Ohio Administrative Code|Rule 3701:1-66-10 | Computed tomography radiation-generating equipment.

                                                
This rule applies to mobile and stationary computed
		tomography (CT) radiation-generating equipment, except for fluoroscopy units
		with CT capability, CT units used exclusively for radiotherapy simulation, and
		CT units integrated with linear accelerators.
(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
			 of greater than 0.5 second duration;
(2) 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;
(3) The CT x-ray control
			 and gantry shall provide visual indication whenever x-rays are
			 produced;
(4) 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. Visual 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;
(5) Each emergency button
			 or switch shall be clearly labeled as to its function;
(6) The CT
			 radiation-generating equipment shall be designed such that the CT conditions of
			 operation are indicated prior to the initiation of a scan or a scan
			 sequence;
(7) The indicated table
			 increment shall not deviate from the actual table increment by more than one
			 millimeter;
(8) Means shall be
			 provided to permit visual determination of the location of the tomographic
			 plane or a reference plane. A reference plane may be offset from the location
			 of the tomographic plane(s);
(9) If a device using a
			 light source is used to satisfy paragraph (A)(8) 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; and
(10) The total error in
			 the indicated location of the tomographic plane or reference plane shall not
			 exceed five millimeters.
(B) In addition to paragraph (G) of rule
		  3701:1-66-02 of the Administrative Code, handlers of CT radiation-generating
		  equipment shall meet the following radiation safety requirements:
(1) 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, if
			 applicable;
(2) The limits of
			 radiation dose shall not exceed a volume computed tomography dose index
			 (CTDIvol):
(a) Eighty milligray (eight rad) for the facility's
				routine adult head scan;
(b) Thirty milligray (three rad) for the facility's
				routine adult or seventy kilogram (one hundred fifty-four pound) abdomen
				scan;
(c) Twenty milligray (two rad) for the facility's
				routine pediatric five-year old or eighteen kilogram (forty pound) abdomen
				scan; and
(d) Forty milligray (four rad) for the facilitys
				routine (one-year old) pediatric head scan;
(3) If the results of the
			 quality control tests, the image quality evaluations, or the radiation dose
			 measurements exceed a tolerance limit established by a radiation expert, use of
			 the CT radiation-generating equipment on patients shall be limited to those
			 uses permitted by written instruction of a radiation expert;
(4) Mobile CT
			 radiation-generating equipment, except for stationary CT radiation-generating
			 equipment installed in a van, trailer, or mobile vehicle and operator behind a
			 protective control booth, shall be provided with protective curtains of not
			 less than 0.25 millimeter lead equivalent that completely surrounds the gantry
			 bore during exposures, unless the protective curtains interfere with the
			 sterile field of a surgical procedure; and
(5) Any individual who is
			 in the room during a CT exposure shall stand clear of the gantry bore, and
			 shall stand behind a whole body protective barrier or wear a protective lead
			 apron of not less than 0.25 millimeter lead equivalent.
(C) 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 handler shall
			 designate and utilize a radiation expert who shall:
(a) Perform measurements of the radiation dose and image
				quality prior to medical use:
(i) Upon
				  installation;
(ii) After repair or
				  replacement of any component of the CT equipment which may alter the radiation
				  output or image quality, prior to medical use, a radiation expert shall perform
				  and document measurements of radiation output, using a method specified by a
				  radiation expert in the quality assurance program, and image quality as
				  specified in paragraph (C)(1)(c) of this rule unless in the documented
				  determination of a radiation expert, the repair or replacement will not cause a
				  significant change in radiation output or significant degradation of image
				  quality as defined in the quality assurance program according to paragraph
				  (C)(1)(c) of this rule.
