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For purposes of this section, mobile service operations means an x-ray unit of any type that is used in a van or similar vehicle to conduct x-ray examinations outside a fixed location. In addition to the requirements of 24 RCNY Health Code § 175.40, the applicant must provide the following information:
(a) an established main location where the machines, records, etc. will be maintained for inspection. This must be a street address, not a post office box number.
(b) a sketch or description of the normal configuration of each radiation machine's use, including the operator's position and any ancillary personnel's location during exposures. If a mobile van is used with a fixed unit inside, furnish the floor plan indicating protective shielding and the operator's location; and
(c) a current copy of the applicant's operating and safety procedures, including radiological practices for protection of patients, operators, employees and the general public.
(Added City Record 4/24/2019, eff. 5/24/2019)
(a) Any person who sells, leases, transfers, lends, disposes, assembles or installs radiation machines in New York City must notify the Department within 15 days of:
(1) the name and address of persons who have received these machines;
(2) the manufacturer, model, and serial number of each radiation machine transferred; and
(3) the date of transfer of each radiation machine.
(b) No person shall make, sell, lease, transfer, lend, assemble, or install radiation machines or the supplies used in connection with such machines unless such supplies and equipment when properly placed in operation meet the requirements of this Article and any other applicable law.
(c) The submission to the Department of FDA Form 2579 (Report of Assembly of a Diagnostic X-ray System) shall be deemed to meet all the requirements of this section.
(Added City Record 4/24/2019, eff. 5/24/2019)
(a) All surveys, audits, reports, or other work ("technical report") performed by a QMP or CRESO as required by this Article must be reviewed and signed by such QMP or CRESO.
(b) If the Department determines that any technical report of any QMP or CRESO providing services required by this Article are inadequate to assess radiation exposures, the Department may require such technical report to be revised or re-done according to specifications provided by the Department, or if this is not satisfactory, the Department may require the registrant or licensee to have such technical report performed by another QMP or CRESO. If the Department makes such a determination, it shall notify such QMP or CRESO of such determination and allow such QMP or CRESO an opportunity to be heard before the Department prior to any notification by the Department of its determinations, if any, to such individual's appropriate certifying agency.
(Added City Record 4/24/2019, eff. 5/24/2019)
(a) Stationary radiographic systems. Stationary radiographic systems must have the x- ray control, including the exposure switch, permanently mounted in a protected area so that the operator must remain in that protected area during the entire exposure.
(c) Dual-energy X-ray absorptiometry (DXA) systems are exempt from the requirements of this section, and must meet the requirements of 24 RCNY Health Code § 175.52.
(d) Space requirements.
(1) The operator must be allotted at least 0.70 m
2
(7.5 square feet) of unobstructed floor space in the booth;
(2) The operator's booth may be any geometric configuration with all dimensions at least 0.6 m (2 feet);
(3) Paragraphs (1) and (2) of this subdivision only apply to installations constructed after July 1, 2021.
(4) The space must not have any obstruction near the x-ray control panel, such as overhang, cables, or other similar obstructions;
(5) The booth must be located or constructed such that unattenuated direct scatter radiation originating on the examination table or at the wall-mounted image receptor will not reach the operator's position in the booth.
(e) Structural requirements.
(1) The booth walls must be permanently fixed barriers of at least 2.1 m (7 feet) high;
(2) When a door or movable panel is used as an integral part of the booth structure, it must have an interlock which will prevent an exposure when the door or panel is not closed;
(3) Shielding must be provided to meet the requirements for the occupational radiation exposure requirements of this Article.
(f) Radiation exposure control placement. The radiation exposure control for the system must be fixed within the booth and:
(1) must be at least 1.0 m (40 inches) from any point subject to direct scatter, leakage or primary beam radiation; and,
(2) must allow the operator to use the majority of the available viewing windows.
(g) Viewing system requirements. Each booth must have at least one viewing device which will:
(1) be so placed that the operator can view the patient during any exposure; and
(2) be so placed that the operator can have full view of any occupant of the room and should be so placed that the operator can view any entry into the room. If any door which allows access to the room cannot be seen from the booth, then outside that door there must be an "x-ray on" warning sign that will be lighted whenever an x-ray exposure is initiated. Alternatively, an interlock must be present such that exposures are prevented when the door is open.
(3) When the viewing system is a window, the following requirements also apply:
(i) the window must have a viewing area of at least 0.09 m
2
(1 square foot);
(ii) regardless of size or shape, at least 0.09 m
2
(1 square foot) of the window area must be centered no less than 0.6 m (2 feet) from the open edge of the booth and no less than 1.5 m (5.0 feet) from the floor;
(iii) the window must have at least the same lead equivalence as that required in the booth's wall in which it is mounted.
(4) When the viewing system is by mirrors, the mirrors must be located to allow the operator to view the patient during any exposure and allow full view of any occupant of, or entry into the room.
(5) When the viewing system is by electronic means, the camera shall be located to allow the operator to view the patient during any exposure and allow full view of any occupant of, or entry into the room.
(h) Mobile, portable, podiatric and dental radiographic installations (except CBCT), excluding mammographic systems.
(1) Mobile, portable, podiatric and dental x-ray equipment must allow an operator to stand at least 2 m (6.5 ft.) from the patient or behind a protective barrier of at least 2.1 m (7 feet) high, and not in the path of the primary x-ray beam whenever an x-ray exposure is initiated.
