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TITLE 32: ENERGY CHAPTER II: DEPARTMENT OF NUCLEAR SAFETY SUBCHAPTER b: RADIATION PROTECTION

PART 360 USE OF X-RAYS IN THE HEALING ARTS INCLUDING MEDICAL, DENTAL, PODIATRY, AND VETERINARY MEDICINE

Section 360.10 Scope 360.20 Definitions 360.30 General Requirements and Administrative Controls 360.40 General Equipment and Operation Requirements for Diagnostic X-Ray Systems 360.50 Fluoroscopic Systems 360.60 Stationary Radiographic Systems Other Than Fluoroscopic, Dental Intraoral, Veterinary, or Systems Used Solely for Mammography 360.70 Mobile/Portable Radiographic Systems Other Than Systems Used Solely for Mammography 360.71 Requirements for Facilities Performing Mammography 360.80 Photofluorographic Systems 360.90 Intraoral Dental Radiographic Systems 360.100 Veterinary Radiographic Systems 360.110 Therapeutic X-Ray Installations 360.120 Special Requirements for X-Ray Therapy Equipment Operated at Potential of Fifty (50) kVp and Below 360.APPENDIX A Medical Radiographic Exposure Limits 360.APPENDIX B Mammography Dose Limit 360.ILLUSTRATION A Thimble and Pancake Chamber - Radiation Measuring Devices 360.ILLUSTRATION B Mammography Dose Evaluation Graph 360.TABLE A Filtration Required as a Function of Operating kVp (Repealed) 360.TABLE B Half-Value Layer as a Function of Tube Potential 360.TABLE C Entrance Exposure Limits Per Intraoral Bitewing Film

AUTHORITY: Implementing and authorized by the Radiation Protection Act of 1990 (P.A. 86-1341, effective September 7, 1990)

SOURCE: Filed April 20, 1974 by the Department of Public Health; old rules repealed, new rules adopted at 4 Ill. Reg. 25, p. 157, effective July 1, 1980; transferred to the Department of Nuclear Safety by P.A. 81-1516, effective December 3, 1980; codified at 7 Ill. Reg. 16406; amended at 10 Ill. Reg. 13271, effective July 28, 1986; amended at 13 Ill. Reg. 803, effective April 1, 1989; amended at 15 Ill. Reg. 6180, effective April 16, 1991.

Section 360.10 Scope

a) This Part establishes requirements for use of x-ray producing devices in the healing arts by a practitioner licensed to practice a treatment of human ailments by virtue of the Medical Practice Act of 1987 (Ill. Rev. Stat. 1987, ch. 111, pars. 4400-1 et seq.), the Illinois Dental Practice Act (Ill. Rev. Stat. 1987, ch. 111, pars. 2301 et seq.), or the Podiatric Medical Practice Act of 1987 (Ill. Rev. Stat. 1987, ch. 111, pars. 4801 et seq.), or by a medical radiographer or radiation therapy technologist accredited in accordance with the provision of 32 Ill. Adm. Code 401.100 or an individual exempt from the provisions of 32 Ill. Adm. Code 401, by Section 401.30 of that Part, acting under the supervision, prescription or direction of such licensed person or the non-human use of x-ray by veterinarians by virtue of the Veterinary Medicine and Surgery Practice Act of 1983 (Ill. Rev. Stat. 1987, ch. 111, pars. 7001 et seq.). The provisions of this Part are in addition to, and not in substitution for, other applicable provisions of 32 Ill. Adm. Code 310, 320, 340, 400, and 410.

b) It is recognized that some installations and equipment designed before the adoption of this Part, coupled with conditions of use, may be adequate to achieve minimum exposures. Request for exemption from some provisions of this Part will be considered in accordance with 32 Ill. Adm. Code 310.30(a).

(Source: Amended at 13 Ill. Reg. 803, effective April 1, 1989)

Section 360.20 Definitions

As used in this Part, the following definitions apply:

"Accelerator" means any therapeutic machine capable of producing a useful beam of x-rays or charged particles with energies greater than 500 keV.

"Added filtration" means the effect of the material (filter) added to the inherent filtration.

"Aluminum equivalent" means the thickness of type 1100 aluminum alloy affording the same attenuation, under specified conditions, as the material in question. The nominal chemical composition of type 1100 aluminum alloy is 99.00 percent minimum aluminum, 0.12 percent copper.

"Automatic exposure control" means a device which automatically controls 1 or more technique factors in order to obtain at a preselected location(s) a required quantity of radiation (see "Phototimer").

"Barrier" (see "Protective barrier").

"Beam axis" means a line from the source through the center of the x-ray field.

"Beam-limiting device" means a device which provides a means to restrict the dimensions of the x-ray field (see "Collimator", "Diaphragm", and "Shutter").

"Certified system" means an x-ray system which is subject to regulations promulgated under Public Law 90-602, the Radiation Control for Health and Safety Act of 1968 (42 U.S.C.A. 263(b) et seq.), 21 CFR 1000.3 et seq., in effect as of April 1, 1988, exclusive of subsequent amendments or editions. A copy of this document is available for public inspection at the Illinois Department of Nuclear Safety (Department), 1035 Outer Park Drive, Springfield, Illinois.

"Collimator" means a device or mechanism by which the x-ray beam is restricted in size (see "Beam-limiting device").

"Contact therapy system" means an x-ray system used for therapy with the x-ray tube port placed in contact with or within 5 centimeters of the surface being treated.

"Control panel" means that part or parts of the x-ray system upon which are mounted the switches, knobs, pushbuttons, and other hardware necessary for setting the technique factors prior to initiating an x-ray exposure.

"Dead-man switch" means a switch so constructed that a circuit- closing contact can be maintained only by continuous pressure on the switch by the operator.

"Diagnostic source assembly" means an x-ray tube housing assembly, designed for use in diagnostic x-ray applications, with a beam limiting device attached.

"Diagnostic-type protective tube housing" means an x-ray tube housing constructed so that when a beam limiting device is attached, the leakage radiation measured at a distance of 1 meter from the source cannot exceed 100 mR in 1 hour when the tube is operated at its maximum continuous rated current for the maximum rated tube potential.

"Diaphragm" means a device or mechanism by which the x-ray beam is restricted in size (see "Beam-limiting device").

"Filter" means material placed in the useful beam to absorb, preferentially, radiations based on energy level (see "Filtration" and "Inherent filtration").

"Filtration" means the act of preferentially absorbing radiation with filters or inherent filtration (see "Filter" and "Inherent filtration").

"General purpose radiographic x-ray system" means any radiographic x-ray system which, by design, is not limited to radiographic examination of specific anatomical regions.

"Gonad shield" means a protective device for the testes or ovaries which provides a minimum of 0.50 mm lead equivalent protection.

"Half-value layer (HVL)" means the thickness of a specified material that attenuates the beam of radiation to an extent such that the exposure rate is reduced to one-half of its original value.

AGENCY NOTE: The contribution of all scattered radiation, other than any that might be present initially in the beam concerned, is minimized.

"Healing arts screening" means the examination of human beings using x-ray machines for the detection or evaluation of potential diseases when such examinations are not specifically ordered by a licensed practitioner of the healing arts legally authorized to prescribe such x-ray examinations for the purpose of diagnosis or treatment. However, healing arts screening does not include mammography on self-referred patients.

"Image intensifier" means a device, installed in a housing, which 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.

"Inherent filtration" means the filtration permanently in the useful beam; it includes the effect of the x-ray tube window and any permanent tube or source enclosure (see "Filter" and Filtration").

"Interlock" means a device arranged or connected such that the occurrence of an event or condition is required before a second event or condition can occur or continue to occur.

"Kilovolts peak (kVp)" means the crest value, in kilovolts, of the electric potential applied to the x-ray tube between the cathode and anode of a pulsating electric potential generator.

"Lead equivalent" means the thickness of lead affording the same attenuation, under specified conditions, as the material in question.

"Leakage radiation" means all radiation emanating from the diagnostic source assembly except for:

The useful beam; and

The radiation produced when the exposure switch or timer is not activated.

"Leakage technique factors" means the technique factors used to measure leakage radiation from the diagnostic source assembly. They are defined as follows:

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 10 millicoulombs, i.e. 10 milliampere seconds, or the minimum obtainable from the unit, whichever is larger.

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.

For all other equipment, the maximum-rated peak tube potential and the maximum-rated continuous tube current for the maximum-rated peak tube potential.

"Light field" means that area of the intersection of the light beam from the beam-limiting device and any one of the sets of planes parallel to and including the plane of the image receptor. The edge of the light field is defined as the locus of points at which the illumination is 25 percent of that at the center of the light field.

"Mammography" means radiography of the breast for the purpose of enabling a physician to determine the presence, size, location and extent of cancerous or potentially cancerous tissue in the breast.

"Mammography dosimetry test phantom" means a phantom for determining the mean glandular breast dose. For automatic exposure control mammography systems it shall be any phantom material that is equivalent to a nominal 4.5 centimeter compressed breast of average density (i.e., 50 percent adipose and 50 percent glandular tissue).

"Mammography System" means an x-ray system that is used to perform mammography.

"Medical radiographer" means a person other than a licensed practitioner, accredited in accordance with the provisions of 32 Ill. Adm. Code 401, or an individual exempt from the provisions of 32 Ill. Adm. Code 401, who performs medical radiation procedures and applies x-radiation, to any part of the human body, for diagnostic purposes while under the supervision of a licensed practitioner.

