[27 Pa.B. 5703]
[Continued from previous Web Page] A person requesting that the Department approve a healing arts screening program shall submit the following information and evaluation. If information submitted to the Department becomes invalid or outdated, the registrant shall immediately notify the Department.
(1) [Name] The name and address of the applicant and, [where] if applicable, the names and addresses of agents within this Commonwealth.
* * * * * (6) An evaluation by a qualified expert of the [x-ray] X-ray systems to be used in the screening program. The evaluation [by the qualified expert] shall show that the systems [do] satisfy all requirements of this article. The evaluation shall include a measurement of patient exposures from the X-ray examinations to be performed.
* * * * * (14) This section does not apply to operations conducted by registrants under 21 CFR Part 900 (relating to mammography).
§ 221.15. Use of X-rays in research on humans.
(a) Registrants conducting research using X-rays involving human subjects are exempted from this section if the research is conducted, funded, supported or regulated by a Federal agency which has implemented the Federal policy for the protection of human subjects.
(b) A research protocol regarding the use of X-rays in research on humans shall be authorized by a committee consisting of at least three persons. One of the committee members shall be knowledgeable in radiation effects on humans.
(c) All proposed subjects or their legal representative shall sign a statement acknowledging that they have been informed of their anticipated radiation exposure and possible consequences arising from this exposure.
(d) A person requesting that the Department approve a program using X-rays for research on humans shall submit, in writing, the following information and evaluation to the Department. If information submitted to the Department becomes invalid or outdated, the registrant shall immediately notify, in writing, the Department.
(1) The name and address of the applicant and, if applicable, the names and addresses of agents within this Commonwealth.
(2) A description of the population to be examined in the research program, age, sex, physical condition and other appropriate information.
(3) An evaluation of known alternate methods not involving ionizing radiation which could achieve the goals of the research program and why these methods are not used in preference to the X-ray examinations.
(4) An evaluation by a qualified expert of the X-ray system to be used in the research program. This evaluation shall show that the system satisfies the requirements of this article. The evaluation shall include a projected measurement of individual and cumulative patient exposures from the X-ray examinations to be performed.
(5) A description of the diagnostic X-ray quality control program.
(6) A copy of the chart which specifies the information for the X-ray examination procedures to be used.
(7) The qualifications of all individuals who will be operating the X-ray system.
(8) The qualifications of the physician who will be supervising the operators of the x-ray systems. The extent of supervision and the method of work performance evaluation shall be specified.
(9) The name and address of the individual who will interpret the radiographs.
(10) A copy of the research protocol authorized by the committee established under subsection (b).
DIAGNOSTIC INSTALLATIONS GENERAL REQUIREMENTS § 221.21. Diagnostic equipment requirements.
[Diagnostic x-ray equipment and its use shall satisfy the applicable requirements of Subchapter A.] Diagnostic systems incorporating one or more certified components shall comply with 21 CFR 1020.30[, 1020.31 and 1020.32 (relating to diagnostic x-ray systems and their major components; radiographic equipment; and fluoroscopic equipment)]--1020.33.
§ 221.28. Technique indicators.
(a) The technique factors for radiographic systems shall be indicated before exposure except for units utilizing automatic exposure controls, in which case the [preset factors may] maximum mAs shall be indicated.
(b) The requirement of subsection (a) may be met by permanent markings on equipment having fixed technique factors. Indication of technique factors shall be visible from the operator's position except in the case of spot films made by a fluoroscopist.
§ 221.29. Kilovoltage accuracy.
Discrepancies of more than 10% between set--indicated--and measured kV values shall be investigated by a qualified expert or service engineer and appropriate action taken.
§ 221.30. Exposure reproducibility.
The coefficient of variation of exposure reproducibility may not exceed 0.10 when technique factors are held constant. This requirement shall be deemed to have been met when four exposures are made. This requirement applies when either manual techniques or automatic exposure control is used.