(2) Mobile and portable x-ray systems, excluding dental and podiatric systems, that are used continuously for greater than one week in the same location shall be deemed a fixed radiographic installation and must meet the operator protection standards for fixed radiographic equipment.
(3) Each operator of a mobile or portable radiographic x-ray unit, excluding dental and podiatric units, must be provided with personnel monitoring as provided in 24 RCNY Health Code § 175.17 and must wear a protective garment of at least 0.25 mm lead equivalent.
(i) Mammographic installations. The operator of the mammographic equipment must initiate x-ray exposures from the control console of the mammographic equipment with protective shielding for the operator that meets the following criteria:
(1) the shielding must be a height of 2.1 m (7 ft.) from the floor, with the lower edge not more than 7.5 cm (3 in.) from the floor. The shielding must be constructed as a permanent operator shield such that the operator can stand completely within the shielded area during the exposure; and
(2) the exposure control must be permanently fixed on the mammographic control console; and
(3) the operator must be able to communicate with and view the patient from the operator's protected position during the exposure.
(j) Operator protective garments.
(1) The facility must include a written policy and procedure in the quality assurance manual that conforms to the manufacturer's recommended care and use policy for lead protective garments and is adhered to on a continuing basis. This policy, at a minimum, must describe the training of Licensed Radiologic Technologists (LRTs) on the proper care and usage of protective garments; how storage sites for lead protective garments will be evaluated and maintained; and include procedures for how LRTs report lead protective garment problems to the radiation safety officer.
(2) All protective garments must be checked annually for defects such as holes (not including pinholes that do not affect the performance of the protective garment), cracks, and tears by using one or more of the following methods: visual investigation, tactile investigation, or x-ray imaging. Protective garments that are used by operators conducting fluoroscopic procedures must be checked using all three methods listed. If a defect is found, the lead protective garment must be removed from service and either replaced or repaired as needed to conform to the manufacturers' specifications.
(k) Radiation exposure control.
(1) Exposure initiation. Means must be provided to initiate the radiation exposure by a deliberate action on the part of the operator, such as the depression of a switch. Radiation exposure must not be initiated without such an action. In addition, it must not be possible to initiate an exposure when the timer is set to a "zero" or "off" position if either position is provided.
(2) Exposure indication. Means must be provided for visual indication observable at or from the operator's protected position whenever x-rays are produced. In addition, an audible signal to the operator must indicate that the exposure has terminated.
(l) Operator and ancillary personnel protection for veterinary systems. All stationary, mobile or portable x-ray systems used for veterinary work must be provided with either a 2 meter (6.5 feet) high protective barrier for operator protection during exposures, or must allow the operator to be at least 2 meters (6.5 feet) from the tube housing assembly during exposures. Otherwise, in cases where animals are held, the operator and ancillary personnel must be protected by a minimum of 0.25 mm lead equivalent from scatter radiation and 0.5 mm from the useful beam.
(Added City Record 4/24/2019, eff. 5/24/2019)
(a) All x-ray equipment must be installed and operated in accordance with the equipment manufacturer's specifications. If the registrant is required to have a QA program pursuant to 24 RCNY Health Code § 175.12(b)(1), and if the manufacturer's specifications are not available, the registrant's QMP or RSO must establish specifications for equipment use and document the specifications in the registrant's QA Manual. If the Department finds that the specifications present unacceptable tolerances, the Department shall require the registrant to utilize new specifications and shall notify the registrant of such in writing.
(b) All functional x-ray units registered by the Department shall be subject to inspection by Department staff, or by individuals directed by the Department to inspect such units, such as CRESOs.
(c) Radiation safety requirements. The registrant shall be responsible for directing the operation of the x-ray system under their administrative control and must assure that the requirements of this Article are met in the operation of the x-ray system.
(d) A current copy of 24 RCNY Health Code Article 175 must be maintained and readily accessible by the registrant either in hard copy or electronic format.
(e) Registrants required to have a QA program pursuant to 24 RCNY Health Code § 175.12(b)(1) must have a written radiation safety program as part of their QA program. The radiation safety program must include, but not be limited to, the following:
(1) that the use of ionizing radiation within its purview is performed in accordance with existing laws and regulations.
(2) that all persons are protected as required by this Article.
(3) that upon discovery of a medical event (as defined in this Article), the registrant must follow the applicable requirements of 24 RCNY Health Code § 175.25 concerning notification to the Department.
(f) If an x-ray system does not meet the provisions of this Article, then the registrant must correct such non-compliance, or initiate necessary corrective action, within 30 days of such discovery.
(g) Individuals operating the x-ray systems must meet all licensure, training and experience qualifications required by the Department.
(h) A sufficient number of protective apparel (e.g., aprons, gloves, collars) and shields must be available to provide the necessary radiation protection for all patients and personnel who are involved with x-ray operations.
(i) The registrant must use auxiliary equipment designed to minimize patient and personnel exposure commensurate with the needed diagnostic information.
(j) Neither the x-ray tube housing nor the collimating device shall be held during an exposure. Exceptions may be allowed for Department-approved devices specifically designed to be hand-held in the area of patient dental exams. The Department shall maintain a list of hand- held dental units that are approved for clinical exams in New York City, or may accept the list of such hand-held dental units as approved by New York State Department of Health, at the Department's discretion.
