Field emission equipment" means equipment which uses an x-ray tube in which electron emission from the cathode is due solely to the action of an electric field.
"Fluoroscopic imaging assembly" means a subsystem in which x-ray photons produce a fluoroscopic image. The subsystem includes the image intensifier, spot-film device, electrical interlocks, if any, and structural material providing linkage between the image receptor and diagnostic source assembly.
"General purpose radiographic x-ray system" means any radiographic x-ray system which is not limited by its design to the radiographic examination of a specific anatomical region.
"Half-value layer" (HVL) means the thickness of specified material which attenuates the x-ray beam so that the exposure is reduced to one-half of its original value.
"Image intensifier" means a device, installed in its housing, which instantaneously converts an x-ray pattern into a corresponding light image.
"Image receptor" means 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. In those cases where means are provided to preselect a portion of the image receptor, the term "image receptor" shall mean the preselected portion of the device.
"Image receptor support" means that part of the system designed to support the image receptor during a radiographic examination.
"kV" means kilovolts.
"kVp" (see "peak tube potential").
"Leakage radiation" means radiation emanating from the diagnostic source assembly except for the useful beam and radiation produced when the exposure switch or timer is not activated.
"Leakage technique factors" means the technique factors associated with the diagnostic source assembly which are used in measuring leakage radiation. They are defined as follows:
1. For diagnostic source assemblies intended for capacitor energy storage equipment, 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 10 millicoulombs that is 10 milliampere seconds (mAs) or the minimum obtainable from the unit, whichever is larger.
2. For diagnostic source assemblies intended for field emission equipment rated for pulsed operations, 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.
3. 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.
"Light field" means the area of the intersection of the light beam from the beam-lighting device and one of the set of planes parallel to the plane of the image receptor as well as at the plane of the image receptor, whose perimeter is the locus of points at which the illumination is one-fourth of the maximum in the intersection.
"mA" means milliampere.
"mAs" means milliampere second.
"Mobile x-ray equipment" means completely assembled x-ray equipment, which is mounted on a permanent base with wheels and/or casters and is used in multiple locations.
"Motor vehicle mounted" means an x-ray system permanently mounted and operated in a motor vehicle.
"Multiple-tube installation" means a radiographic installation in which one control panel may energize more than one radiographic x-ray tube.
"Noise" for computed tomography means the standard deviation of the fluctuations in CT number expressed as a percent of the attenuation coefficient of water. Its estimate (S[n]) is calculated using the following expression:
Data in image
"Nominal tomographic section thickness" means the full width at half-maximum of the sensitivity profile taken at the center of the cross-sectional volume over which x-ray transmission data are collected.
"Peak tube potential" means the maximum value of the potential difference across the x-ray tube during an exposure.
"Phantom" means a volume of material behaving in a manner similar to tissue with respect to the attenuation and scattering of radiation.
"Positive beam-limiting device" (PBL) means a device which automatically restricts the x-ray field to the size of the image receptor.
"Portable x-ray equipment" means x-ray equipment designed to be hand-carried.
"Primary protective barrier" see "protective barrier".
"Protective barrier" means a barrier of radiation-absorbing material used to reduce radiation exposure. The types of protective barriers are as follows:
1. "Primary protective barrier" means the material, excluding filters, intercepting the useful beam for protection purposes to reduce the radiation exposure so that it does not exceed two millirems in any one hour; and
2. "Secondary protective barrier" means a barrier sufficient to attenuate the stray radiation to reduce radiation exposure so that it does not exceed two millirems in any one hour.
"Qualified individual for the performance of radiation surveys for diagnostic x-ray equipment and therapy simulator systems" as required in this subchapter means an individual who meets at least one of the following criteria:
1. Certification by one of the following agencies in the specialty listed:
i. The American Board of Radiology in Diagnostic Radiological Physics or Radiological Physics;
ii. The American Board of Health Physics in Comprehensive Health Physics;
iii. The American Board of Medical Physics in Diagnostic Imaging Physics or Medical Health Physics;
iv. Certification issued by the Fellowship in the Canadian College of Physicists in Medicine which is equivalent to 1i or iii above; or
v. Certification by other national certifying boards which may be recognized by the Commission on Radiation Protection (Commission) where the person seeking recognition as a qualified individual for the performance of radiation surveys for diagnostic x-ray equipment and therapy simulator systems has petitioned the Commission in writing and where the Commission has issued a written determination that the certification in question meets the criteria of a qualified individual pursuant to this definition;
2. A bachelor's degree from an accredited college in biology, chemistry, radiation sciences, physics, engineering, or mathematics and at least five years of professional technical experience in the field of radiological physics or in the use of medical ionizing-radiation-producing equipment;
3. A master's or doctorate degree from an accredited college in radiological health, radiation sciences, physics, chemistry, environmental sciences, engineering or a related field and at least two years of professional technical experience in the field of radiological physics or in the use of medical ionizing-radiation-producing equipment;
4. Ten years of professional technical experience in the field of radiological physics or in a radiation protection activity. At least five years of the required health physics experience shall have been with medical ionizing-radiation-producing equipment; or
5. Any individual who does not meet at least one of the foregoing criteria may petition the Commission for recognition as a "qualified individual for the performance of radiation surveys for diagnostic x-ray equipment and therapy simulator systems". The individual shall submit a written petition to the Commission which contains sufficient information on his or her educational, professional, clinical, technical, employment and/or any other relevant experience. The Commission may approve any such petition based on its determination that the individual demonstrates competence to act as a qualified individual for the performance of radiation surveys for diagnostic x-ray equipment and therapy simulator systems.