(Editor's Note: As part of this proposal, the Board is proposing to delete the existing text of §§ 221.31-- 221.49, 221.51--221.56, 221.61, 221.62, 221.71--221.76 and 221.81--221.102, which appears at 25 Pa. Code pages 221-30--221-58, serial pages (123698)--(123726).)
§§ 221.31--221.49. (Reserved.)
§§ 221.51--221.56. (Reserved.)
§ 221.61. (Reserved.)
§ 221.62. (Reserved.)
§§ 221.71--221.76. (Reserved.)
§§ 221.81--221.102. (Reserved.)
§ 221.31a. Locks.
All position locking, holding and centering devices on X-ray systems shall function as intended.
§ 221.32a. A beam limitation.
(a) The useful beam shall be limited to the area of clinical interest.
(b) The beam limiting device shall do one of the following:
(1) Indicate numerically the field size in the plane of the image receptor to which it is adjusted to within 2% of the SID.
(2) Provide for visually defining the perimeter of the X-ray field except for systems designed for one image receptor size. The total misalignment of the edges of the visually defined field with the respective edges of the X-ray field may not exceed 2% 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) A means shall be provided for stepless (continuous) adjustment of the size of the X-ray field except for systems which use removable fixed operation beam limiting devices.
(d) A means shall be provided to:
(1) Indicate when the axis of the X-ray beam is perpendicular to the plane of the image receptor.
(2) Align the center of the X-ray field with respect to the center of the image receptor to within 2% of the SID.
(3) Indicate the SID to within 2%.
(e) X-ray systems designed for use with an intraoral image receptor shall be provided with means to limit SSD to not less than either of the following:
(1) Eighteen centimeters if operable above 50 kVp.
(2) Ten centimeters if not operable above 50 kVp.
(f) Indication of field size dimensions and SIDS shall be specified so 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% of the SID when the beam axis is indicated to be perpendicular to the plane of the image receptor.
(g) Radiographic systems designed for use with an intraoral image receptor shall be provided with a means to limit the X-ray beam so that if the minimum SSD is:
(1) Eighteen centimeters or more, the X-ray field at the minimum SSD shall be containable in a circle having a diameter of no more than 7 centimeters.
(2) Less than 18 centimeters, the X-ray field at the minimum SSD shall be containable in a circle having a diameter of no more than 6 centimeters.
(h) When positive beam limitation is used, the following conditions shall be met:
(1) The radiation beam may not be larger than the size of the image receptor being used.
(2) The positive beam limitation device shall allow the operator to further reduce the size of the radiation field.
(i) Mobile or portable radiographic systems shall be provided with a means to limit the source-to-skin distance to at least 30 centimeters.
(j) Radiographic equipment designed for one or more image receptor sizes at a fixed SID shall be provided with a means to accomplish one of the following:
(1) Limit the field at the plane of the image receptor to dimensions no greater than those of the image receptor and align the center of the X-ray field with the center of the image receptor to within 2% of the SID.
(2) The X-ray field shall be sized and aligned so that at the plane of the image receptor, it does not extend beyond the edge of the image receptor by more than 2% of the SID.
§ 221.33a. Radiation from capacitor energy storage equipment in standby status.
Radiation emitted from an X-ray tube when the exposure switch or timer is not activated may not exceed a rate of 2 milliroentgens (0.516 µC/kg) per hour at 5 centimeters from an accessible surface of the diagnostic source assembly, with the beam-limiting device fully open.
§ 221.34a. Radiation exposure control.
(a) Radiation exposure control. Radiation exposure shall be possible only through intentional switch actuation by the operator. The radiation exposure control switch and associated circuitry shall preclude unintended actuation not initiated by the operator.
(b) Visual indication and audible signal. A means shall be provided for visual indication observable from the operator's protected position whenever X-rays are produced. In addition, a signal audible to the operator shall indicate that the exposure has terminated.