(k) The useful x-ray beam must be limited to the area of clinical interest. For x-ray units not utilizing PBL systems for clinical imaging and not using cones or diaphragms for beam restriction, the clinical x-ray field must be less than size of the image receptor on four of four sides of the image receptor. For all digital image receptors, the size of the clinical image must not be digitally manipulated as to render its original dimensions different from the clinical image size when the image is archived.
(l) Consideration must be given to selecting the appropriate technique and employing available dose reduction methods and technologies across all patient sizes and clinical indications. For registrants utilizing manual selection of technique settings for clinical x-ray exams, this means a technique chart that employs technique settings for thin, average and heavy patient sizes. In the case where children less than 18 years of age are radiographed, the minimal technique setting should correspond to patients of 1-years old, 5-years old and 10-years old for exams most likely to be administered, e.g., AP chest and abdomen exams. In all such cases, the Entrance Skin Exposure (ESE) must be directly or indirectly determined for all clinical techniques set. At a minimum, these technique charts along with ESEs must include:
(1) patient's (adult and pediatric, if appropriate) body part and anatomical size;
(2) technique factors;
(3) type of image receptor used;
(4) source to image receptor distance used (except for dental intraoral radiography), and
(5) position of the grid for the x-ray exam, i.e., the grid is either removed from the x-ray beam or is in the x-ray beam.
(m) A facility must have a documented procedure in place for verification of patient identity and exam to be performed, including identification of the appropriate body part.
(n) The registrant must create and make available to x-ray operators written safety procedures, including instructions for patient holding and any restrictions of the operating technique required for the safe operation of the particular x-ray system. The operator must be able to demonstrate familiarity with these procedures. Patient holding must be restricted to radiographic examinations with the exception that holding of patients shall be prohibited for all fluoroscopic exams and patient CT exams with the exception of hospital emergency rooms and hospital trauma centers.
(o) The registrant must restrict the presence of individuals in the x-ray room of the patient being examined to those required or in training for the medical procedure, or the parent or guardian of a patient while the x-ray tube is energized. Other than the patient being examined, the following applies to all individuals in the x-ray room:
(1) all persons must be positioned such that no part of the body will be struck by the useful beam unless protected by not less than 0.25 millimeter lead equivalent material;
(2) If the procedure results in secondary or scatter radiation in excess of 0.02 mSv (2 mrem) in any one hour at the position of these persons, they must be protected from the direct scatter radiation by whole body protective barriers of not less than 0.25 millimeter lead equivalent material or must be positioned so that the 0.02 mSv (2 mrem) in any one hour limit is met.
(p) Individuals must not be exposed to the useful beam except for healing arts purposes and unless such exposure has been authorized by a professional practitioner of the healing arts. This provision specifically prohibits deliberate exposure for the following purposes:
(1) exposure of an individual for training, demonstration, or other non-healing arts purposes; and
(2) exposure of an individual for the purpose of healing arts screening except as authorized by the Department.
(q) X-ray patient logbook. Each facility must maintain a written or electronic record containing the patient's name, the type of examinations, and the dates the examinations were performed for all radiographic (except dental, podiatric and veterinary exams) and fluoroscopic patient exams. The administration of contrast agents as part of the patient exam must be noted in the patient logbook to state that IV contrast was administered. All adverse effects to injected contrast agents must be reported to the NY State Health Department, as required by law.
(r) Sealing x-ray equipment. Sealing of x-ray units must be done only by the Department for x-ray units, of any type, that poses a hazard to the patient or the operator. No x- ray units sealed by the Department shall be put in use for clinical exams without the approval of the Department.
(s) Leakage radiation from the diagnostic source assembly. The leakage radiation from the diagnostic source assembly measured at a distance of 1 meter in any direction from the source must not exceed 0.88 milligray (mGy) air kerma (vice 100 milliroentgen (mR) exposure) in 1 hour when the x-ray tube is operated at its leakage technique factors. If the maximum rated peak tube potential of the tube housing assembly is greater than the maximum rated peak tube potential for the diagnostic source assembly, positive means must be provided to limit the maximum x-ray tube potential to that of the diagnostic source assembly.
(t) Technique indicators.
(1) For x-ray equipment capable of displaying technique factors, the technique factors to be used during an exposure must be indicated before the exposure begins. If automatic exposure controls are used, the technique factors which are set prior to the exposure must be indicated.
(2) The requirement of paragraph (1) of this subdivision may be met by permanent markings on equipment having fixed technique factors. Indication of technique factors must be visible from the operator's position except in the case of spot films made by the fluoroscopist.
(3) The accuracy of the technique factors for the x-ray unit (e.g., indicated kilovoltage peak (kVp), timer accuracy) must meet manufacturer specifications. In the absence of a manufacturer specification, the technique factor accuracy must be within ±10 percent.
(u) Beam quality.
(1) The half value layer (HVL) of the useful beam for a given x-ray tube potential shall not be less than the values shown in Table 1 of this subdivision. If it is necessary to determine such half-value layer at an x-ray tube potential which is not listed in Table 1, linear interpolation or extrapolation may be made. Positive means must be provided to ensure that at least the minimum filtration needed to achieve beam quality requirements is in the useful beam during each exposure. In the case of a system which is to be operated with more than one thickness of filtration, this requirement can be met by a filter interlocked with the kilovoltage selector which will prevent x-ray emissions if the minimum required filtration is not in place. In no case shall an x-ray unit failing to meet the minimum filtration standards in Table 1 conduct clinical patient exams until the x-ray unit is in compliance with Table 1.