"Mobile equipment" (see "X-ray equipment").

"Non-certified system" means an x-ray system which is not subject to regulations promulgated under Public Law 90-602, the Radiation Control for Health and Safety Act of 1968 (see "Certified system").

"Personnel monitoring" means the determination of radiation exposure to a person. Devices used for this purpose may include, but are not limited to, film badges, pocket dosimeters, and thermoluminescent dosimeters worn by the individual.

"Phototimer" means a method for controlling radiation exposures to image receptors by the amount of radiation which reaches a radia- ion monitoring device(s). The radiation monitoring device(s) is part of an electronic circuit which controls the duration of time the tube is activated (see "Automatic exposure control").

Portable equipment" (see "X-ray equipment").

"Position indicating device" means a device on intraoral dental x-ray equipment used to indicate the beam position and to establish a definite source-skin distance.

"Positive beam limitation" means a beam-limiting device which will, at the source-image receptor distance for which the device is designed, either cause automatic adjustment of the x-ray field in the plane of the image receptor to the image receptor size within 5 seconds after insertion of the image receptor or, if adjustment is accomplished automatically in a time interval greater than 5 seconds or is manual, prevent production of x-rays until such adjustment is completed. For SIDs at which the device is not intended to operate, the device prevents the production of x-rays.

"Primary protective barrier" (see "Protective barrier").

"Protective apron" means an apron of radiation absorbing materials, at least 0.25 mm lead equivalent, used to reduce exposure from stray radiation (see "Stray radiation").

"Protective barrier" means a barrier of radiation absorbing material(s) used to reduce radiation exposure. The types of protective barriers are as follows:

"Primary protective barrier" means the material, excluding filters, placed in the useful beam to reduce the radiation exposure.

"Secondary protective barrier" means a barrier sufficient to attenuate the stray radiation to the required degree (see "Stray radiation").

"Protective glove" means a glove made of radiation absorbing materials, at least 0.25 mm lead equivalent, used to reduce exposure from stray radiation (see "Stray radiation").

"Qualified expert" means an individual who has demonstrated to the satisfaction of the Department that he or she possesses the knowledge and training to measure ionizing radiation, to evaluate safety techniques, and to advise regarding radiation protection needs. Satisfactory demonstration of such knowledge and training should include certification by a nationally recognized credentialing entity in the field of radiation protection. "Radiation therapy simulation system" means a radiographic/ fluoroscopic x-ray system used exclusively for localizing the volume to be exposed during radiation therapy and confirming the position and size of the therapeutic irradiation field.

"Radiologist" means a physician or veterinarian who is either:

Certified by the American Board of Radiology in diagnostic radiology or general radiology;

Certified by the American Osteopathic Board of Radiology;

Certified by the American Chiropractic Board of Radiology; or

Certified by the American College of Veterinary Radiology; or

Eligible for certification by any College or Board identified above.

"Scatter radiation" means radiation that, during passage through matter, has been deviated in direction.

"Secondary protective barrier" (see "Protective barrier").

"Shutter" means an adjustable beam-limiting or attenuating device, usually made of lead, fixed to an x-ray tube housing to intercept or collimate the useful beam (see "Beam-limiting device").

"SID" means source-image receptor distance (see "Source-image receptor distance").

"Source" means the focal spot of the x-ray tube.

"Source-image receptor distance" means the distance from the source to the center of the input surface of the image receptor.

"Source-skin distance (SSD)" means the distance measured along the central ray from the center of the front surface of the x-ray focal spot to the surface of the irradiated object.

"Special purpose x-ray system" means any radiographic x-ray system which, by design, is limited to radiographic examination of a specific anatomical region.

"Spot film" means a radiograph which is made during a fluoroscopic examination to permanently record conditions which exist during that fluoroscopic procedure.

"Stationary equipment" (see "X-ray equipment").

"Stray radiation" means the sum of leakage and scatter radiation.

"Technique factors" means the electrical potential (kilovolts), current (milliamperes), exposure time parameters (seconds or pulses) or a combination thereof, selectable at the control panel of an x-ray system (see "Control panel").

"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.

"X-ray equipment" means an x-ray system, sub-system, or component thereof. Types of x-ray equipment are as follows:

"Mobile x-ray equipment" means x-ray equipment mounted on a permanent base with wheels and/or casters for moving while completely assembled.

"Portable x-ray equipment" means x-ray equipment designed to be hand-carried.

"Stationary x-ray equipment" means x-ray equipment which is installed in a fixed location.

"X-ray field" means, for diagnostic purposes, that area of the intersection of the useful beam and any 1 of the set of planes parallel to and including the plane of the image receptor. The edge of the x-ray field is defined as the locus of points at which the exposure is 25 percent of that at the center of the x-ray field.

"X-ray system" means an assemblage of components for the controlled production of x-rays. It includes minimally an x-ray high-voltage generator, an x-ray control panel, an x-ray 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.

(Source: Amended at 15 Ill. Reg. 6180, effective April 16, 1991)

Section 360.30 General Requirements and Administrative Controls

The requirements in this Section apply to all uses of x-rays in veterinary medicine and to all uses of x-rays in the Healing Arts including the use of x-rays for both diagnostic and therapeutic purposes. Additional requirements for all diagnostic x-ray systems are in Section 360.40 and specific equipment application classes are contained in Sections 360.50 through 360.100. For therapeutic x-ray systems also see Sections 360.110 and 360.120.

a) Registrant - The registrant shall:

1) Direct the operation of the x-ray system(s);

2) Register with the Department, in accordance with the provisions of 32 Ill. Adm. Code 320, all x-ray equipment which is used at the facility;

3) Register with the Department, in accordance with the provisions of 32 Ill. Adm. Code 320, all portable or mobile x-ray equipment used by the Registrant;

4) Submit an application for inspection of radiation machines to the Department in accordance with 32 Ill. Adm. Code 410 and, if the inspection is performed by a qualified nondepartment inspector, submit a copy of the radiation inspection report to the Department;

5) Permit operation of the x-ray system(s) only by individuals who are licensed in accordance with State law (See Section 360.10(a)), or who are accredited by the Department or are exempt from such requirements in accordance with the provisions of 32 Ill. Adm. Code 401;

6) Inform all individuals who work in activities pursuant to the operator's registration of their rights in accordance with the provisions of 32 Ill. Adm. Code 400; and

7) Maintain records showing the receipt, transfer, use, storage, and disposal of all sources of radiation in accordance with the provisions of 32 Ill. Adm. Code 310 and 320.

b) Shielding - Each installation shall be provided with such primary barriers and/or secondary barriers as are necessary to assure compliance with the provisions of 32 Ill. Adm. Code 340.1010, 340.1040 and 340.1050.

c) An x-ray system which does not meet the provisions of this Part shall not be operated for diagnostic or therapeutic purposes if so ordered by the Director.

d) If an x-ray system is identified as not being in compliance with the provisions of this Part and if that system is accessible for use, it shall be rendered inoperable (i.e. dismantle the x-ray source from the source support assembly) if so ordered by the Director.

e) Unauthorized Exposure - Individuals shall not be exposed to the useful beam except for healing arts purposes and only when such exposure has been authorized by a licensed practitioner of the healing arts. This provision specifically prohibits deliberate exposure for the following purposes:

1) Exposure of individuals for training, demonstration, or other non-healing arts purposes.

2) Exposure of individuals for the purpose of "healing arts screening" (see Section 360.20).

f) Personnel Monitoring and Reporting Requirements - All persons who are associated with the operation of an x-ray system are subject to the occupational exposure limits and the requirements for the determination of the doses which are contained in 32 Ill. Adm. Code 340.1010, 340.1020, 340.1040, 340.2010, and 340.2020 and the reporting requirements as stated in 32 Ill. Adm. Code 340.4010 through 340.4080.

g) The registrant shall comply with the requirements of the Department's rules entitled, Notices, Instructions and Reports to Workers; Inspections, 32 Ill. Adm. Code 400.

h) Maintenance Records and Associated Information - The registrant shall maintain, for a period of at least 3 inspection cycles (see 32 Ill. Adm. Code 410.60(d)), the following information for each x-ray system for inspection by the Department:

1) Separate records of maintenance and modifications performed on each x-ray system with the name(s) of the individual(s) who performed such services and the date(s) performed.

2) A copy of all correspondence with the Department regarding the registrant's x-ray program.

i) Staff Qualifications - The registrant shall maintain for review by the Department:

1) A current staffing plan indicating the names of all individuals responsible for operating x-ray equipment and the scope of their duties at the facility.

2) Current certificates of accreditation (clear, legible copies are acceptable), issued by the Department in accordance with the provisions of 32 Ill. Adm. Code 401, for all individuals who are required to be so accredited.

j) Radiation Safety Program - The registrant shall provide for annual in-service training in radiation safety for individuals (excluding licensed practitioners) that apply ionizing radiation at the facility, to ensure their awareness of the registrant's radiation safety practices and policies.

1) The in-service training must include the following topics:

A) Operating and emergency procedures for the radiation machine(s);

B) Use of personnel and patient protective devices;

C) Procedures to minimize patient and personnel exposure, as required by Section 360.40;

D) Use of personnel monitoring devices (if such devices are used at the facility);

E) Film processing procedures; and

F) Prohibited uses of fluoroscopic machines (if such machines are used at the facility), as described in Section 360.40(j).