"Qualified medical physicist for the supervision of quality assurance programs for diagnostic x-ray equipment" as required in this subchapter means an individual who meets at least one of the following criteria:
1. Certification by one of the following agencies in the specialty listed:
i. The American Board of Radiology in Diagnostic Radiological Physics or Radiological Physics;
ii. The American Board of Medical Physics in Diagnostic Imaging Physics;
iii. Certification issued by the Fellowship in the Canadian College of Physicists in Medicine which is equivalent to 1i or ii above; or
iv. Certification by other national certifying boards which may be recognized by the Commission where the person seeking recognition as a qualified medical physicist for the supervision of quality assurance programs for diagnostic x-ray equipment has petitioned the Commission in writing and where the Commission has issued a written determination that the certification in question meets the criteria of a qualified medical physicist pursuant to this definition;
2. A master's or doctorate degree from an accredited college in radiological health, radiation sciences, physics, chemistry, environmental sciences, engineering or a related field and at least three years of professional, clinical and technical experience in the field of radiological physics obtained under the supervision of a qualified medical physicist for the supervision of quality assurance programs for diagnostic x-ray equipment; or
3. Any individual who does not meet at least one of the foregoing criteria may petition the Commission for recognition as a qualified medical physicist for the supervision of quality assurance programs for diagnostic x-ray equipment. The individual shall submit a written petition to the Commission which contains sufficient information on his or her educational, professional, clinical, technical, employment and/or any other relevant experience. The Commission may approve any such petition based on its determination that the individual demonstrates competence to act as a qualified medical physicist for the supervision of quality assurance programs for diagnostic x-ray equipment.
"Qualified medical physicist for the supervision of quality assurance programs for therapy simulator systems" means an individual who meets at least one of the criteria listed below:
1. Is certified by the American Board of Radiology in therapeutic radiological physics or by the American Board of Medical Physics with special competency in radiation oncology physics;
2. Is certified by the American Board of Radiology in Radiological Physics which includes all three subspecialties of diagnostic radiological physics, therapeutic radiological physics, and medical nuclear physics.
3. Is certified by the American Board of Radiology or the American Board of Medical Physics in a specialty other than therapeutic radiological physics or radiation oncology physics and has at least three years of professional, clinical and technical experience obtained under the supervision of a qualified medical physicist for the supervision of quality assurance programs for therapy simulator systems;
4. Certification issued by the Fellowship in the Canadian College of Physicists in Medicine which is equivalent to 1, 2, or 3 above;
5. Certification by other national certifying boards which may be recognized by the Commission where the person seeking recognition as a qualified medical physicist for the supervision of quality assurance programs for therapy simulator systems has petitioned the Commission in writing and where the Commission has issued a written determination that the certification in question meets the criteria of a qualified medical physicist pursuant to this definition;
6. A master's or doctorate degree from an accredited college in radiological health, radiation sciences, physics, chemistry, environmental sciences, engineering or a related field and at least three years of professional, clinical and technical experience in the field of radiological physics obtained under the supervision of a qualified medical physicist for the supervision of quality assurance programs for therapy simulator systems; or
7. Any individual who does not meet at least one of the foregoing criteria may petition the Commission for recognition as a qualified medical physicist for the supervision of quality assurance programs for therapy simulator systems. The individual shall submit a written petition to the Commission which contains sufficient information on his or her educational, professional, clinical, technical, employment and/or any other relevant experience. The Commission may approve any such petition based on its determination that the individual demonstrates competence to act as a qualified medical physicist for the supervision of quality assurance programs for therapy simulator systems.
"Quality assurance" means an organized effort by the registrant to maintain a level of equipment performance to assure consistent production of diagnostic images without unnecessary radiation exposure. It includes quality control procedures and administrative procedures.