TABLE 1*
X-Ray Tube Voltage (kilovolt peak) | ||||
Design Operating Range | Measured Operating Potential | Minimum HVL (mm in Aluminum) | ||
Specified Dental Systems 1 | Other X-Ray Systems (older) 2 | Other X-Ray Systems (newer) 3 | ||
X-Ray Tube Voltage (kilovolt peak) | ||||
Design Operating Range | Measured Operating Potential | Minimum HVL (mm in Aluminum) | ||
Specified Dental Systems 1 | Other X-Ray Systems (older) 2 | Other X-Ray Systems (newer) 3 | ||
Below 51 | 30 | 1.5 | 0.3 | 0.3 |
40 | 1.5 | 0.4 | 0.4 | |
50 | 1.5 | 0.5 | 0.5 | |
51 to 70 | 51 | 1.5 | 1.2 | 1.3 |
60 | 1.5 | 1.3 | 1.5 | |
70 | 1.5 | 1.5 | 1.8 | |
Above 70 | 71 | 2.1 | 2.1 | 2.5 |
80 | 2.3 | 2.3 | 2.9 | |
90 | 2.5 | 2.5 | 3.2 | |
100 | 2.7 | 2.7 | 3.6 | |
110 | 3.0 | 3.0 | 3.9 | |
120 | 3.2 | 3.2 | 4.3 | |
130 | 3.5 | 3.5 | 4.7 | |
140 | 3.8 | 3.8 | 5.0 | |
150 | 4.1 | 4.1 | 5.4 | |
1 Dental x-ray systems designed for use with intraoral image receptors and manufactured after December 1, 1980. 2 Dental x-ray systems designed for use with intraoral image receptors and manufactured before or on December 1,1980, and all other x-ray systems subject to this section and manufactured before June 10, 2006. 3 All x-ray systems, except dental x-ray systems designed for use with intraoral image receptors, subject to this section and manufactured on or after June 10, 2006. * Source: 21 C.F.R. § 1020.30(m) | ||||
(2) Measuring compliance. For capacitor energy storage equipment, compliance shall be determined with the maximum selectable quantity of charge per exposure.
(v) Battery charge indicator. On battery-powered generators, visual means must be provided on the control panel to indicate whether the battery is in a state of charge adequate for proper operation.
(w) Modification of certified diagnostic x-ray components and systems.
(1) Diagnostic x-ray components and systems certified in accordance with 21 C.F.R. Part 1020 must not be modified except with certified components.
(2) The owner who causes such modification must record the date and the details of the modification in the system records and maintain this information, and the modification of the x-ray system must not result in a failure to comply with this Article.
(x) Multiple tubes. Where two or more radiographic tubes are controlled by one exposure switch, the tube which has been selected must be clearly indicated prior to initiation of the exposure. Only the selected tube can be energized. This indication must be both on the x-ray control panel and at or near the tube housing assembly which has been selected.
(y) Mechanical support of tube head. The tube housing assembly supports must 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.
(z) Locks. All position locking, holding, and centering devices on x-ray system components and systems must function as intended.
(aa) Maintaining compliance. Diagnostic x-ray systems and their associated components used on humans and certified pursuant to the Federal Performance Standard for Diagnostic X-Ray Systems (21 C.F.R. § 1020.30) must be maintained in compliance with applicable requirements of that standard.
(Added City Record 4/24/2019, eff. 5/24/2019)
The requirements of this section apply to all non-dental registrants using diagnostic x-ray equipment.
(a) Acceptance testing. Each registrant must have acceptance testing conducted on all radiographic x-ray units with the exception of dental, podiatric, and bone densitometer units, prior to clinical patient exams being conducted with the designated x-ray units. The acceptance testing must be conducted by a QMP and the report must be provided to the registrant. All non- compliance issues noted in this report must be corrected prior to clinical use of the unit. The acceptance testing report must verify the stated manufacturer's tolerances for all machine testing. If manufacturer tolerances are absent, the registrant's QMP must develop tolerances that must be used in subsequent QA testing by the registrant and must be so noted in the quality assurance manual.
(b) Control and indication of technique factors.
(1) Timers. Means must be provided to terminate the exposure at a preset time interval, a preset product of current and time, a preset number of pulses, or a preset radiation exposure to the image receptor.
(i) Except during serial radiography, the operator must be able to terminate the exposure at any time during an exposure of greater than one-half second. Except during panoramic dental radiography, termination of exposure must cause automatic resetting of the timer to its initial setting or to zero. It must not be possible to make an exposure when the timer is set to a zero or off position if either position is provided.
(ii) During serial radiography, the operator must be able to terminate the x-ray exposure at any time, but means may be provided to permit completion of any single exposure of the series in process.
(2) Automatic exposure controls. When an automatic exposure control is provided:
(i) indication must be made on the control panel when this mode of operation is selected;
(ii) when the x-ray tube potential is equal to or greater than 51 kilovolts peak (kVp), the minimum exposure time for field emission equipment rated for pulse operation must be equal to or less than a time interval equivalent to two pulses and the minimum exposure time for all other equipment must be equal to or less than 1/60 second or a time interval required to deliver 5 milliampere-seconds (mAs), whichever is greater;
(iii) either the product of peak x-ray tube potential, current, and exposure time must be limited to not more than 60 kilowatt-seconds (kWs) per exposure or the product of x-ray tube current and exposure time must be limited to not more than 600 mAs per exposure, except when the x-ray tube potential is less than 51 kVp, in which case the product of x-ray tube current and exposure time must be limited to not more than 2,000 mAs per exposure; and
(iv) a visible signal must indicate when an exposure has been terminated at the limits described in subparagraph (iii) of this paragraph, and manual resetting must be required before further automatically timed exposures can be made.