(c) Termination of exposure. A means shall be provided to terminate the exposure at a preset time interval, preset product of current and time, a preset number of pulses or a preset radiation exposure to the image receptor. Except for dental panoramic systems, termination of an exposure shall cause automatic resetting of the time to its initial setting or to ''zero.''
(d) Manual exposure control. An X-ray control shall be incorporated into each X-ray system which allows the operator to terminate an exposure at any time except for one or more of the following:
(1) Exposure of 1/2 second or less.
(2) During serial radiography in which cases means shall be provided to permit completion of any single exposure of the series in process.
(e) Automatic exposure control.
(1) Indication shall be made on the control panel when this mode of operation is selected.
(i) A means shall be provided to terminate irradiation at an appropriate exposure for the projection if the automatic exposure control fails to terminate irradiation.
(ii) A visible signal shall indicate when an exposure has been terminated at the limits required by subparagraph (i), and manual resetting shall be required before further automatically timed exposures can be made.
(2) For X-ray systems operating in automatic exposure control mode, and which lack engineered safeguards that prevent exposure in the event of either a malfunction or a mispositioned X-ray beam with respect to film cassette sensors, the back-up or default mAs shall be set by the operator to an appropriate maximum value for the projection.
(3) X-ray systems utilizing automatic exposure control, in which the back-up mAs values are preset and cannot be selected by the operator, shall prominently indicate the preset mAs value on the console, along with an appropriate warning notice to the operator.
(f) Exposure control location
(1) Stationary X-ray systems shall have X-ray controls permanently mounted in a protected area and situated so that the operator is required to remain in that protected area during the entire exposure.
(2) For mobile and portable X-ray systems the exposure switch shall be arranged so that the operator can stand at least 2 meters from the patient and from the tube head and away from the direction of the useful X-ray beam.
FLUOROSCOPIC X-RAY SYSTEMS § 221.35a. Fluoroscopic X-ray systems.
Fluoroscopic X-ray systems shall use an image intensifier and in addition to the requirements of §§ 221.1--221.34a, shall meet the requirements of §§ 221.36a--221.38a (relating to limitation of useful beam of fluoroscopic equipment; activation of fluoroscopic tube; and entrance exposure rate).
§ 221.36a. Limitation of useful beam of fluoroscopic equipment.
(a) The fluoroscopic imaging assembly shall be provided with a primary protective barrier which intercepts the entire cross section of the useful beam at any source-to-image receptor distance.
(b) The X-ray tube used for fluoroscopy may not produce X-rays unless a barrier is in position to intercept the useful beam and the imaging device is in place and operable.
(c) A means shall be provided for stepless (continuous) adjustment of the field size.
(d) The minimum field size at the greatest source to image receptor distance shall be equal to or less than 25 square centimeters.
(e) Equipment may not be operated at a source to skin distance less than 30 centimeters or as required under 21 CFR 1020.32 (relating to fluoroscopic equipment).
(f) The width of the X-ray field in the plane of the image receptor may not exceed that of the visible area of the image receptor by more than 3% of the source to image receptor distance. The sum of the excess length and the excess width may not be greater than 4% of the source to image receptor distance.
(g) For rectangular X-ray fields used with a circular image receptor, the error in alignment shall be determined along the length and width dimensions of the X-ray field which passes through the center of the visible area of the image receptor.
(h) Compliance with subsections (a)--(g) shall be determined with the beam axis perpendicular to the plane of the image receptor.
(i) Spot-film devices shall meet the following additional requirements:
(1) A means shall be provided between the source and the patient for adjustment of the X-ray field size to the size of the portion of film which has been selected on the spot-film selector.
(2) The adjustments shall be automatically accomplished except when the X-ray field size in the plane of the film is smaller than that of the film.
(3) The total misalignment of the edges of the X-ray field with the respective edges of the selected portion of the image receptor along the length or width dimensions of the X-ray field in the plane of the image receptor may not exceed 3% of the source-to image receptor when adjusted for full coverage of the selected portion of the image receptor.
