Current through all regulations passed and filed through March 18, 2024
This ruleapplies 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 preprogrammed 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
facility's 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 expert's 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.