(c) Reproducibility.
(1) Coefficient of variation. For any specific combination of selected technique factors, the estimated coefficient of variation of the air kerma must be no greater than 0.05.
(2) Measuring compliance. Determination of compliance must be based on 10 consecutive measurements taken within a time period of 1 hour. Equipment manufactured after September 5, 1978, must also have all variable controls for technique factors adjusted to alternate settings and reset to the test setting after each measurement. For equipment having automatic exposure controls, compliance shall be determined with a sufficient thickness of attenuating material in the useful beam such that the technique factors can be adjusted to provide individual exposures of a minimum of 12 pulses on field emission equipment rated for pulsed operation or no less than one-tenth second per exposure on all other equipment.
(3) Alternatively, the reproducibility of any technique value may be determined by taking 5 consecutive measurements and utilizing the formula given below:
Reproducibility = (maximum measured value - minimum measured value)
Average of the measured five values
The calculated reproducibility shall be equal to ± 10 percent for compliance.
(d) Linearity. The following requirements apply for any fixed x-ray tube potential within the range of 40 percent to 100 percent of the maximum rated. In regard to paragraphs (1) through (3) in this subdivision below, measurements can be made in mR instead of mGy.
(1) Equipment having independent selection of x-ray tube current (mA). The average ratios of air kerma to the indicated milliampere-seconds product (mGy/mAs) obtained at any two consecutive tube current settings must not differ by more than 0.10 times their sum. This is: |X1 - X2 ≤ | 0.10(X1 + X2); where X1 and X2 are the average mGy/mAs values obtained at each of two consecutive mAs selector settings or at two settings differing by no more than a factor of 2 where the mAs selector provides continuous selection.
(2) Equipment having selection of x-ray tube current-exposure time product (mAs). For equipment manufactured after May 3, 1994, the average ratios of air kerma to the indicated milliampere-seconds product (mGy/mAs) obtained at any two consecutive mAs selector settings must not differ by more than 0.10 times their sum. This is: |X1 - X2 ≤ | 0.10(X1 + X2); where X1 and X2 are the average mGy/mAs values obtained at each of two consecutive mAs selector settings or at two settings differing by no more than a factor of 2 where the mAs selector provides continuous selection.
(3) Measuring compliance. Determination of compliance will be based on at least 3 exposures, made within 1 hour, at each of the two settings. These two settings may include any two focal spot sizes except where one is equal to or less than 0.45 mm and the other is greater than 0.45 mm. For purposes of this requirement, focal spot size is the focal spot size specified by the x-ray tube manufacturer.
(e) Field limitation and alignment for mobile, portable, and stationary general purpose x-ray systems. Except when spot-film devices are in service, mobile, portable, and stationary general purpose radiographic x-ray systems must meet the following requirements:
(1) Variable x-ray field limitation. A means for stepless adjustment of the size of the x-ray field must be provided. Each dimension of the minimum field size at an SID of 100 cm must be equal to or less than 5 cm.
(2) Visual definition.
(i) Means for visually defining the perimeter of the x-ray field must be provided. The total misalignment of the edges of the visually defined field with the respective edges of the x-ray field along either the length or width of the visually defined field must 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.
(ii) When a light localizer is used to define the x-ray field, it must provide an average illuminance of not less than 160 lux (15 footcandles) at 100 cm or at the maximum SID, whichever is less. The average illuminance shall be based on measurements made in the approximate center of each quadrant of the light field. Radiation therapy simulation systems are exempt from this requirement.
(iii) The edge of the light field at 100 cm or at the maximum SID, whichever is less, must have a contrast ratio, corrected for ambient lighting, of not less than 4 in the case of beam-limiting devices designed for use on stationary equipment, and a contrast ratio of not less than 3 in the case of beam-limiting devices designed for use on mobile and portable equipment. The contrast ratio is defined as I1/I2, where I1 is the illuminance 3 mm from the edge of the light field toward the center of the field; and I2 is the illuminance 3 mm from the edge of the light field away from the center of the field.
(f) Field indication and alignment on stationary general purpose x-ray equipment. Except when spot-film devices are in service, stationary general purpose x-ray systems must meet the following requirements, in addition to those prescribed in subdivision (e) of this section:
(1) Means must be provided to indicate when the axis of the x-ray beam is perpendicular to the plane of the image receptor, to align the center of the x-ray field with respect to the center of the image receptor to within 2 percent of the SID, and to indicate the SID to within 2 percent;
(2) The beam-limiting device must numerically indicate the field size in the plane of the image receptor to which it is adjusted;
(3) Indication of field size dimensions and SIDs must be specified in centimeters or inches and must be such that aperture adjustments result in x-ray field dimensions in the plane of the image receptor which correspond to those indicated by the beam-limiting device to within 2 percent of the SID when the beam axis is indicated to be perpendicular to the plane of the image receptor; and
(4) Compliance measurements will be made at each SID in common clinical use (such as SIDs of 100, 150, and 200 cm or 36, 40, 48, 72 inches) and with at least one of the commonly used image receptor dimensions (such as nominal image receptor dimensions of 13, 18, 24, 30, 35, 40, and 43 cm or 5, 7, 8, 9, 10, 11, 12, 14, and 17 inches), or at any other specific dimensions at which the beam-limiting device or its associated diagnostic x-ray system is uniquely designed to operate.