(4) The sum, without regard to sign, of the misalignment along any 2 orthogonal dimensions, may not exceed 4% of the source to image receptor distance.
(j) The center of the X-ray field in the plane of the film shall be aligned with the center of the film within 2% of the source to image receptor distance.
§ 221.37a. Activation of fluoroscopic tube.
X-ray production in the fluoroscopic mode shall be controlled by a device which requires continuous pressure by the fluoroscopist for the entire time of the exposure (dead-man switch). When recording serial fluoroscopic images, the fluoroscopist shall be able to terminate X-ray exposures at any time, but means may be provided to permit completion of any single exposure of the series in process.
§ 221.38a. Entrance exposure rate.
(a) Fluoroscopic systems without high level control. The exposure rate may not exceed 10 roentgens (2.58 mC/kg) per minute except during recording of fluoroscopic images.
(b) Fluoroscopic systems with high level control.
(1) When the high level control is activated, the maximum exposure rate shall be 20 roentgens (5.16 mC/kg) per minute.
(2) When the high level control is not activated, the maximum exposure rate shall be 10 roentgens (2.58 mC/kg) per minute.
(3) Special means of activation of high level controls are required. The high level control shall only be operable when continuous manual activation is provided by the operator.
(4) There shall be an indication to the fluoroscopist that the high level control is being used.
(c) Frequency of output measurements. Output measurements required by this section shall be made annually and after maintenance that could affect the output of the machine.
(d) Compliance requirements. Compliance with subsections (a)--(c) shall be determined as follows:
(1) If the source is below the table, the exposure rate shall be expressed for the center of the useful beam 1 centimeter above the tabletop or cradle with the image intensifier 30 centimeters above the tabletop or cradle.
(2) If the source is above the table, the exposure rate shall be measured at 30 centimeters above the tabletop with the end of the beam-limiting device or spacer positioned as closely as possible to the point of measurement.
(3) In a c-arm type of fluoroscope, the exposure rate shall be measured at 30 centimeters from the input surface of the fluoroscopic imaging assembly with the source at its closest possible position of operation.
(4) The tube potential and current shall be set to give the maximum exposure possible from the X-ray system. For systems with automatic exposure control, at least 3 millimeters of lead shall be placed between the measuring device and image receptor.
(5) The measurement shall be made at the center of the useful beam.
§ 221.39a. Barrier transmitted radiation rate limits.
The protective barrier may not transmit more than 2 milliroentgens (.516 µmC/kg) per hour at 10 centimeters from an accessible surface of the fluoroscopic imaging assembly for each roentgen per minute of entrance exposure rate.
§ 221.40a. Indication of tube voltage and current.
During fluoroscopy and cinefluorography, the voltage and the current shall be continuously indicated.
§ 221.41a. Source-skin distance.
The source to skin distance may not be less than 30 centimeters.
§ 221.42a. Fluoroscopic timer.
A cumulative timing device activated by the fluoroscope switch shall be provided. It shall indicate the passage of a predetermined period of irradiation either by an audible signal or by temporary or permanent interruption of the irradiation when the increment of exposure time exceeds a predetermined limit not exceeding 5 minutes.
§ 221.43a. Control of scattered radiation.
(a) Fluoroscopic table designs when combined with normal operating procedures shall be of a type so no unprotected part of the staff or an ancillary individual's whole body is exposed to unattenuated scattered radiation which originates from under the table. The attenuation required may be not less than .25 millimeter lead equivalent.
(b) Equipment configuration when combined with normal operating procedures shall be of a type so no portion of the staff or an ancillary individual's whole body, except the extremities, is exposed to the unattenuated scattered radiation emanating from above the table top unless one of the following criteria is met:
(1) The individual is at least 120 centimeters from the center of the useful beam.