(a) The radiation expert
					 may designate qualified individuals to perform and document the measurements
					 specified in paragraph (C)(1)(a)(ii) of this rule;
(b) The criteria for
					 qualifying the designees specified in paragraph (C)(1)(a)(ii)(a) of this rule
					 shall be specified by a radiation expert in the quality assurance program;
					 and
(c) The radiation
					 experts approval of the designee's test results shall be documented
					 within thirty days;
(b) Perform measurements of radiation dose
				annually;
(c) Perform evaluations of image quality at least annually
				using a CT phantom which has the capability of providing an indication of CT
				number accuracy for at least three materials. The evaluation of image quality
				shall include CT number accuracy and uniformity, noise, artifacts, radiation
				beam width, resolution for low and high contrast, alignment light accuracy, and
				table travel accuracy; and
(d) . Develop the written quality control program conducted
				by the CT technologist appropriate for the evaluation of the CT system that
				includes the tests and allowable tolerance limits. The quality control
				evaluation for image quality shall include the use of a water equivalent
				phantom, and at a minimum, the evaluation of artifacts, noise, and CT number
				accuracy. The evaluation of image quality shall be at a minimum completed
				weekly;
(2) Written records of all image quality
			 evaluations and radiation dose measurements shall be maintained between
			 inspections for review by the department's inspector;
(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) In consultation with
			 a radiation expert, develop and implement a written program for radiation dose
			 optimization and scan protocol review. The protocol review must include
			 perfusion studies, if performed. The written program shall be audited by a
			 radiation expert on an annual basis;
(5) Radiation dose
			 measurements shall be performed using clinical protocols representative of the
			 utilization of the CT unit. If protocols are estimated, measurements must be
			 based on a sample of actual patient data. The specific CT conditions of
			 operation shall be documented for each protocol:
(a) Radiation dose measurements shall be expressed in terms
				of CTDIvol;
(b) 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; 
(c) 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; and
(d) Requirements of paragraphs (C)(5)(a) and (C)(5)(b) of
				this rule may be satisfied by an alternative nationally-recognized standard for
				CT dosimetry. If an alternate dosimetry method is used, a radiation expert
				shall document the procedures in the written quality assurance
				program.
(D) Cone beam computed tomography (CBCT)
		  scanners and hybrid imaging systems, with the exception of CBCT units
		  integrated with linear accelerators, shall comply with the following
		  rules:
(1) Under the guidance of
			 a radiation expert, handlers of CBCT units shall develop and implement a
			 written quality control testing program to include test procedures, test
			 frequencies, and tolerance limits;
(2) The written quality
			 control testing program must include an annual testing component to be
			 performed by a radiation expert. This annual testing component must be
			 performed upon installation of new CBCT units and annually
			 thereafter;
(3) The annual tests to
			 be performed by a radiation expert must include an assessment of radiation dose
			 and an evaluation of image quality;
(4) Records of all
			 quality control tests shall be documented and retained between
			 inspections;
(5) CBCT scanners are
			 exempt from paragraphs (B)(2) and (C)(5) of this rule; and
(6) SPECT/CT and PET/CT
			 units used exclusively for hybrid imaging shall be in compliance with paragraph
			 (B)(2) of this rule if protocols used to scan the head satisfy the limits of
			 paragraph (B)(2)(a) of this rule and protocols used to scan the abdomen satisfy
			 the limits of paragraph (B)(2)(b) of this rule.
(E) Micro-CT units equipped with an x-ray
		  tube enclosure designed to exclude personnel from its interior during x-ray
		  generation shall be exempt from paragraphs (A) to (D) of this rule, and shall
		  comply with the requirements set forth in rule 3701:1-68-06 of the
		  Administrative Code.
(F) Mobile CT radiation-generating
		  equipment permanently mounted on a base with wheels or castors for moving while
		  completely assembled and not used in one place are exempt from paragraphs
		  (H)(4) and (H)(5) of rule 3701:1-66-02 of the Administrative Code.
(G) Handlers of CT radiation-generating
		  equipment used for veterinary purposes are exempt from the requirements of
		  paragraphs (B)(2) and (C)(4) of this rule.