2) The registrant shall maintain for a period of at least 3 inspection cycles (see 32 Ill. Adm. Code 410.60(d)), documentation, signed by persons who apply ionizing radiation, that indicates the date and content of training provided.

3) The registrant shall provide to each individual subject to in-service training a written policy statement outlining the registrant's radiation safety practices and policies specified in subsection (j)(1) above.

(Source: Amended at 15 Ill. Reg. 6180, effective April 16, 1991)

Section 360.40 General Equipment and Operation Requirements for Diagnostic X-ray Systems

The requirements of this Section apply to all diagnostic x-ray systems. Additional requirements for specific equipment application classes are in Sections 360.50 through 360.100.

a) Half-Value Layer - The half-value layer of the useful beam for a given x-ray tube potential shall not be less than the values shown in Table B of this Part. If it is necessary to determine a half- value layer at an x-ray tube potential which is not listed in Table B, linear interpolation or extrapolation may be utilized to determine the appropriate value.

b) Beam-On Indicators

1) The control panel shall include a device (usually a milliammeter or labeled indicator lamp) which will give positive indication of the production of x-rays whenever the x-ray tube is energized.

2) In addition, on certified systems, a signal audible to the operator shall indicate that the exposure has terminated.

c) Mechanical Support of Tube Head - The tube housing assembly supports shall be adjusted such that the tube housing assembly will remain stable during an exposure unless tube housing movement is a designed function of the x-ray system.

d) Diagnostic Source Assembly Leakage Radiation Limits - The leakage radiation measured at a distance of 1 meter from the source shall not exceed 100 milliroentgens in 1 hour when the tube is operated at its leakage technique factors.

e) Exposure Switch - The exposure switch shall be a dead-man switch.

f) Patient or Film Support - When a patient or film must be provided with auxiliary support during a radiation exposure:

1) No person shall be used routinely to hold film or patients; and

2) Unless the procedure precludes their use, mechanical holding devices shall be used to restrain patients. For example, mechanical holding devices could not be used if the devices would preclude clear visualization of the tissue being examined.

AGENCY NOTE: The radiation dose received by radiation workers, patients, and the general public can be reduced if mechanical patient and film support devices are used for radiographic and fluoroscopic procedures. In the event that an individual must be used in lieu of mechanical patient or film support devices to hold patients or films, every effort should be made to limit the individual's exposure to radiation. This can be accomplished by not assigning to a single individual the task of supporting patients and films during radiographic and fluoroscopic examinations. Rather, a number of individuals may be rotated through the assignment, thereby reducing the radiation exposure to one individual.

g) Personnel Protection -

1) Except for patients who cannot be moved out of the room, only the staff and ancillary personnel required for the medical procedure or training shall be in the room during the radiographic/fluoroscopic exposure.

2) Individuals who must be in the room with the patient being radiographed or fluoroscoped shall be positioned such that no part of the individual's body will be exposed to:

A) The useful beam unless protected by 0.5 millimeter lead equivalent apparel or device, and

B) Stray radiation unless protected by 0.25 millimeter lead equivalent apparel or device.

AGENCY NOTE: If apparel is used, it should cover as much of the individual's trunk and upper leg surface areas as possible. Apparel that protects both posterior and anterior surfaces is recommended. If a device, e.g., protective screen/barrier, is used in lieu of protective apparel, the device should be of such a width and height to afford protection as would be provided if apparel was worn.

h) Technique Guides - In the vicinity of each radiographic x-ray system's control panel, a technique guide shall be provided which specifies for routine examinations performed with that system, the following information:

AGENCY NOTE: This requirement is applicable to both dental intraoral and extraoral radiographic systems.

1) Patient's anatomical size versus technique factors to be utilized,

2) Type and size of the film or film-screen combination to be used, and

3) SID to be used.

4) For automatic exposure control (AEC) systems (i.e., systems employing photo-multiplier tubes or ionization chambers to terminate the x-ray exposure) with selectable exposure detectors and density settings, the technique guide shall also specify the appropriate exposure detector(s) and density setting to be utilized for each radiographic examination listed.

5) For AEC systems, the technique guide shall specify the requirements of subsections (h)(1) through (3) above to be followed if operated in a non-automatic mode.

i) Patient Exposure Criteria - Procedures and auxiliary equipment designed to minimize patient and personnel exposure commensurate with needed diagnostic information shall be used.

AGENCY NOTE: It is the intent of subsection (i) to provide for the optimum optical density on the film while minimizing patient exposure. The kVp and SSD employed in radiographic examinations should be as great as practical and consistent with the diagnostic objectives of the study. The x-ray equipment should permit use of the optimum kVp that will reduce the doses to the patient based on the required optical density of the film. The milliamperage should be high enough to permit as short an exposure time as is necessary to limit the effects of motion, which would result in the loss of the radiograph's usefulness. In addition, x-ray films, intensifying screens, and other image recording devices should be as sensitive as is consistent with the requirements of the examination. Non-screen films should not be used unless absolutely necessary for a specific examination.

j) Prohibited Use - Fluoroscopy shall not be used as a substitute for radiography or in lieu of proper anatomical positioning/centering procedures prior to radiographic studies (see 32 Ill. Adm. Code 310.100 for additional prohibited uses).

k) X-ray Film Processing Systems-

1) Manual film processing systems shall be monitored by the registrant to assure:

A) The use of a dedicated darkroom timer with an adjustable preset function. The timer shall be used to adjust film processing time according to solution temperature.

B) The use of a dedicated darkroom thermometer. The thermometer shall be used to adjust the film processing time according to solution temperature.

C) The use of a film processing guide. The guide shall contain, at a minimum, information regarding time(s) and temperature(s) (as recommended by the processing chemical manufacturer) used by the registrant to develop radiographs.

D) The frequency at which film processing chemicals are changed. At a minimum, the interval as recommended by the chemistry manufacturer shall be used.

E) The darkroom safe light illumination is adequate for the film speed(s) and the darkroom operating procedures used to prevent fogging of unprocessed film.

2) Automated film processing shall be monitored by the registrant to assure that:

A) The temperature of film processing chemicals is appropriate for the type of film(s) being processed at the film transport speed selected.

B) The film processing chemicals used and their replenishing rate (if applicable) are appropriate for the film transport speed selected.

C) The darkroom safe light illumination is adequate for the film speed(s) and the darkroom operating procedures used (to prevent fogging of unprocessed film).

l) Gonadal Shielding - Except for cases in which it would interfere with the diagnostic procedure, gonadal shielding of not less than 0.50 millimeters of lead equivalent shall be used for patients (who have not passed the reproductive age) during those radiographic procedures in which the gonads are in the useful beam.

AGENCY NOTE: Protection of the embryo or fetus from radiation exposure during radiological examination or treatment of a woman of childbearing age (potentially pregnant) should be given special consideration. However, in practice, medical needs should be the primary factors in deciding when to administer the examination.

(Source: Amended at 15 Ill. Reg. 6180, effective April 16, 1991)

Section 360.50 Fluoroscopic Systems

In addition to the provisions of Sections 360.10, 360.30 and 360.40, the requirements of this Section apply to x-ray equipment and associated facilities used for fluoroscopy.

a) Beam Limitation - The x-ray field shall, whenever possible, be limited by adjustable shutters. In addition:

1) For x-ray equipment with adjustable shutters, the mechanism(s) (manual/automatic mode selector(s)) provided for activating and positioning the shutters shall function properly. This requirement applies to shutters used in both fluoroscopic and spot filming procedures.

2) For fluoroscopic equipment without image intensifiers, the x-ray field shall not extend beyond the entire visible area of the image receptor. This requirement applies to field sizes for both fluoroscopic and spot filming procedures.

AGENCY NOTE: Visible area means that portion of the input surface of the image receptor over which incident x-ray photons are producing an image visible to the fluoroscopist.

3) For fluoroscopic equipment with image intensifiers, 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 3 percent of the SID. The sum of the excess length and the excess width shall be no greater than 4 percent of the SID. This requirement applies to field sizes for both fluoroscopic and spot filming procedures.

AGENCY NOTE: Visible area means that portion of the input surface of the image receptor over which incident x-ray photons are producing an image visible to the fluoroscopist.

b) Timer - A manual reset, cumulative timing device shall be used which will either indicate elapsed on-time by an audible signal or turn off the system when the total exposure time exceeds a predetermined limit not exceeding 5 minutes in 1 or a series of exposures.

c) Primary Barrier/Interlock - These devices shall function so that:

1) The entire cross section of the useful beam is intercepted by the primary protective barrier of the fluoroscopic image assembly at any SID; and

2) The fluoroscopic tube is interlocked to prevent the unit from producing x-rays unless the primary barrier is in position to intercept the useful beam, as specified in subsection (c)(1) above, at all times.

d) Source-Skin Distance - The SSD shall not be less than:

1) 38 centimeters (15 inches) on stationary fluoroscopes which are defined as certified systems,

2) 35.5 centimeters (14 inches) on stationary fluoroscopes which are defined as non-certified systems,

3) 30 centimeters (12 inches) on all mobile fluoroscopes,

4) 20 centimeters (8 inches) for image-intensified fluoroscopes used for a specific surgical application.

e) Entrance Exposure Rate (Non-Certified Systems) - Non-certified fluoroscopic systems shall not be operable at any combination of tube potential and current which will result in an exposure rate in excess of 10 Roentgens per minute at the point where the center of the useful beam enters the patient.

f) Entrance Exposure Rate (Certified Systems) -

1) Certified Systems With Automatic Exposure Rate Control - Fluoroscopic systems which are 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 10 Roentgens per minute at the point where the center of the useful beam enters the patient, except:

A) During recording of fluoroscopic images; or

B) When an optional high level control is provided. (See subsection (f)(3) below.)