(2) The radiation has passed through not less than .25 millimeter lead equivalent material--for example, drapes, Bucky-slot cover, sliding or folding panel or self supporting curtains--in addition to lead equivalency provided by the protective apron referred to in § 221.11(e) (relating to registrant responsibilities).
§ 221.44a. Mobile fluoroscopes.
In addition to the other requirements of §§ 221.35a--221.43a, mobile fluoroscopes shall provide image intensification.
(Editor's Note: Sections 221.201--221.205 are new. They have been printed in regular type to enhance readability.)
COMPUTED TOMOGRAPHY X-RAY SYSTEMS § 221.201. Definitions.
In addition to the definitions in §§ 215.2 and 221.2 (relating to definitions), the following words and terms when used in this section and §§ 221.202--221.205 (relating to computed tomography 2-ray systems), have the following meanings, unless the context clearly indicates otherwise:
CS--Contrast scale--The change in the linear attenuation coefficient per CT number relative to water; that is:
CS = (Ux-Uw)/((CT)x-(CT)w)
Where:
Ux = Linear attenuation coefficient of the material of interest
Uw = Linear attenuation coefficient of water
(CT)x = CT number of the material of interest
(CT)w = CT number of water
CT--Computed tomography--The production of a tomogram by the acquisition and computer processing of X-ray transmission data.
CTDI--Computed tomography dose index--The integral of the dose profile along a line perpendicular to the tomographic plane divided by the product of the nominal tomographic section thickness and the number of tomograms produced in a single scan.
CT conditions of operation--The selectable parameters governing the operation of a CT X-ray system including, but not limited to, nominal tomographic section thickness, filtration and the technique factors as defined in this chapter.
CT number--The number used to represent the X-ray attenuation associated with each elemental area of the CT image.
Elemental area--The smallest area within a tomogram for which the X-ray attenuation properties of a body are depicted.
Gantry--The tube housing assemblies, beam-limiting devices, detectors, transformers, if applicable, and the supporting structures and frames which hold these components.
Lux--A unit illumination equivalent to 1 lumen per square centimeter or .0929 foot-candles.
MSAD--Multiple scan average dose--The calculated average dose to the tissue within each slice in a seriesutilizing an ion chamber. The MSAD is calculated using the following equation:
MSAD = (F × K × L × E) / (T × N)
Where
F = Factor to convert exposure in air to absorbed dose in lucite in RADS/mR
K = Calibration factor to account for the ion chamber's response and volume.
L = Effective length of ion chamber in millimeters (mm)
E = Exposure reading in milliroentgen (mR)
T = Nominal slice thickness in millimeters (mm) and
N = Number of slices per scan
Multiple tomogram system--A computed tomography X-ray system which obtains X-ray transmission data simultaneously during a single scan to produce more than one tomogram.
Noise--The standard deviation of the fluctuations in the CT number expressed as a percentage of the attenuation coefficient of water. Its estimate (Sn) is calculated using the following expression:
Sn = 100 × CS × S/Uw
Where:
CS = Contrast scale
Uw = Linear attenuation coefficient of water.
S = estimated standard deviation of the CT number of picture elements in a specified area of the CT image.
Nominal tomographic section thickness--The full-width at half-maximum of the sensitivity profile taken at the center of the cross-sectional volume over which X-ray transmission data are collected.
Performance phantom--A phantom which has a capability of providing an indication of contrast scale, noise, nominal tomographic section thickness, the resolution capability of the CT system for low and high contrast objects, and measuring the mean CT number for water or other reference materials.
Picture element--See elemental area.
Pixel--See elemental area.
Reference plane--A plane which is at a known fixed distance--which could be zero--to the tomographic plane and parallel to it.
Scan--The complete process of collecting X-ray transmission data for the production of a tomogram. Data may be collected simultaneously during a single scan for the production of one or more tomograms.
Scan increment--The amount of relative displacement of the patient with respect to the CT X-ray system between successive scans measured along the direction of the displacement.
