3701:1-66-10 Computed tomography radiation-generating equipment.

As used in this rule, "computed tomography (CT) radiation-generating equipment" means CT units used for medical diagnostic imaging as defined in paragraph (B)(9) of rule 3701:1-66-01 of the Administrative Code, except for fluoroscopy units with CT capability, tomographic therapy units, and dedicated dental CT units. In addition to other applicable rules adopted pursuant to Chapter 3748. of the Revised Code and Chapter 3701:1-66 of the Administrative Code, handlers of CT radiation-generating equipment that includes either mobile or stationary installations shall comply with the following:

(A) CT radiation-generating equipment shall be maintained to meet the following equipment standards:

(1) The operator shall be able to terminate x-ray exposure at any time during a scan, or series of scans under CT radiation-generating equipment control of greater than 0.5 second duration.

(2) The CT x-ray control and gantry shall provide visual indication whenever x-rays are produced.

(3) Each emergency button or switch shall be clearly labeled as to its function.

(4) The CT radiation-generating equipment shall be designed such that the CT imaging parameters are indicated prior to the initiation of a scan or a scan sequence.

(5) 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.

(6) The indicated table increment versus actual table increment shall comply with the manufacturer's specifications.

(7) In the case of premature termination of the x-ray exposure by the operator, the CT radiation-generating equipment shall require the operator to reset CT conditions of operation prior to the initiation of another scan.

(8) For any single tomographic system, means shall be provided to permit visual determination of the tomographic plane or a reference plane offset from the tomographic plane.

(9) For any multiple tomographic system, means shall be provided to permit visual determination of the location of a reference plane. The reference plane can be offset from the location of the tomographic planes.

(10) If a device using a light source is used to satisfy paragraph (D)(8) or (D)(9) of this rule, the light source shall provide illumination levels sufficient to permit visual determination of the location of the tomographic plane or reference plane under ambient light conditions of up to five hundred lux.

(11) The total error in the indicated location of the tomographic plane or reference plane shall not exceed five millimeters.

(B) In addition to paragraph (I) of rule 3701:1-66-02 of the Administrative Code, handlers of CT radiation-generating equipment shall meet the following facility design requirements:

(1) Windows, mirrors, closed-circuit television, or an equivalent system shall be provided to permit continuous observation of the patient during irradiation and shall be so located that the operator can observe the patient from the control panel.

(2) When the primary viewing system is by electronic means, an alternative viewing system, which may be electronic, shall be available for use in the event of failure of the primary viewing system.

(3) Provision shall be made for two-way aural communication between the patient and operator.

(C) In addition to paragraph (H) of rule 3701:1-66-02 of the Administrative Code, handlers of CT radiation-generating equipment shall meet the following radiation safety requirements:

(1) CT radiation-generating equipment which does not meet the provisions of this rule shall not be operated for diagnostic purposes.

(2) Information shall be available regarding the CT radiation-generating equipment and shall include the following:

(a) Dates of the latest radiation dose measurements and image quality evaluations and the location within the facility where the results of those tests may be obtained;

(b) Instructions on the use of the CT image quality phantom including a schedule of image quality evaluations appropriate for the system, allowable variations for the indicated parameters, and the results of at least the most recent image quality evaluations conducted on the system;

(c) The distance in millimeters between the tomographic plane and the reference plane if a reference plane is utilized; and

(d) Techniques shall be provided in the vicinity of the control panel or on a pre-programmed menu, based on patient age, weight, body mass index, or patient dimensions, as appropriate, that specifies for each routine examination the CT conditions of operation, including techniques specific to pediatric patient examinations.

(3) In consultation with the radiation expert, develop and implement a written plan, to include but not be limited to, delivering appropriate patient dose that uses ALARA principles. This plan shall be reviewed on an annual basis, not to exceed a fourteen month period.

(4) If the radiation dose measurement or image quality evaluation of the CT radiation-generating equipment identifies that a system operating parameter has exceeded a tolerance established by a radiation expert as provided in paragraph (D) of this rule, use of the CT radiation-generating equipment on patients shall be limited to those uses permitted by established written instruction of the radiation expert.