(g) Field limitation on x-ray equipment other than general purpose radiographic systems.
(1) X-ray systems designed for one image receptor size. Radiographic equipment designed for only one image receptor size at a fixed SID must be provided with means to limit the field at the plane of the image receptor to dimensions no greater than those of the image receptor, and to align the center of the x-ray field with the center of image receptor to within 2 percent of the SID, or must be provided with means to both size and align the x-ray field such that the x-ray field at the plane of the image receptor does not extend beyond the edge of the image receptor.
(2) Other x-ray systems. Radiographic systems not specifically covered in subdivisions (e) and (f) of this section, and paragraph (1) of this subdivision, which are also designed for use with extraoral image receptors and when used with an extraoral image receptor, must be provided with means 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. In addition, means must 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, or means must be provided to both size and align the x-ray field such that the x-ray field at the plane of the image receptor does not extend beyond any edge of the image receptor. These requirements may be met with:
(i) A system which performs in accordance with subdivisions (e) and (f) of this section or when alignment means are also provided, may be met with either;
(ii) 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 designed. Each such device must have clear and permanent markings to indicate the image receptor size and SID for which it is designed; or
(iii) 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 designed. Permanent, clearly legible markings must indicate the image receptor size and SID for which each aperture is designed and must indicate which aperture is in position for use.
(h) Positive beam limitation (PBL). The requirements of this subdivision apply to radiographic systems which contain PBL and which the registrant has not disabled.
(1) Field size. When a PBL system is provided, it must prevent x-ray production when:
(i) Either the length or width of the x-ray field in the plane of the image receptor differs from the corresponding image receptor dimension by more than 3 percent of the SID; or
(ii) The sum of the length and width differences stated in subparagraph (i) of this paragraph without regard to sign exceeds 4 percent of the SID.
(iii) The beam-limiting device is at an SID for which PBL is not designed for sizing.
(2) Conditions for PBL. When provided and if the registrant has not disabled it, the PBL system must function as described in subparagraph (i) of paragraph (1) of this subdivision. whenever all the following conditions are met:
(i) The image receptor is inserted into a permanently mounted cassette holder;
(ii) The image receptor length and width are less than 50 cm;
(iii) The x-ray beam axis is within ±3 degrees of vertical and the SID is 90 cm to 130 cm inclusive; or the x-ray beam axis is within ±3 degrees of horizontal and the SID is 90 cm to 205 cm inclusive;
(iv) The x-ray beam axis is perpendicular to the plane of the image receptor to within ±3 degrees; and
(v) Neither tomographic nor stereoscopic radiography is being performed.
(3) Measuring compliance. Compliance with the requirements of subparagraph (i) of paragraph (1) of this subdivision shall be determined when the equipment indicates that the beam axis is perpendicular to the plane of the image receptor and the provisions of paragraph (2) of this subdivision are met. Compliance shall be determined no sooner than 5 seconds after insertion of the image receptor.
(4) Operator initiated undersizing. The PBL system must be capable of operating such that, at the discretion of the operator, the size of the field may be made smaller than the size of the image receptor through stepless adjustment of the field size. Each dimension of the minimum field size at an SID of 100 cm must be equal to or less than 5 cm. Return to PBL function as described in paragraph (1) of this subdivision must occur automatically upon any change of image receptor size or SID.
(5) Override of PBL. A capability may be provided for overriding PBL in case of system failure and for servicing the system. This override may be for all SIDs and image receptor sizes. A key must be required for any override capability that is accessible to the operator. It must not be possible to remove the key while PBL is overridden. Each such key switch or key must be clearly and durably labeled as follows: "For X-Ray Field Limitation System Failure". The override capability is considered accessible to the operator if it is referenced in the operator's manual or in other material intended for the operator or if its location is such that the operator would consider it part of the operational controls.
(6) Disabling of PBL. A facility has the option to permanently functionally disable a PBL system. When this option is chosen, the standards for manual collimation apply.
(i) Source-skin distance. The minimum source-skin distance must not be less than 30 cm, except intraoral dental equipment regardless of clinical or veterinary use.
(j) Radiation from capacitor energy storage equipment. Radiation emitted from the x-ray tube must not exceed:
(1) an air kerma of 0.26 microGy (vice 0.03 mR exposure) in 1 minute at 5 cm from any accessible surface of the diagnostic source assembly, with the beam-limiting device fully open, the system fully charged, and the exposure switch, timer, or any discharge mechanism not activated ; and
(2) an air kerma of 0.88 mGy (vice 100 mR exposure) in one hour at 100 cm from the x-ray source, with beam-limiting device fully open, when the system is discharged through the x-ray tube either manually or automatically by use of a discharge switch or deactivation of the input power. Compliance shall be determined by measurements of the maximum air kerma per discharge multiplied by the total number of discharges in 1 hour (duty cycle).
(k) Tube stands for portable x-ray systems. Except during veterinary field operations where it is impractical to do so, a tube stand or other mechanical support must be used for portable x-ray systems, so that the x-ray tube housing assembly need not be hand-held during an exposure.
(l) Conditions of use.