Scan sequence--A preselected set of two or more scans performed consecutively under preselected CT conditions of operation.
Scan time--The period of time between the beginning and end of X-ray transmission data accumulation for a single scan.
Sensitivity profile--The relative response of the CT X-ray system as a function of position along a line perpendicular to the tomographic plane.
Single tomogram system--A CT X-ray system which obtains X-ray transmission data during a scan to produce a single tomogram.
Technique factors--The conditions of operation, specified as follows:
(i) For CT equipment designed for pulsed operations, peak tube potential, scan time in seconds, X-ray pulse width in seconds, and the number of X-ray pulses per second or per mAs.
(ii) For CT equipment not designed for pulsed operation, peak tube potential, and either tube current and scan time in seconds or the product of tube current and exposure time in mAs.
Tomogram--The depiction of the X-ray attenuation properties of a section through a body.
Tomographic plane--The geometric plane which is identified as corresponding to the output tomogram.
Tomographic section--The volume of an object whose X-ray attenuation properties are imaged in a tomogram.
§ 221.202. Equipment requirements
(a) Termination of exposure. The operator shall be able to terminate the X-ray exposure at any time during a scan, or series of scans under X-ray system control, of greater than 0.5 second duration. Termination of the X-ray exposure shall necessitate resetting of the conditions of operation prior to initiation of another scan.
(b) Tomographic plane indication and alignment.
(1) For any single tomogram system, a means shall be provided to permit visual determination of the tomographic plane or a reference plane offset from the tomographic plane.
(2) For any multiple tomogram system, a means shall be provided to permit visual determination of the location of a reference plane. This reference plane may be offset from the location of the tomographic plane.
(c) Status indicators and control switches.
(1) The CT X-ray control and gantry shall provide visual indication whenever X-rays are produced and, if applicable, whether the shutter is open or closed.
(2) A signal, audible to the operator, shall indicate that the exposure has terminated.
(3) The emergency buttons or switches shall be clearly labeled as to their function.
(4) Each individual scan or series of scans shall require initiation by the operator.
(d) Indication of CT conditions of operation. The CT X-ray system shall be designed so that the CT conditions of operation to be used during a scan or a scan sequence are indicated prior to the initiation of a scan or a scan sequence. On equipment having all or some of these conditions of operation at fixed values, this requirement may be met by permanent markings. Indication of CT conditions of operation shall be visible from any position from which scan initiation is possible.
(e) Leakage radiation. The leakage radiation from the diagnostic source assembly measured at a distance of 1 meter in any direction from the source may not exceed 100 milliroentgens (25.8 µC/kg) in 1 hour when the X-ray tube is operated at its leakage technique factors. Compliance shall be determined by measurements averaged over an area of 100 square centimeters with no linear dimension greater than 20 centimeters.
(f) Beam quality. The total filtration (inherent plus added) shall be at least 3.5 millimeters aluminum equivalent. This requirement will be considered to have been met if it can be demonstrated that the half value layer of the primary beam is not less than 4.60 millimeters of aluminum equivalent at 120 kVp.
(g) Additional requirements applicable to CT X-ray systems containing a gantry manufactured after September 3, 1985.
(1) The total error in the indicated location of the tomographic plane or reference plane by the light field or laser indicator may not exceed 3 millimeters.
(2) If the X-ray production period is less than 0.5 second, the indication of X-ray production shall be actuated for at least 0.5 second. Indicators at or near the gantry shall be discernible from any point external to the patient opening where insertion of any part of the human body into the primary beam is possible.
(3) The CT X-ray system shall be normalized to water.
(4) The CT number for water for a region of interest not exceeding 100 square millimeters shall be 0 ± 10.0 CT number units. The facility's performance phantom shall be utilized, with the technique factors specified by the qualified expert, to confirm compliance.