(5) Operators of CT radiation-generating equipment shall possess an Ohio radiologic license in accordance with rules in Chapter 3701-72 of the Administrative Code.

(D) In addition to other applicable quality assurance requirements in rule 3701:1-66-04 of the Administrative Code, handlers of CT radiation-generating equipment shall comply with the following quality assurance requirements:

(1) The registrant shall designate and utilize a radiation expert who shall:

(a) Perform an area radiation survey upon installation, or after any change in the CT radiation-generating equipment, its workload, or its structural shielding which may cause a significant increase in radiation hazard;

(b) Perform measurements of the radiation dose upon installation and prior to scanning patients. The measurements shall be made at least annually, not to exceed a fourteen month period, and after any change in the system which may cause a significant increase in the radiation dose.

(c) Develop written procedures to include system conditions and tolerance limits for the evaluation of image quality. The procedures shall incorporate the use of a CT phantom which has the capability of providing an indication of CT number accuracy for at least three materials, noise, tomographic section thickness, slice position, and the resolution capability of the system for low and high contrast objects.

(d) Perform evaluations of image quality according to the written procedures upon installation and prior to scanning patients and at least annually, not to exceed a fourteen month period, thereafter.

(2) Written records of all image quality evaluations shall be maintained between inspections for review by the director.

(3) The images for quality shall be retained until a new image quality evaluation is performed as follows:

(a) Photographic copies of the images obtained from the image display device; or

(b) Images stored in digital form on a storage medium compatible with the CT x-ray system.

(4) The individual responsible for radiation protection shall obtain a written report of the area radiation survey from the radiation expert, and a copy of the report shall be made available to the department's inspector upon request.

(5) The limits of radiation dose shall not exceed a volume computed tomography dose index (CTDI VOL) of:

(a) Eighty milligray (eight rad) for the facility's routine head scan;

(b) Thirty milligray (three rad) for the facility's routine adult abdomen scan; and

(c) Twenty-five milligray ( 2.5 rad) for the facility's routine five-year old pediatric abdomen scan.

(6) Compliance with the radiation dose limits shall be determined as follows:

(a) Radiation dose measurements shall be performed using the facility's routine head, routine adult abdomen, and routine five-year old pediatric abdomen scan protocol. The specific CT conditions of operation shall be documented for each protocol;

(b) Radiation dose measurements shall be expressed in terms of CTDI VOL;

(c) Radiation dose measurements shall be performed using a CT dosimetry phantom that meets the following specifications and conditions of use:

(i) The CT dosimetry phantom shall be a right circular cylinder of a material having approximate tissue equivalence of one gram per cubic centimeter. The phantom shall be at least fourteen centimeters in length and shall have diameters of thirty-two centimeters for measuring radiation dose from the adult abdomen scan protocol and sixteen centimeters for measuring radiation dose from the head and pediatric abdomen scan protocols;

(ii) The CT dosimetry phantom shall provide a means for the placement of a dosimeter along the axis of rotation and along a line parallel to the axis of rotation on the outer surface or within one centimeter from the outer surface and within the phantom. 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; and

(iv) All dose measurements shall be performed with the CT dosimetry phantom placed on the patient couch or support device without additional attenuation materials present; and

(d) Radiation dose measurements shall be performed with a calibrated dosimetry system. The calibration of such system shall be traceable to a national standard, or cross-calibrated with a dosimetry system whose calibration is traceable to a national standard. Records of these calibrations shall be readily available for review upon inspection. The dosimetry system shall have been calibrated within the preceding two years.

(7) CT radiation-generating equipment manufactured after July 31, 1974, shall have sufficient maintenance to keep it in compliance with 21 C.F.R. 1020 (as published in the April 1, 2008, Code of Federal Regulations). The handler shall maintain documentation of such maintenance between inspections.

Replaces: 3701:1-66-10

Effective: 04/15/2009
R.C. 119.032 review dates: 04/15/2014
Promulgated Under: 119.03
Statutory Authority: 3748.04
Rule Amplifies: 3748.04
Prior Effective Dates: 2/15/2001, 2/15/05