(1) The x-ray image receptor used as recording medium during the x-ray examination must show visual evidence of cut-off (beam delineation) on all four sides of the x- ray image. This applies to all x-ray units using manual collimation and where no positive means are used to contain the x-ray field to the size of the image receptor. The x-ray image receptor can be film or digital image receptors.
(2) Personnel monitoring must be required for all persons operating mobile or portable x-ray equipment, except hand-held dental x-ray units.
(3) No person shall be regularly employed to hold patients during exposures nor shall such duty be performed by an individual occupationally exposed to radiation in the course of that individual's other duties. When it is necessary to immobilize the patient, mechanical supporting or immobilizing devices should be used. Written safety procedures must provide the selection criteria for the holder and protocol to be followed during the patient holding procedure.
(4) If patients must be held by an individual, that individual must be instructed in personal radiation safety and must be protected with appropriate shielding devices such as protective gloves and a protective garment of at least 0.25 mm lead equivalent. No part of the holding individual's body shall be in the useful beam. The exposure of any individual used for holding patients must be monitored.
(5) For patients who have not passed the reproductive age, gonadal shielding of not less than 0.5 mm lead equivalent must be used during radiographic procedures in which the gonads are in the useful beam, except for cases in which this would interfere with the diagnostic procedure.
(6) Pregnant women and individuals under 18 years of age must not hold patients under any conditions.
(Added City Record 4/24/2019, eff. 5/24/2019)
(a) The following specific quality assurance requirements apply to a dental facility:
(1) If using a filmless system, maintain and operate PSP and DDR systems according to manufacturer specifications.
(2) The registrant must provide initial training and annual evaluations of x-ray operators to include but not limited to: positioning of the x-ray tube, image processing, operator location during x-ray exposure, source to skin distance, radiation protection, appropriate radiographic protocol and applicable regulatory requirements. Records of training and annual evaluations must be maintained for inspection by the Department.
(b) Warning label.
(1) On systems manufactured on or before June 10, 2006, the control panel containing the main power switch must bear the following warning statement, or the warning statement in paragraph (2) of this subdivision, legible and accessible to view: "WARNING: This x-ray unit may be dangerous to patient and operator unless safe exposure factors and operating instructions are observed."
(2) On systems manufactured after June 10, 2006, the control panel containing the main power switch must bear the warning statement, legible and accessible to view: "WARNING: This x-ray unit may be dangerous to patient and operator unless safe exposure factors, operating instructions and maintenance schedules are observed."
(c) Radiation exposure control. Means must be provided to initiate the radiation exposure by a deliberate action on the part of the operator, such as the depression of a switch. Radiation exposure must not be initiated without such an action.
(d) Exposure control location and operator protection. Except for units designed to be hand-held, the exposure control must allow the operator to be:
(1) behind a protective barrier at least 2 meters (6.5 feet) tall, or
(2) at least 2 meters (6.5 feet) from the tube housing assembly, outside the path of the useful x-ray beam, while making exposures.
(e) Administrative controls.
(1) Patient and image receptor holding devices must be used when the techniques permit.
(2) Except for units designed to be hand-held, the tube housing and position indicating device (PID) must not be hand-held during an exposure.
(f) Hand-held intraoral equipment. In addition to other requirements in this Article, the following applies specifically to hand-held devices:
(1) The hand-held x-ray system must be equipped with a backscatter shield of not less than 0.25 mm lead equivalent and 15.2 cm (6 inches) in diameter that is positioned as close as practicable to the distal end of the position indication device.
(2) The facility must maintain documentation that each operator has completed training as specified by the manufacturer.
(3) The facility must adopt and follow protocols provided by the manufacturer, and approved by the Department, regarding the safe operation of the device.
(4) When operating a hand-held intraoral dental radiographic unit, operators must wear a 0.25 mm lead equivalent apron.
(5) If the operator has difficulty in holding the device stationary during the exposure, the operator shall use a stand to immobilize the device.
(6) The registrant must secure the hand-held device from unauthorized removal or use.
(g) Beam-on indicators. The x-ray control must provide visual indication whenever x- rays are produced. In addition, for certified x-ray units, a signal audible to the operator must indicate that the exposure has terminated.
(h) Multiple tubes. Where two or more radiographic tubes are controlled by one exposure switch, the tube which has been selected must be clearly indicated prior to initiation of the exposure. Only the selected tube can be energized. This indication must be both on the x-ray control panel and at or near the tube housing assembly which has been selected.
(i) Mechanical support of tube head. The tube housing assembly supports must 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.
(j) Battery charge indicator. On battery-powered generators, visual means must be provided on the control panel to indicate whether the battery is in a state of charge adequate for proper operation.
(k) Technique indicators.
(1) For x-ray equipment capable of displaying technique factors, the technique factors to be used during an exposure must be indicated before the exposure begins.
(2) The requirement of paragraph (1) of this subdivision may be met by permanent markings on equipment having fixed technique factors.
(l) Exposure reproducibility. For any specific combination of selected technique factors, the estimated coefficient of variation of the air kerma must be no greater than 0.05.
(m) Timers. Means must be provided to terminate the exposure at a preset time interval, a preset product of current and time, a preset number of pulses, or a preset radiation exposure to the image receptor.
(n) Kilovolt peak. At a minimum, the kVp must be accurate to within 10 percent on variable kVp units and within 20 percent on fixed kVp units.
(o) X-ray beam alignment.
(1) The useful x-ray beam must be limited to the area of clinical interest.
(2) Intraoral dental units.