(5) With the performance phantom, the mean CT number of water of one group of pixels may not differ from the mean CT number of water of a second group of pixels equal size within the same image by more than the manufacturer's published specifications.
(6) The noise, utilizing the facility's performance phantom, may not exceed the manufacturer's published specifications.
(7) The total error in the indicated slice thickness may not exceed 2.0 millimeters.
(8) A distance of at least 100 millimeters measured in a CT image shall agree with the actual distance to within ± 5%.
(9) Premature termination of the X-ray exposure by the operator shall necessitate resetting the CT conditions of operation prior to the initiation of another scan.
§ 221.203. Facility design requirements.
(a) Oral communication. Provision shall be made for oral communication between the patient and the operator at the control panel.
(b) Viewing systems.
(1) A means shall be provided to permit continuous observation of the patient during irradiation and shall be located so that the operator can observe the patient from the control panel.
(2) If the primary viewing system is by electronic means, an alternate viewing system, which may be electronic, shall be available for use in the event of failure of the primary viewing system.
§ 221.204. Radiation measurements and performance evaluations.
(a) Radiation measurements.
(1) The CTDI or MSAD along the two axes specified in subsection (b)(2)(ii) shall be measured. The CT dosimetry phantom shall be oriented so that the measurement point 1.0 centimeter from the outer surface and within the phantom is in the same angular position within the gantry as the point of maximum surface exposure identified. The CT conditions of operation shall be reproducible and correspond to typical values used by the registrant.
(2) CT dosimetry phantoms shall be used in determining the radiation output of a CT X-ray system. The phantoms shall meet the definition for a CT dosimetry phantom under 21 CFR 1020.33(b)(6) (relating to computed tomography (CT) equipment).
(i) The phantoms shall be specifically designed for CT dosimetry and deemed appropriate by the facility's qualified expert and the Department.
(ii) CT dosimetry phantoms shall provide a means for the placement of dosimeters along the axis of rotation and along a line parallel to the axis of rotation 1.0 centimeter from the outer surface and within the phantom. The means for the placement of dosimeters or alignment devices at other locations may be provided.
(iii) Any effects on the doses measured due to the removal of phantom material to accommodate dosimeters shall be accounted for through appropriate corrections to the reported data or included in the statement of maximum deviation for the values obtained using the phantom.
(iv) Dose measurements shall be performed with the CT dosimetry phantom placed on the patient couch or support device without additional attenuation materials present.
(3) In addition to the items in subsection (b), the following items shall be evaluated during an interval not exceeding 12 months or after any major component repair or change which in the opinion of the qualified expert may effect the performance of the CT unit:
(i) HVL (half value layer) determination at the most commonly used kVp.
(ii) CTDI or MSAD as specified in § 221.201 (relating to definitions) for commonly used techniques.
(iii) Tomographic plane indication (light/laser alignment).
(iv) Slice thickness as specified in § 221.202(g)(7) (relating to equipment requirements).
(v) Distance readout calibration.
(4) The measurement of the radiation output of a CT X-ray system shall be performed with a dosimetry system that has calibration traceable to National Institute of Standards and Technology. The calibration of the system shall be in accordance with an established calibration protocol. The calibration protocol published by the AAPM is accepted as an established protocol. Other protocols which are equivalent will be accepted, but the user shall submit that protocol to the Department for concurrence that the protocol is equivalent.
(5) An mR/mAs value shall be determined at least annually for the head and body.
(6) Procedures and results shall be maintained for 5 years and be available for review by the Department.
(b) Peformance evaluations.
(1) Written performance evaluation procedures shall be developed by a qualified expert. These procedures shall be available for review by the Department.
(2) The performance evaluation procedures shall include at least the following using the facility's performance phantom:
(i) Noise.
(ii) Contrast scale.
(iii) Spatial resolution (low and high contrast).
(iv) Mean CT number for water.
(v) Acceptable tolerances.
(3) The performance evaluation shall be performed at intervals not to exceed 3 months by the qualified expert or an individual designated by the qualified expert.