2) Certified Systems Without Automatic Exposure Rate Control - Fluoroscopic systems which are 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 5 Roentgens per minute at the point where the center of the useful beam enters the patient, except:

A) During recording of fluoroscopic images; or

B) When an optional high level control is activated. (See subsection (f)(3) below.)

3) When provided with optional high level control, the equipment shall not be operable at any combination of the tube potential and current which will result in an exposure rate in excess of 5 Roentgens per minute at the point where the center of the useful beam enters the patient unless the high level control is activated.

A) Separate 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.

B) A continuous signal audible to the fluoroscopist shall indicate that the high level control is being employed.

4) Compliance with the requirements of subsections (e) and (f)(1), (2) and (3) above shall be determined as follows:

A) For systems employing automatic exposure rate control, material having an equivalency of at least 0.317 cm (1/8 inch) of lead shall be placed in the primary beam between the image receptor and the radiation measuring device. The lead or equivalent material shall be positioned to ensure that the entire primary beam is blocked and the radiation measuring device is positioned in accordance with the appropriate measurement protocol outlined in this subsection.

B) If the source is below the table, the exposure rate shall be measured 1 centimeter above the tabletop or cradle.

AGENCY NOTE: The fluoroscopic exposure rate may be measured at a reference point, in the central ray of the primary beam, other than specified in this subsection. However, compliance shall be determined by calculating the exposure rate at the point specified in this subsection.

C) If the source is above the table, the exposure rate shall be measured at 30 centimeters (12 inches) above the tabletop with the end of the beam-limiting device or spacer positioned as closely as possible to the point of measurement.

AGENCY NOTE: The fluoroscopic exposure rate may be measured at a reference point, in the central ray of the primary beam, other than specified in this subsection. However, compliance shall be determined by calculating the exposure rate at the point specified in this subsection.

D) For a fixed SID C-arm type of fluoroscope, the exposure rate shall be measured 30 centimeters (12 inches) from the input surface of the fluoroscopic imaging assembly.

AGENCY NOTE: The fluoroscopic exposure rate may be measured at a reference point, in the central ray of the primary beam, other than specified in this subsection. However, compliance shall be determined by calculating the exposure rate at the point specified in this subsection.

E) For a variable SID C-arm type of fluoroscope, the exposure rate shall be measured 30 centimeters (12 inches) 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.

AGENCY NOTE: The fluoroscopic exposure rate may be measured at a reference point, in the central ray of the primary beam, other than specified in this subsection. However, compliance shall be determined by calculating the exposure rate at the point specified in this subsection.

F) For a lateral type fluoroscope, the exposure rate shall be measured on the central axis of the primary beam at a point 15 centimeters (6 inches) 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 15 centimeters to the centerline of the x-ray table.

AGENCY NOTE: The fluoroscopic exposure rate may be measured at a reference point, in the central ray of the primary beam, other than specified in this subsection. However, compliance shall be determined by calculating the exposure rate at the point specified in this subsection.

AGENCY NOTE: A lateral type fluoroscope is a fluoroscope that cannot be rotated so that the source or the fluoroscopic imaging assembly can be positioned below the fluoroscopic table or cradle.

g) Screen Shielding - For systems without image intensifiers, the fluoroscopic screen shall be covered with transparent protective material having a lead equivalency of at least 1.5 millimeters for equipment capable of operating up to 100 kVp, at least 1.8 millimeters for equipment whose maximum operating potential is greater than 100 kVp and less than 125 kVp, and at least 2.0 millimeters for equipment whose maximum operating potential is 125 kVp or greater.

h) Staff and Ancillary Personnel Protection - The fluoroscopist, assistants and observers allowed in the examining room shall be protected from scatter radiation by protective aprons of not less than 0.25 millimeters lead equivalent or whole body protective barriers.

i) Additional Shielding - A shield of at least 0.25 millimeters lead equivalent, such as overlapping protective drapes or hinged or sliding panels, should be provided to intercept scatter radiation which would otherwise reach the fluoroscopist and others near the machine. This shielding shall not be a substitute for the wearing of a protective apron (0.25 mm lead equivalent for protection against scattered radiation).

j) Mobile Fluoroscopes - In addition to the other requirements of this Section, mobile fluoroscopes shall provide intensified imaging.

k) Radiation Therapy Simulation Systems - Radiation therapy simulation systems shall be exempt from the requirements of subsections (a), (b), (e) and (f) above provided that:

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; and

2) Such systems that do not meet the requirements of subsection (b) above 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.

l) Operator Restrictions - No person shall intentionally administer radiation to a human being with a fluoroscopic radiation machine unless such person is licensed to practice a treatment of human ailments under the Medical Practice Act of 1987, the Illinois Dental Practice Act, the Podiatric Medical Practice Act of 1987, and the Veterinary Medicine and Surgery Practice Act of 1983, except an accredited medical radiographer may operate a fluoroscope for static functions when interpretation of the results is not required and only under the direct supervision of a radiologist who is physically present.

(Source: Amended at 13 Ill. Reg. 803, effective April 1, 1989)

Section 360.60 Stationary Radiographic Systems Other Than Fluoroscopic, Dental Intraoral, Veterinary, or Systems Used Solely For Mammography

In addition to the provisions of Sections 360.10, 360.30 and 360.40, the requirements of this Section apply to x-ray equipment and associated facilities used for radiography with stationary radiographic systems other than fluoroscopic, dental intraoral, veterinary medical systems, or systems used solely for mammography.

a) Beam Limitation - The useful beam shall be limited to the area of clinical interest. The size of the image receptor utilized for each radiographic projection shall be consistent with the objectives of the examination.

1) Stationary General Purpose X-ray Systems - Means shall be provided to limit the x-ray field in the plane of the image receptor so that such field does not exceed each dimension of the image receptor by more than 2 percent of the SID when the axis of the x-ray beam is perpendicular to the plane of the image receptor.

A) Variable X-Ray Field Limitation - There shall be provided a means for stepless adjustment of the size of the x-ray field.

B) Visual Indication of Field Size - Means shall be provided for visually defining the perimeter of the x- ray field. The total misalignment of the edges of the visually defined field, with respect to the edges of the x-ray field, shall not exceed 2 percent of the distance from the source to the center of the visually defined field when the surface upon which it appears is perpendicular to the axis of the x-ray beam.

C) Numerical Indication of Field Size -

i) The beam-limiting device shall numerically indicate the x-ray field size in the plane of the image receptor to which it is adjusted.

ii) The x-ray field dimensions shall be specified in inches and/or centimeters, and shall be such that aperture adjustments result in x-ray field dimensions in the plane of the image receptor that do not differ from the numerical indicated dimensions by more than + or - 2 percent of the SID when the beam axis is perpendicular to the plane of the image receptor.

iii) The beam-limiting device shall be provided with SID scales that reflect the actual SID(s) used for radiographic procedures.

D) SID Indication -

i) Means shall be provided to indicate the SID.

ii) SIDs shall be indicated in inches and/or centimeters and the measured SID shall correspond to the indicated value to within 2 percent.

E) X-Ray Field/Image Receptor Alignment - Means shall be provided to:

i) Indicate when the axis of the x-ray field is perpendicular to the plane of the image receptor; and

ii) Align the center of the x-ray field with respect to the center of the image receptor to within 2 percent of the SID.

F) Additional Requirements for Systems Equipped with Positive Beam Limitation -

i) The x-ray field size in the plane of the image receptor, whether automatically or manually adjusted, shall be such that neither the length nor the width of the x-ray field differs from that of the image receptor by greater than 3 percent of the SID and that the sum of the length and width differences without regard to sign be no greater than 4 percent of the SID when the equipment indicates that the beam axis is perpendicular to the plane of the image receptor.

ii) The radiographic system shall be capable of operation, at the discretion of the operator, such that the field size at the image receptor can be adjusted to a size smaller than the image receptor. The minimum field size at a distance of 100 centimeters (40 inches) shall be equal to or less than 5 centimeters by 5 centimeters (2 inches by 2 inches). Return to positive beam limitation shall occur upon a change in image receptor.

iii) Positive beam limitation may be bypassed when radiography is conducted which does not use the cassette tray or permanently mounted vertical cassette holder, or when either the beam axis or table angulation is not within 10 degrees of the horizontal or vertical during any part of the exposure, or during stereoscopic radiography. If the bypass mode is provided, return to positive beam limitation shall be automatic.

iv) A capability may be provided for overriding positive beam limitation in the event of system failure or to perform special procedures which cannot be performed in the positive mode. If so provided, a key shall be required to override the positive mode. It shall be impossible to remove the key while the positive mode is overridden.

2) Special Purpose X-Ray Systems -

A) SID Indication -

i) Means shall be provided to indicate the SID.

ii) SIDs shall be indicated in inches and/or centimeters and the measured SID shall correspond to the indicated value to within 2 percent.

B) Means shall be provided to limit the x-ray field in the plane of the image receptor so that such field does not exceed each dimension of the image receptor by more than 2 percent of the SID when the axis of the x-ray beam is perpendicular to the plane of the image receptor.