"Quality control" is the routine measurement of image quality and the performance of the diagnostic x-ray imaging system, from x-ray beam output to the viewing of radiographs, and the continual adjustment of that performance to an optimal and consistent level.
"Radiation therapy simulation system" means a radiographic, fluoroscopic or computed tomographic 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.
"Radiograph" means an image receptor on which the image is created directly or indirectly by an x-ray pattern and results in a permanent record.
"Radiographic imaging system" means any system whereby a permanent or temporary image is recorded on an image receptor by the action of ionizing radiation.
"Reference plane" for computed tomography means a plane which is displaced from and parallel to the tomographic plane.
"Registrant" means a person who is required to register a source of radiation with the Department pursuant to this chapter.
"Scan" for computed tomography means the complete process of collecting x-ray transmission data for the production of a tomogram. Data can be collected simultaneously during a single scan for the production of one or more tomograms.
"Scan increment" for computed tomography means the amount of relative displacement of the patient with respect to the CT x-ray system between successive scans measured along the direction of such displacement.
"Scan time" means the period of time between the beginning and end of photon transmission data accumulation for a single scan.
"Scan sequence" for computed tomography means a preselected set of two or more scans performed consecutively under preselected CT conditions of operation.
"Scattered radiation" means radiation that, during passage through matter, has changed in direction or in energy.
"Sensitivity profile" means the relative response of the CT x-ray system as a function of position along a line perpendicular to the tomographic plane.
"Single-purpose x-ray system" means an x-ray system which is limited by its design to the radiological examination of a specific anatomical region.
"Source" means the focal spot of the x-ray tube.
"Source-to-image receptor distance" (SID) means the distance from the source to the center of the input surface of the image receptor.
"Source-to-skin distance" (SSD) means the distance from the source of radiation to the patient's skin.
"Spot-film device" means a device intended to transport and/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.
"Stationary equipment" means equipment which is installed in a fixed location.
"Technique factors" means the conditions of operation of a diagnostic x-ray system. They are specified as follows:
1. For capacitor energy storage equipment, peak tube potential in kV and quantity of charge in mAs.
2. For field emission equipment rated for pulsed operation, peak tube potential in kV and number of x-ray pulses.
3. For computed tomography 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.
4. For computed tomography 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 in seconds when the scan time in seconds and the exposure time are equivalent.
5. 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.
"Tomogram" means an image of a planar section of a body part or object.
"Tomographic plane" for computed tomography means that geometric plane which is identified as corresponding to the tomographic image.
"Tomographic section" for computed tomography means the volume of an object whose x-ray attenuation properties are imaged in a tomogram.
"Tube housing assembly" means the x-ray tube housing with the x-ray tube insert installed. It includes high-voltage and/or filament transformers and other components that are contained within the tube housing.
"Tube rating chart" means the set of curves which specify the rated limits of operation of the tube in terms of the technique factors.
"Uncertified unit" means an x-ray system comprised of components that are not subject to the regulations promulgated under Public Law 90-602, the Radiation Control for Health and Safety Act of 1968, 21 Code of Federal Regulations, Chapter 1, Subchapter J, Radiological Health ( 21 C.F.R. Part 1020 et seq., Performance Standards for Ionizing Radiation Emitting Products). An "uncertified unit" is also known as a noncertified unit or a noncertified diagnostic x-ray system.
"Useful beam" means 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.
"Visible area" means that portion of the input surface of the image receptor over which incident x-ray photons are producing a visible image.
"Xeromammography" means the recording of an x-ray image of the breast using a uniformly charged photoconductive (selenium alloy) plate held in a light-proof cassette instead of using conventional x-ray film.
"X-ray control" means a device which controls input power to the x-ray high-voltage generator and/or the x-ray tube. It includes equipment such as timers, phototimers, automatic brightness control systems (stabilizers), and similar devices or means, which control the technique factors of an x-ray exposure.
"X-ray equipment" means an x-ray system, subsystem or component thereof.
"X-ray field" means that area of the intersection of the useful beam and any one of the set of planes parallel to 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.
"X-ray high-voltage generator" means a device which transforms electrical energy from the potential supplied by the x-ray control to the x-ray tube operating potential. The device may also include means for transforming alternating current to direct current, filament transformers for the x-ray tube(s), high-voltage switches, electrical protective devices, and other appropriate elements.
"X-ray system" means an assembly of components for the controlled production of x-rays. The system includes 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.
"X-ray subsystem" means any combination of two or more components of an x-ray system.
"X-ray tube" means any electron tube which is designed for the conversion of electrical energy into x-ray energy.