(4) The qualified expert need not be present during the performance evaluation, but shall be informed within 15 days of any problems or unacceptable deviations.
(5) Performance evaluations shall include acquisition of images obtained with the performance phantom using the same processing mode and CT conditions of operation as are used to perform the measurements required by subsection (a).
(6) Records of the performance evaluations shall be maintained for inspection by the Department for at least 5 years.
§ 221.205. Operating procedures.
(a) Information shall be available at the control panel regarding the operation and performance evaluations of the system. The information shall include the following:
(1) The dates of the latest radiation measurements and performance evaluation and the location within the facility where the results of those tests may be obtained.
(2) Instructions on the use of the CT phantoms including a schedule of performance evaluations appropriate for the system, allowable variations for the indicated parameters and the results of at least the most recent performance evaluation conducted on the system.
(3) The distance in millimeters between the tomographic plane and the reference plane if the reference plane is utilized.
(4) A current technique chart available at the control panel which specifies for each routine examination the CT conditions of operation and the number of scans per examination.
(b) If the radiation measurements and performance evaluation of the CT X-ray system indicates that a system operating parameter has exceeded a tolerance established by the qualified expert, use of the CT X-ray system on patients shall be limited to those uses permitted by established written instructions of the qualified expert.
APPENDIX A
DETERMINATION OF COMPETENCE The following are areas in which an individual shall have expertise for the competent operation of diagnostic X-ray equipment:
(1) Familiarization with equipment.
(1) Identification of controls.
(2) Function of each control.
(3) How to use a technique chart.
(2) Radiation protection.
(i) Collimation.
(ii) Filtration.
(iii) Gonad shielding and other patient protection devices if used.
(iv) Restriction of X-ray tube radiation to image receptor.
(v) Personnel protection.
(vi) Grids.
(vii) Proper use of personnel dosimetry, if required.
(viii) Understanding units of radiation.
(3) Film processing.
(i) Film speed as related to patient exposure.
(ii) Film processing parameters.
(iii) Quality assurance program.
(iv) Identification of film artifacts and corrective actions, if necessary.
(v) Identification of adequate film exposure on the resultant radiograph, and corrective actions, if necessary.
(4) Procedures.
(i) Knowledge of anatomy and physiology.
(ii) Knowledge of positioning and radiographic demonstration of the requested anatomy with corrective actions, if necessary.
(5) Emergency procedures. Termination of exposure in event of automatic timing device failure.
(6) Continuing education. Continuing education annually to include radiation protection.
(Editor's Note: Sections 223.7 and 223.8 are new. They have been printed in regular type to enhance readability.)
CHAPTER 223. VETERINARY MEDICINE
GENERAL PROVISIONS § 223.7. Structural shielding.
Facilities regularly used for diagnostic or therapeutic veterinary X-ray procedures shall have protective barriers sufficient to assure compliance with § 219.51 (relating to radiation dose limits for individual members of the public).
§ 223.8. Operating procedures.
(a) Individuals, whose presence is not necessary to conduct the X-ray procedures, shall be located in a shielded area or at least 5 meters from the primary X-ray beam and X-ray tubehead.
(b) Mechanical supporting or restraining devices shall be used during X-ray procedures to hold the animal patient or films in position, when the technique permits.
(c) All individuals whose presence is necessary to conduct X-ray procedures and who are not located behind protective barriers or at least 5 meters from the X-ray tubehead and primary X-ray beam shall be protected with appropriate shielding devices such as lead aprons and gloves, and be positioned so that no part of their body except hands and forearms will be exposed to the primary beam. Appropriate shielding devices shall have a lead equivalent at least 0.5 millimeters of lead.
(d) All X-ray exposures shall be ordered by a veterinarian.
[X-RAYS] X-RAY EQUIPMENT § 223.11. [Equipment] Radiographic equipment.
(a) Leakage radiation.
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