C) Means shall be provided to align the center of the x- ray field with the center of the image receptor to within 2 percent of the SID.

D) The requirements of subsection (a)(2)(B) above may be met:

i) With a system that meets the requirements specified in subsection (a)(1) above; or

ii) With an assortment of removable, fixed-aperture, beam-limiting devices sufficient to meet the requirement for each combination of image receptor size and SID for which the unit is used, with each such device having permanent, clearly legible markings, in inches and/or centimeters, to indicate the image receptor size and SID for which it is designed; or

iii) With a beam-limiting device having multiple fixed apertures sufficient to meet the requirement for each combination of image receptor size and SID for which the unit is used. Permanent, clearly legible markings, in inches and/or centimeters, shall indicate the image receptor size and SID for which each aperture is designed and shall indicate which aperture is in position for use.

3) Single Purpose X-Ray Systems Designed for One Image Receptor Size - Radiographic equipment designed for only 1 image receptor size at a fixed SID shall be provided with means to limit the x-ray field at the plane of the image receptor to dimensions no greater than those of the image receptor when the axis of the x-ray beam is perpendicular to the plane of the image receptor.

b) Timers -

1) Means shall be provided to terminate the exposure at a preset time interval, preset product of current and time, preset number of pulses, or preset radiation exposure to the image receptor. Also, it shall not be possible to make an exposure when the timer is set to a zero or off position if either position is provided.

2) In addition, for certified systems, termination of exposure shall cause automatic resetting of the timer to its initial setting or to zero.

c) Operator's Control Station - Stationary protective barriers shall be provided for the x-ray operator.

d) Exposure Switch Arrangement - The exposure switch shall be arranged so that it cannot be operated by a person outside a stationary protective barrier.

e) Ancillary Personnel Protection - Individuals other than the patient whose presence is required in the radiographic room during an x-ray examination shall be protected from scatter radiation by protective aprons of not less than 0.25 millimeters lead equivalent or whole body protective barriers.

f) Medical Radiographic Exposure Limits - The exposure measured at the table top for the technique used for an average adult patient for routine medical radiography will be the following: (See Appendix A for measurement protocol).

1) "Abdomen Anterior Posterior (A.P.) View" exposure shall not exceed 500 milliroentgens per radiograph.

2) "Lumbar Spine Lateral View" exposure shall not exceed 1400 milliroentgens per radiograph.

3) "Cervical Spine A.P. View" exposure shall not exceed 150 milliroentgens per radiograph.

4) "Skull Posterior Anterior (P.A.) View" exposure shall not exceed 400 milliroentgens per radiograph.

AGENCY NOTE: These exposures are maximums. With careful selection of technique factors, adjustment of film processing systems, and choice of film and film screen combinations, patient exposures can be further reduced. For example, the following patient exposures should not be exceeded for each of the exams listed: "Abdomen A.P. View" exposure should not exceed 350 milliroentgens per radiograph; "Lumbar Spine Lateral View" exposure should not exceed 1,000 milliroentgens per radiograph; "Cervical Spine A.P. View" exposure should not exceed 100 milliroentgens per radiograph; and "Skull P.A. View" exposure should not exceed 200 milliroentgens per radiograph.

(Source: Amended at 15 Ill. Reg. 6180, effective April 16, 1991)

Section 360.70 Mobile/Portable Radiographic Systems Other Than Systems Used Solely For Mammography

In addition to the provisions of Sections 360.10, 360.30 and 360.40, the requirements of this Section apply to x-ray equipment and associated facilities used for radiography with medical mobile/portable systems.

a) Beam Limitation - The useful beam shall be limited to the area of clinical interest. The size of the image receptor used for each radiographic projection shall be consistent with the objectives of the examination.

1) Limitation Criteria - Means shall be provided to limit the x-ray field in the plane of the image receptor so that the field does not exceed each dimension of the image receptor by more than 2 percent of the SID when the axis of the x-ray beam is perpendicular to the plane of the image receptor. Limitation of the x-ray field for certified x-ray systems shall be accomplished by the means specified in Section 360.60(a)(1)(A) and (B). For non-certified x-ray systems, the x-ray field shall be limited by the means specified in either Section 360.60(a)(1)(A) and (B) or Section 360.60(a)(2)(D)(i) and (ii).

2) SID Indication -

A) Means shall be provided to indicate the SID.

B) SIDs shall be indicated in inches and/or centimeters and the measured SID shall correspond to the indicated value to within 2 percent.

b) Exposure Switch Arrangement -

1) The exposure control switch shall be arranged so that the

operator can stand at least 6 feet from the patient, the x- ray tube, and well away from the useful beam.

2) All individuals operating mobile/portable x-ray systems shall wear protective aprons of not less than 0.25 millimeters lead equivalent.

3) When a mobile/portable x-ray system is used in 1 location, it shall be considered a stationary system subject to the requirements specified in Section 360.60(c) and (d).

c) Source-Skin Distance -

1) Non-certified x-ray systems shall not be operable at a SSD of less than 20 centimeters (8 inches).

2) Certified x-ray systems shall not be operable at a SSD of less than 30 centimeters (12 inches).

d) Timers -

1) Means shall be provided to terminate the exposure at a preset time interval, preset product of current and time, preset number of pulses, or preset radiation exposure to the image receptor. Also, it shall not be possible to make an exposure when the timer is set to a zero or off position if either position is provided.

2) In addition, for certified systems, termination of exposure shall cause automatic resetting of the timer to its initial setting or to zero.

e) Radiation from Capacitor Energy Storage X-ray Equipment in Standby Status - Radiation emitted from the x-ray tube when the exposure switch or timer is not activated shall not exceed a rate of 2 milliroentgens per hour at 5 centimeters (2 inches) from any accessible surface of the diagnostic source assembly, with the beam-limiting device fully open.

f) Ancillary Personnel Protection - Individuals other than the patient whose presence is required in the radiographic room during an x-ray examination shall be protected from scatter radiation by protective aprons of not less than 0.25 millimeters lead equivalent or whole body protective barriers.

g) Medical radiographic Exposure Limits - Criteria specified in Section 360.60(f) apply.

(Source: Amended at 15 Ill. Reg. 6180, effective April 16, 1991)

Section 360.71 Requirements for Facilities Performing Mammography

In addition to the provisions of Sections 360.30, 360.40 and 32 Ill. Adm. Code 400 and 401, the requirements of this Section apply to mammography systems and associated facilities used for mammography.

a) Physician Supervision - Mammography operations and procedures shall be under the supervision of a physician licensed under the Medical Practice Act of 1987 (Ill. Rev. Stat. 1989, ch. 111, par. 4400) to practice medicine in all of its branches.

AGENCY NOTE: The individual interpreting clinical images of the breast should be a radiologist trained in the imaging modality being used and should be certified or eligible for certification by either the American Board of Radiology in diagnostic radiology or general radiology or the American Osteopathic Board of Radiology. A facility performing mammography should have a program that is accredited by the American College of Radiology or the Illinois Radiological Society or have a program that is comparable.

b) Screen-Film Mammography - Screen-film mammography shall only be performed with a special purpose radiation machine specifically designed for mammography procedures.

c) Xeromammography - Xeromammography shall only be performed with a radiation machine that has been specifically designed for or modified to perform xeromammography.

d) Beam Limitation -

1) Means shall be provided to limit the useful beam so that the x-ray field at the plane of the image receptor does not extend beyond any edge of the image receptor at any designated source to image receptor distance (SID). However, the x-ray field may extend beyond the edge of the image receptor designed to be adjacent to the chest wall provided it does not extend beyond this edge by more than 2 percent of the SID.

2) The requirement of subsection (d)(1) above shall be met with a system that performs as prescribed in either Section 360.60(a)(1) or Section 360.60(a)(2)(D)(ii).

e) Beam Limiting Device Labeling -

1) If beam limitation is met with a device as prescribed in Section 360.60(a)(2)(D)(ii), such device shall have permanent clearly legible markings in inches and/or centimeters indicating the image receptor size and SID for which each device is designed.

2) If the radiation machine is capable of using variable SIDs, the SID indication specified in subsection (e)(1) above shall be the maximum SID for which the beam limiting device is designed.

f) Exposure Switch Arrangement -

1) Stationary Mammography Systems - For mammography systems consisting of stationary x-ray equipment, the criteria specified in Section 360.60(d) shall apply.

2) Mobile and Portable Mammography Systems - For mammography systems consisting of mobile and portable x-ray equipment, the criteria specified in either Section 360.60(d) or Section 360.70(b)(1) shall apply.

g) Operator Shielding -

1) Stationary Mammography Systems - For mammography systems consisting of stationary x-ray equipment, the criteria specified in Section 360.60(c) shall apply.

2) Mobile and Portable Mammography Systems - For mammography systems consisting of mobile and portable x-ray equipment, the criteria specified in either Section 360.60(c) or Section 360.70(b)(2) shall apply.