(i) X-ray systems designed for use with an intraoral image receptor must be provided with means to limit the source-to-skin distance (SSD) to not less than 18 cm.
(ii) The x-ray field at the minimum SSD must be containable in a circle having a diameter of no more than 7 cm.
(3) Extraoral, panoramic and cephalometric units. X-ray systems designed for use with extraoral image receptors and when used with an extraoral image receptor, must be provided with means 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. In addition, means must 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, or means must be provided to both size and align the x-ray field such that the x-ray field at the plane of the image receptor does not extend beyond any edge of the image receptor. These requirements may be met with:
(i) 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 designed. Each such device must have clear and permanent markings to indicate the image receptor size and SID for which it is designed; or
(ii) 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 designed. Permanent, clearly legible markings must indicate the image receptor size and SID for which each aperture is designed and must indicate which aperture is in position for use.
(p) Beam quality. The Half Value Layer (HVL) of the useful beam for a given x-ray tube potential must not be less than the values shown in Table 1 of 24 RCNY Health Code § 175.47(u). If it is necessary to determine such half-value layer at an x-ray tube potential which is not listed in Table 1, linear interpolation or extrapolation may be made.
(q) Conditions of use.
(1) The x-ray system must always be operated in such a manner that the useful beam at the patient's skin does not exceed the requirements of paragraph (2) of subdivision (o) of this section.
(2) The operator shall position the end of the position indicating device (PID) within 1 cm (0.4 in.) of the skin of the patient, if such device is routinely used in conducting dental radiography.
(3) Time-temperature techniques or automatic processing must be used to develop pre-operative diagnostic dental x-ray films. Processing techniques must be consistent with those recommended by the x-ray film manufacturer. Sight developing of dental radiographs is prohibited except for films taken during operative procedures.
(4) Dental x-ray exposure technique factors and dental processing conditions must yield entrance skin exposure (ESE) values for the bitewing x-ray projection that are identical to or do not exceed the maximum range of ESE values for dental "D" and "E" speed film designations as published in HHS document #FDA-85-8245 (August 1985) or superseding documents. With respect to maximum ESE values for digital image receptors (are deemed to be either Computed Radiography (CR) or Digital Image Receptors (DR)), digital image receptors shall be deemed to be equivalent to "E" speed film.
(r) Facilities possessing a Cone Beam Computed Tomography (CBCT) unit.
(1) Notwithstanding anything in this Article to the contrary, dental facilities possessing a CBCT unit must develop and maintain a written quality assurance program, including a written QA manual and a written radiation safety policy and procedures manual for all CBCT dental equipment possessed by the facility.
(i) For all dental CBCT units, the registrant must establish annual QA testing of x-ray parameters sufficient to maintain patient doses and image quality consistent over time. The annual tests will evaluate, at a minimum, collimation, filtration, patient dose, accuracy and reproducibility of x-ray techniques and the operational status of x-ray safety features.
(ii) For all CBCT units, the QA tests must follow the manufacturer's recommended tests and frequency and utilize the manufacturer's QA phantom. The QA test results will be retained for review by the Department for 5 years, the facility must establish QA testing that includes, at a minimum, the manufacturer's recommended QA tests plus the additional QA tests described in subparagraph (iii) of this subdivision.
(iii) Semi-annual QA tests to determine image noise, image uniformity, reconstructed image measurement accuracy, high contrast spatial resolution of the CBCT unit.
(iv) Dental facilities possessing a CBCT unit must use a medical physicist who is a QMP in performing its QA activities.
(2) Dental facilities possessing CBCT equipment must annually determine the patient radiation dose (using direct measurement or indirect means to estimate dose) for the most common CBCT scan used at the facility as conducted by a QMP.
(3) Dental facilities possessing CBCT equipment must conduct annual QA tests to measure reproducibility of imaging parameters (kVp, exposure time and dimensions of the scan beam), reproducibility of exposure per the most common scan and beam filtration (HVL).
(4) Conditions of operation for the CBCT unit.
(ii) All operators of the CBCT must undergo training on the proper operation of the CBCT units and documentation of this training must be retained by the dental facility for review by the Department until after the next scheduled inspection is completed by the Department.
(iii) All operators must be able to communicate with and visually observe the patient during the CBCT examination from the operator's protected position.
(iv) CBCT patient exams will not be conducted solely for cosmetic purposes with no diagnostic value to the patient.
(v) The logbook for CBCT exams must contain all relevant diagnostic examination information, including but not limited to, x-ray technique, scan time, anatomical exam site and reason for examination.
(Added City Record 4/24/2019, eff. 5/24/2019)
(a) Equipment. Collimating devices capable of restricting the useful beam to the area of clinical interest must be used. The x-ray films or image receptor used as the recording medium during the x-ray examination must show substantial evidence of cut-off (beam delineation). A device must be provided which terminates the exposure after a preset time interval or exposure. The exposure switch must be of the dead-man type and where protective barriers are required must be so arranged that it cannot be operated outside the shielded area.
(b) Each installation must be arranged so that the operator can stand at least 2 meters (6.5 feet) from the patient, the x-ray tube and the useful beam during exposure. A protective barrier must be provided when the operator cannot stand at least 2 meters (6.5 feet) away from the patient, the x-ray tube and the useful beam during exposures.
(c) No person shall hold film during the exposure. Only persons required for the radiographic procedure must be in the radiographic room during exposure.
(Added City Record 4/24/2019, eff. 5/24/2019)
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