3) Mobile and Portable X-Ray Equipment Used in Only One Location - When mobile or portable x-ray equipment is used in only one location, it shall be considered a stationary system and shall be subject to the requirements specified in Sections 360.60(c) and (d).

h) Timers - The criteria specified in Section 360.60(b) shall apply.

i) SID Indicator - For radiation machines capable of operating at variable SIDs, the criteria specified in Section 360.60(a)(1)(D) shall apply.

j) X-ray Field/Image Receptor Alignment - Section 360.60(a)(2)(C) shall apply.

k) Backup Timer - Radiation systems with automatic exposure control (AEC) shall incorporate a backup timer to terminate the radiation exposure in the event of AEC failure.

l) SSD - Except with respect to magnification for mammography projections, mammography systems shall satisfy the requirements of Section 360.70(c).

m) Focal Spot Size - The nominal focal spot size, as specified by the x-ray tube manufacturer, shall not exceed 0.7 millimeters.

n) Reproducibility of Exposures - For all systems, regardless of whether they are equipped with AEC, the estimated coefficient of variation of radiation exposures shall be no greater than 0.05 for any specific combination of selected technique factors. It will not be necessary to calculate the coefficient of variation if for 4 consecutive measurements taken within a time period of 1 hour the difference between the highest and lowest exposures does not exceed 10 percent. If there is a difference greater than 10 percent, 6 additional exposures shall be made and the coefficient of variation shall be calculated.

AGENCY NOTE: "Coefficient of variation" means the ratio of the standard deviation to the mean value of a population of observations. It is calculated using the following equation:

where:

s = Estimated standard deviation of the population.

X = Mean value of observations in sample.

Xi = ith observation sampled.

n = Number of observations sampled.

o) Mammography Exam Dose Limits (See Appendix B for the required measurement protocol.) - The mean glandular dose for one craniocaudal view of a 1.8 inch (4.5 centimeter) compressed breast (50 percent adipose/50 percent glandular) shall not exceed:

1) 100 millirads (1 milligray) for film/screen radiographs not employing the use of grids,

2) 300 millirads (3 milligrays) for film/screen radiographs employing the use of grids, or

3) 400 millirads (4 milligrays) for xerography.

AGENCY NOTE: A facility performing mammography should have a Mammography Dosimetry Test phantom specifically designed for breast imaging. This phantom should enable the individual interpreting clinical images of the breast to readily determine the x-ray system's ability to identify masses, fibrils, and calcifications on a month to month basis.

(Source: Added at 15 Ill. Reg. 6180, effective April 16, 1991)

Section 360.80 Photofluorographic Systems

In addition to the provisions of Sections 360.10, 360.30 and 360.40, the requirements of this Section apply to x-ray equipment and associated facilities used for photofluorography.

AGENCY NOTE: Photofluorography is frequently called mass miniature radiography. This is the method usually employed in projects such as chest x- rays for tuberculosis control. In this technique the image of a fluorescent screen is recorded on film by means of a camera. The film used is of small size. Some units use cut film 4 inches by 4 inches in size. More commonly, roll film is used; the film is usually 70-mm wide, but may be 90 or 100-mm.

a) Beam Limitation - Photofluorographic systems shall be provided with means to limit the x-ray field at the plane of the image receptor to dimensions no greater than those of the image receptor.

b) Operator Control Station - Criteria specified in Section 360.60(c) shall apply.

c) Exposure Switch Arrangement - Criteria Specified in Section 360.60(d) shall apply.

d) Timers -

1) Means shall be provided to terminate the exposure at a preset time interval, preset product of current and time, preset number of pulses, or preset radiation exposure to the image receptor. Also, it shall not be possible to make an exposure when the timer is set to a zero or off position if either position is provided.

2) In addition, for certified systems, termination of exposure shall cause automatic resetting of the timer to its initial setting or to zero.

e) Ancillary Personnel Protection - Other than the patient, individuals whose presence is required in the radiographic room during an x-ray examination shall be protected from scatter radiation by protective aprons of not less than 0.25 millimeters lead equivalent or whole body protective barriers.

f) Photofluorographic Exposure Limit - The exposure to an average patient shall not exceed 200 milliroentgens per photofluorograph (See Appendix A for measurement protocol).

AGENCY NOTE: The patient exposure for this procedure should not exceed 100 milliroentgens per photofluorograph.

g) Medical Supervision - The supervising physician shall outline responsibilities regarding the photofluorographic operating and patient screening procedures. The procedures shall be submitted to this Department in writing prior to utilization of the equipment. Operating and patient screening procedures shall include at a minimum the following:

1) Operator qualifications,

2) Operator supervision,

3) Methods of operating x-ray machines,

4) Patient age limit,

5) Frequency of exam,

6) Pregnancy cases, etc.

(Source: Amended at 13 Ill. Reg. 803, effective April 1, 1989)

Section 360.90 Intraoral Dental Radiographic Systems

In addition to the provisions of Sections 360.10, 360.30 and 360.40, the requirements of this Section apply to x-ray equipment and associated facilities used for intraoral dental radiography.

a) Beam Limitation - X-ray systems designed for use with an intraoral image receptor shall be provided with means to limit the x-ray field at the patient's face to the smallest area which is clinically necessary. The x-ray field striking the patient's face shall not exceed a circle 7.5 centimeters (3 inches) in diameter. Even though the beam shall be containable within a circle 7.5 centimeters in diameter, it may be a rectangular configuration.

1) Beam limitation shall be accomplished by a position indicating device that is operated and shielded. The device shall provide the same degree of shielding as the tube housing assembly.

2) The position indicating device shall provide a SSD of not less than 18 centimeters (7 inches) for systems operated above fifty (50) kVp or 10 centimeters (4 inches) for systems operated at fifty (50) kVp or below.

b) Timers -

1) Means shall be provided to terminate the exposure at a preset time interval, preset product of current and time, preset number of pulses, or preset radiation exposure to the image receptor. Also, it shall not be possible to make an exposure when the timer is set to a zero or off position if either position is provided.

2) In addition, for certified systems, termination of exposure shall cause automatic resetting of the timer to its initial setting or to zero.

c) Exposure Switch Arrangement/Operator Protection - The exposure switch shall be arranged so that the operator can be at least 6 feet from the patient and well away from the useful beam during an exposure.

AGENCY NOTE: The Department recommends that whenever practicable, the x-ray operator stand behind a protective barrier or be provided with a protective apron of not less than 0.25 millimeters lead equivalent.

d) Ancillary Personnel Protection - Other than the operator and the patient, individuals whose presence is required in the room during an x-ray examination shall be protected from stray radiation by protective aprons of not less than 0.25 millimeters lead equivalent or a protective barrier.

e) Dental Radiographic Exposure Limits (Single Film) - The entrance exposure to an adult patient for a routine intraoral bitewing exam shall not exceed the maximum limits specified in Table C.

(Source: Amended at 13 Ill. Reg. 803, effective April 1, 1989)

Section 360.100 Veterinary Radiographic Systems

In addition to the provisions of Sections 360.10, 360.30 and 360.40, the requirements of this Section apply to x-ray equipment and associated facilities used for radiography with veterinary systems.

a) Beam Limitation - The useful beam shall be limited to the area of clinical interest. The size of the image receptor used for each radiographic projection shall be consistent with the objectives of the examination.

1) Limitation Criteria - Means shall be provided to limit the x-ray field in the plane of the image receptor so that the field does not exceed each dimension of the image receptor by more than 2 percent of the SID when the axis of the x-ray beam is perpendicular to the plane of the image receptor.

2) Means shall be provided to align the center of the x-ray field with the center of the image receptor to within 2 percent of the SID.

3) The requirements of subsection (a)(1) above may be met with:

A) A system that meets the requirements specified in Section 360.60(a)(1); or

B) An assortment of removable, fixed-aperture, beam- limiting devices sufficient to meet the requirement for each combination of image receptor size and SID for which the unit is used, with each such device having permanent, clearly legible markings in inches

and/or centimeters, to indicate the image receptor size and SID for which it is designed; or

C) A beam-limiting device having multiple fixed apertures sufficient to meet the requirement for each combination of image receptor size and SID for which the unit is used. Permanent, clearly legible markings, in inches and/or centimeters, shall indicate the image receptor size and SID for which each aperture is designed and shall indicate which aperture is in position for use.

4) SID Indication -

A) Means shall be provided to indicate the SID.

B) SIDs shall be indicated in inches and/or centimeters and the measured SID shall correspond to the indicated value to within 2 percent.

b) Exposure Switch Arrangement -

1) The exposure control switch shall be arranged so the operator can be at least 6 feet from the patient, the x-ray tube, and well away from the useful beam.

2) All individuals operating veterinary x-ray systems shall wear protective aprons of not less than 0.25 millimeters lead equivalent or shall be protected from scatter radiation by a protective barrier.

c) Timers -

1) Means shall be provided to terminate the exposure at a preset time interval, preset product of current and time, preset number of pulses, or preset radiation exposure to the image receptor. Also, it shall not be possible to make an exposure when the timer is set to a zero or off position if either position is provided.

2) In addition, for certified systems, termination of exposure shall cause automatic resetting of the timer to its initial setting or to zero.

d) Radiation From Capacitor Energy Storage X-ray Equipment in Standby Status - Radiation emitted from the x-ray tube when the exposure switch or timer is not activated shall not exceed a rate of 2 milliroentgens per hour at 5 centimeters from any accessible surface of the diagnostic source assembly, with the beam-limiting device fully open.

e) Ancillary Personnel Protection - Individuals whose presence is required during an x-ray examination shall be protected from scatter radiation by protective aprons or gowns of not less than 0.25 millimeters lead equivalent or whole body protective barriers.

f) Veterinary Fluoroscopic Systems - All provisions of Section 360.50 apply except subsections (b) and (l).

(Source: Amended at 13 Ill. Reg. 803, effective April 1, 1989)

Section 360.110 Therapeutic X-Ray Installations

a) Equipment

1) Tube Housing -

A) The protective tube housing shall be of therapeutic- type, except in the case of "Contact" X-Ray Therapy (See Section 360.120(a)).

B) A therapeutic-type protective tube/target housing is defined as follows:

i) For x-ray therapy equipment not capable of operating at 500 kVp or above, the following definition applies: An x-ray tube housing so constructed that the leakage radiation at a distance of one meter from the source does not exceed one Roentgen in an hour when the tube is operated at its maximum rated continuous current for the maximum rated tube potential.

ii) For x-ray therapy equipment capable of operating at 500 kVp or above, the following definition applies: An x-ray tube housing so constructed that the leakage radiation at a distance of one meter from the source does not exceed either one Roentgen in an hour or 0.1 percent of the useful beam dose rate at one meter from the source, whichever is the greater when the machine is operated at its maximum rated continuous current for the maximum rated accelerating potential.

iii) In either case, small areas of reduced protection are acceptable provided the average reading over any 100 square centimeters area at one meter distance from the source does not exceed the values given above.

2) Collimation - The useful beam shall be collimated by means of cones, diaphragms or lead coverings to reduce the useful beam striking a patient to the smallest area which is clinically necessary.

3) Filtration - The filter system shall conform to recommended practices as defined in the current National Council on Radiation Protection Report No. 33, entitled "Medical X-Ray and Gamma Ray Protection for Energies up to 10 MeV, Equipment Design and Use".

4) Filtration Indicator - A filter indication system shall be used on all therapy machines using changeable filters. It shall be designed so as to permit easy recognition of any added filter in place. It shall indicate, from the control panel, the presence or absence of any filter.

5) Tube/Aperture Alignment - The x-ray tube shall be so mounted that it cannot turn or slide with respect to the housing aperture.

6) Tube Head Stability - Methods shall be provided to immobilize the tube housing during stationary portal treatment.

7) Preset Exposure Termination Device - A device (e.g. an automatic timer, exposure meter or dose meter) shall be provided to terminate the exposure after a preset time interval or preset exposure or dose limit. Methods shall be provided for the operator to terminate the exposure at any time.

8) Shutter Position Indicator - Equipment utilizing shutters to control the useful beam shall have a shutter position indicator on the control panel.

9) Positive Indicator - The control panel shall include a device (usually a milliammeter) which will give positive indication of the production of x-rays whenever the x-ray tube is energized.

10) Interlock - 150 kVp or Greater - A reliable interlock shall be installed on each door of the therapeutic room. This interlock shall be wired into the electrical circuit in such a manner that when the door is opened, for any reason, the x-ray exposure will automatically be terminated so that irradiation can be resumed only by manually resetting the controls on the control panel after the door is closed.

11) Door-Fastening Mechanism - If required, the door-fastening mechanism shall be installed so that the door can be opened from the inside in case of emergency.

12) Warning Lights - Treatment rooms to which access is possible through more than one entrance shall be provided with flashing warning lights in a readily observable position near the outside of all access doors, which will indicate when the useful beam is "on".

b) Operating Procedures.

1) All new facilities, and existing facilities not previously surveyed, shall have a protection survey made by, or under the direction of a qualified expert. This shall also be done after any change in the facility which might produce a radiation hazard. The expert shall report his findings in writing to the person in charge of the facility and a copy of this report shall be transmitted to the Department.

2) The facility shall be operated in compliance with any limitations indicated by the protection survey required by the Department.

3) When a patient must be held in position for radiation therapy, mechanical supporting or restraining devices shall be used whenever feasible.

4) Attendants - Below 120 kVp - No person, other than the attending physician or his assistant, shall be in the treatment room during exposure, except if in the opinion of the physician such attendance in the room is clinically necessary or desirable. If a person is required to hold or support the patient, no portion of such person shall be in the useful beam and such person shall be protected as much as is practicable from scattered radiation. The exposure of any person used for this purpose shall be monitored and a record maintained.

5) Attendants - 120 kVp or Greater - No person except the attending physician who works with ionizing radiation, shall be in the treatment room during exposure.

6) Communication with Patient - The control panel shall be arranged in such a manner that the operator can maintain aural and visual communication with the patient. Both the patient and the control panel shall be under observation of the operator during the entire exposure.

7) The output of each therapeutic x-ray machine shall be calibrated by, or under the direction of a qualified expert. The calibration shall be repeated after any change in or replacement of components of the x-ray output. Check calibrations shall be made at least once a year thereafter and be maintained by the registrant. Records of calibration shall be posted at the controls and shall include the date of calibration and the written signature of the qualified expert.

c) Structural Shielding.

1) Primary protective barriers shall be provided for any area that the useful beam may strike when using the largest possible diaphragm opening. Such barriers should extend at least one foot beyond the useful beam for any possible orientation.*

2) Secondary protective barriers shall be provided for all occupied areas exposed to leakage and scattered radiation.*

*Shall also conform with criteria outlined in NCRP Report No. 49 entitled "Structural Shielding Design and Evaluation for Medical Use of X-Ray and Gamma Rays of Energies Up to 10 MeV."

Section 360.120 Special Requirements for X-Ray Therapy Equipment Operated at Potential of Fifty (50) kVp and Below

a) Equipment.

1) All provisions of Section 360.110(a) apply except paragraphs(a)(10),(11) and (12), and except in the case of "Contact" x-ray tubes, where the leakage radiation at the surface of the housing shall not exceed 0.1 R/hr.

2) Preset Timer - Automatic timers shall be provided which will permit accurate presetting and termination of exposures as short as one second.

b) Operating Procedures.

1) In the therapeutic application of apparatus constructed with beryllium or other low-filtration windows, the registrant shall insure that the unfiltered radiation reaches only the part intended and that the useful beam is blocked at all time except when actually being used.

2) Machines having an output of more than 1,000 Roentgens per minute at any accessible place shall not be left unattended without the power being shut off at the main disconnect switch in addition to the control panel switch.

3) If the tube must be hand-held during irradiation the operator shall wear protective gloves and protective apron no less than 0.5 millimeter lead equivalent.

c) Structural Shielding.

In general, additional structural barriers will not be required. However, calculations of dose rates at critical positions beyond walls, partitions, etc., shall be made to determine if additional structural barriers will be required.

Section 360.APPENDIX A Medical Radiographic Exposure Limits

Measurement Protocol

The medical radiographic examinations specified in Section 360.60(f) are examinations frequently taken at medical radiation installations. The exposures measured using the "measurement protocol" are not actual "entrance exposures" to patients but should be considered "reference exposures" (patients are not involved in the measurement protocol).

a) An integrating exposure radiation measuring device is placed on the radiographic table-top directly in the center of the useful beam.

AGENCY NOTE: Applicable radiation measuring devices include but are not limited to: Condenser - R meter, low energy dosimeter (LED), integrating mode of a cutie-pie, thermoluminescent dosimetry (TLD).

AGENCY NOTE: In the event a patient support table is not utilized, (e.g., mobile/portable radiography) the measuring device should be placed directly in the center of the useful beam on any convenient support surface. The radiographic tube-to-measuring device distance shall be identical to the source-to-image receptor distance used during an actual patient exposure.

b) The radiographic tube is positioned identical to that used during an actual patient exposure (usually 40 inches to bucky).

c) The exposure technique is set up as follows:

1) For non-phototimed x-ray systems, the exposure technique used by the x-ray operator for an "average-sized" adult patient is set up on the controls.

EXAMPLE: A.P. Abdomen (80 kVp, 100 mAs). The useful beam is limited to the appropriate film size.

2) For phototimed x-ray systems, including photofluorographic systems, the exposure technique used by the x-ray operator for an "average sized" adult patient is set up on the controls. An appropriate phantom (simulating body attenuation) is placed in the useful beam between the radiation measuring device and the radiographic table-top or the surface of the photofluorographic screen assembly. The useful beam is limited to the size of the phantom.

d) A radiographic exposure is made (without patient) and the reading obtained from the radiation measuring device is recorded as a representative radiation exposure for that specific examination to determine compliance.

(Source: Amended at 13 Ill. Reg. 803, effective April 1, 1989) Section 360.APPENDIX B Mammography Dose Limit

MEASUREMENT PROTOCOL

The technique factors used for performing a mammography examination shall not permit the mean glandular absorbed dose to exceed the limits specified in Section 360.71(o).

The mammography exam dose limits are based on an average compressed breast value of 4.5 centimeters having an average density (i.e., 50 percent adipose and 50 percent glandular). While other sizes and densities may be present in the actual population of interest, this average compressed breast of 4.5 centimeters and density of 50 percent adipose and 50 percent glandular tissue will suffice as a dose model reference within the accuracies needed to provide safety to the general public.

a) Non-Automatic Exposure Control Systems - Perform the following steps to determine the mean glandular dose to a nominal 4.5 centimeter compressed breast:

1) Determine the x-ray tube target material.

2) Identify the curve which represents a 4.5 centimeter compressed breast thickness from the "Mammography Dose Evaluation" graph (see Illustration B).

3) Measure and record the x-ray system's useful beam half-value layer (HVL). (See Section 360.40(a).) Any compression device normally in the useful beam during mammography procedures shall be required to be placed between the x-ray tube target and measuring device when determining the HVL. The useful beam shall be collimated to a size encompassing the detector.

AGENCY NOTE: Filters used for the HVL evaluation should be placed as close to the target as possible. The HVL for film/screen mammography should not exceed 0.4 millimeters of aluminum equivalent and 1.6 millimeters of aluminum equivalent for xerography.

4) Estimate the normalized rad per roentgen factor from the "Mammography Dose Evaluation" graph (see Illustration B) using the coordinates for a 4.5 centimeter compressed breast thickness and the appropriate HVL.

Example: A radiation machine is provided with a molybdenum target and its HVL is determined to be 0.3. Therefore, for a 4.5 centimeter compressed breast, the normalized rad per roentgen factor would be 0.15.

5) Set the appropriate craniocaudal source to image receptor distance (SID) for the image receptor system used.

6) Place a radiation measuring device in the useful beam so that the center axis of the device is parallel to the breast support assembly (BSA). The geometric center of the measuring device shall be positioned so that it is centered 4.5 centimeters above the BSA, 2.54 centimeters (1 inch) from the chest wall edge of the BSA and at the center line of the BSA. (see Illustration A) The radiation measuring device shall be an integrating type appropriate to the high beam intensity and mammographic kilovoltage peak (kVp) used. No part of the device's detector area shall be outside of the useful beam.

7) Collimate the x-ray field to the size normally used.

8) Set the milliamperage (mA), kilovoltage peak (kVp) and exposure time technique factors normally used for a nominal 4.5 centimeter compressed breast.

9) Position in the useful beam any compression apparatus normally used.

10) Measure and record the exposure in air with the radiation measuring device.

11) Calculate the mean glandular dose for a 4.5 centimeter compressed breast by multiplying the measured exposure in roentgens by the normalized rads per roentgen figure established in subsection (a)(4) above.

Example: The rad (milligray) per roentgen figure of 0.15 established in subsection (a)(4) will be used. The measured roentgen output (subsection (a)(10) is determined to be 1.8 roentgens. Therefore, the mean glandular dose would be 288 millirads (2.88 milligrays). If the image receptor type used was film/screen with grid, the system would be in compliance with Section 360.71(o)(2).

b) Systems Equipped with AEC That Have A Means To Determine Exposure Elapsed Time - Perform one of the following two procedures to determine the mean glandular dose to a 4.5 centimeter compressed breast for systems equipped with either a milliamp second (mAs) meter or an exposure time indicator.

1) Mammography dosimetry test phantom procedure

A) Follow the procedures outlined in subsections (a)(1), (2), (3), (4) and (5) above.

B) Place a mammography dosimetry test phantom (see the definition for "Mammography dosimetry test phantom" in Section 360.20) on the breast support assembly. Center the phantom on the assembly to assure the phantom is over the automatic exposure control device(s).

C) Place a radiation measuring device in the useful beam so the center axis of the device is parallel to the breast support assembly (BSA). The geometric center of the measuring device shall be positioned so that it is centered 4.5 centimeters above the BSA, 2.54 centimeters (1 inch) from the chest wall edge of the BSA and immediately adjacent to either side of the breast dosimetry test phantom.

D) Collimate the x-ray field to the size normally used and assure that the area covered by the useful beam includes the breast dosimetry test phantom and the detector area of the radiation measuring device.

E) Set the milliamperage (mA) and kilovoltage peak (kVp) technique factors normally used for a nominal 4.5 centimeter compressed breast.

F) Position in the useful beam, any compression apparatus normally used.

G) Make an exposure and record the exposure indicated by the radiation measuring device.

H) Calculate the mean glandular dose for a 4.5 centimeter compressed breast. (See subsection (a)(11) above.)

2) Mammography test procedure without a mammography dosimetry test phantom.

A) Record for 30 consecutive days the patient characteristics in terms of mAs, compressed breast size and kVp per radiograph to determine an average. All patients radiographed during the 30 day period shall be included in the average. For the purpose of this protocol, breast size measurements shall be accurate to within 0.3 centimeters. The 4.5 centimeter compressed dimension is measured at a point midway between the medial and lateral edges of the breast and 1/2 the distance between the surface of the chest wall and the base of the nipple.

B) Calculate the average mAs and kVp associated with a nominal 4.5 centimeter compressed breast from the data recorded. The calculation may be either arithmetic or graphic.

AGENCY NOTE: A sample size of at least 30 will be considered an acceptable sample size for the purpose of determining the average mAs and kVp used for a nominal 4.5 centimeter compressed breast. If the sample size is less than 30, the graphic method of determining the average mAs and kVp shall be used.

C) Turn off the automatic exposure control system and set-up the x-ray system as specified in subsections (a)(1), (2), (3), (4), (5) and (6) above.

D) Collimate the x-ray field to the size normally used and assure that the area of the useful beam includes the detector area of the radiation measuring device.

E) Set the mAs and kVp as would be used if the automatic system was being used for a 4.5 centimeter compressed breast (i.e., based on the average technique factors calculated from subsection (b)(2)(B) above).

F) Position in the useful beam any compression apparatus normally used.

G) Perform the exposure measurement and calculate the mean glandular dose as specified in subsections (a)(10) and (11) above.

c) Systems Equipped with AEC That Do Not Have A Means To Determine Exposure Elapsed Time - Perform one of the following two procedures to determine the mean glandular dose to a nominal 4.5 centimeter compressed breast for systems not equipped with either an mAs or elapsed exposure time indicator:

1) Procedure No. 1 - No Mammography Dosimetry Test Phantom

A) Temporarily install either an mAs meter or elapsed exposure on-time indicator on the x-ray system. This installation shall be done by a person competent in electrical circuitry to avoid electrical hazards.

B) Follow the procedures listed under subsection (b)(2) above.

2) Procedure No. 2 - With a Dosimetry Test Phantom

Follow the procedures in subsection (b)(1) above.

(Source: Added at 15 Ill. Reg. 6180, effective April 16, 1991) Section 360.ILLUSTRATION A Thimble and Pancake Chamber - Radiation Measuring Device

(Source: Added at 15 Ill. Reg. 6180, effective April 16, 1991) Section 360.ILLUSTRATION B Mammography Dose Evaluation Graph

Working curves for evaluating the average glandular dose delivered by 1 R in air incident on a 4.5 centimeter compressed breast thickness (vertical axis) vs. first HVL in mmAl (horizontal axis). The solid line represents tungsten tube target data. The broken line represents molybdenum or molybdenum/ tungsten target tube data. (Excerpt from NCRP 85)

(Source: Added at 15 Ill. Reg. 6180, effective April 16, 1991) Section 360.TABLE A Filtration Required as a Function of Operating kVp (Repealed)

(Source: Repealed at 13 Ill. Reg. 803, effective April 1, 1989)

Section 360.TABLE B Half-Value Layer as a Function of Tube Potential

X-ray Tube Voltage (kilovolt peak) Minimum HVL (mm of Al) (1)

Indicated Specified Other Designed operating Operating Dental X-Ray range Potential (2) Systems (3) Systems (4)

Below 50 30 1.5 0.3 40 1.5 0.4 49 1.5 0.5

50 to 70 50 1.5 1.2 60 1.5 1.3 70 1.5 1.5

Above 71 71 2.1 2.1 80 2.3 2.3 90 2.5 2.5 100 2.7 2.7 110 3.0 3.0 120 3.2 3.2 130 3.5 3.5 140 3.8 3.8 150 4.1 4.1

(1) AGENCY NOTE: Linear extrapolation or interpolation may be made for an x-ray tube potential (kVp) not listed in Table B above (e.g., in the column entitled "Other X-ray Systems" operated at 20 kVp and 95 kVp, the minimum HVL required would be 0.2 and 2.6 mm of Al respectively).

(2) AGENCY NOTE: If the HVL determination for an x-ray system is below the minimum value specified for a given voltage, as indicated at the control panel, the actual kilovoltage should be measured and the HVL reevaluated.

(3) AGENCY NOTE: "Specified Dental Systems" means any dental x-ray system designed for use with intraoral image receptors and manufactured after December 1, 1980.

(4) AGENCY NOTE: "Other X-ray Systems" means all x-ray systems required to meet the provisions of Sections 360.50, 360.60, 360.70, 360.80, 360.90 (except "Specified Dental Systems") and 360.100.

(Source: Amended at 13 Ill. Reg. 803, effective April 1, 1989)

Section 360.TABLE C Entrance Exposure Limits Per Intraoral Bitewing Film

Operating Maximum Exposure (1) Minimum Exposure (2) (kVp) (milliroentgens) (milliroentgens)

45 640 430

50 600 400

55 560 370

60 520 320

65 480 270

70 440 220

75 400 175

80 360 140

85 320 115

90 280 100

95 240 95

100 200 90

(1) AGENCY NOTE: Linear extrapolation or interpolation may be made for an x-ray tube potential (kVp) not listed in Table B above (e.g., bitewing radiographs taken at 44 kVp and 72 kVp, the maximum entrance exposure permitted would be 648 milliroentgens and 424 milliroentgens respectively).

(2) AGENCY NOTE: The minimum exposures specified in the above table are included as recommendations only. They were empirically determined by a panel of dentists in a U.S. FDA, BRH study. They represent the minimum exposure which was found to be necessary to produce a diagnostic quality radiograph when a dental phantom, speed group "D" film, and adequate film development procedures were used. However, some x-ray units manufactured after 1980, or x-ray units used in conjunction with dental film of the ultra speed group "E", may be capable of generating exposures lower than listed in this table.

(Source: Amended at 15 Ill. Reg. 6180, effective April 16, 1991)