Current through Register Vol. 47, No. 52, December 29, 2023
a) Requirements for Equipment
1) Termination of Exposure
A) In the event of equipment failure
affecting data collection, means shall be provided to terminate the x-ray
exposure automatically, either by de-energizing the x-ray source or by
shuttering the x-ray beam, through the use of either a back-up timer or devices
that monitor equipment function.
B)
A visible signal shall indicate when the x-ray exposure has been terminated
through the means required by subsection (a)(1)(A).
C) The operator shall be able to terminate
the x-ray exposure at any time during a scan, or series of scans, of greater
than 0.5 second duration.
2) Tomographic Plane Indication and Alignment
A) Means shall be provided to permit visual
determination of the location of a reference plane. This reference plane can be
offset from the location of the tomographic planes.
B) If a device using a light source is used
to satisfy subsection (a)(2)(A), 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
500 lux (45 footcandles).
C) The
total error in the indicated location of the tomographic plane or reference
plane shall not exceed 5 millimeters.
D) The deviation of indicated scan increment
versus actual increment shall not exceed plus or minus 1 millimeter with a
typical patient mass resting on the patient support device. The patient support
device shall be moved incrementally from a typical starting position to the
maximum incremental distance or 30 centimeters, whichever is less, and then
returned to the starting position. If the CT system has the capability of
variable gantry angles, the compliance measurements shall be performed with the
CT gantry positioned at zero degrees.
3) Beam-On and Shutter Status Indicators. The
CT x-ray control panel and gantry shall provide visual indication whenever
x-rays are produced and, if applicable, whether the shutter is open or
closed.
4) Technique Indicators.
The CT x-ray control panel shall provide visual indication of the technique
factors, tomographic section thickness and scan increment prior to the
initiation of a scan or a series of scans.
b) Facility Design Requirements
1) The control panel shall be located behind
a protective barrier.
2)
Communication. Provision shall be made for two-way aural communication between
the patient and the operator at the control panel.
3) Viewing Systems. Windows, mirrors,
closed-circuit television or an equivalent system 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.
c) Radiation dose measurements
shall be performed by a diagnostic imaging specialist on each CT x-ray system.
The measurements shall be specified in terms of the computed tomography dose
index (CTDI), for the head and abdomen, using a head or abdomen phantom,
respectively, and the facility's technique factors most frequently used for a
CT examination of the head or abdomen, respectively, and shall be performed:
1) At least annually by a diagnostic imaging
specialist and after any change or replacement of components that could cause a
change in the radiation output;
2)
With a dosimetry system that has been calibrated within the preceding 12
months. The calibration of such system shall have no more than a three-step
(tertiary) calibration, traceable to the National Institute of Standards and
Technology; and
3) Using the
computed tomography dose measurement protocol found in Report 111 of the
American Association of Physicists in Medicine (AAPM), entitled "Comprehensive
Methodology for the Evaluation of Radiation Dose in X-Ray Computed Tomography"
published by AAPM, February 2010, exclusive of subsequent amendments or
editions. A copy of this report is available for public inspection at the
Illinois Emergency Management Agency, 1035 Outer Park Drive, Springfield,
Illinois or may also be obtained directly from the AAPM, One Physics Ellipse,
College Park MD 20740-3846.
AGENCY NOTE: The Agency recognizes that other phantoms and
protocols are available to provide accurate dose measurements as specified in
this Section. The Agency will consider use of such phantoms and protocols as
satisfying this Section if the intent of the regulation is met.
d) Diagnostic Imaging
Specialists who perform radiation dose measurements and develop quality
assurance procedures for CT systems shall have CT training as follows:
1) Individuals certified in diagnostic
radiological physics or radiological physics by either the American Board of
Radiology or the American Board of Medical Physics shall have 20 contact hours
of documented specialized training in conducting surveys of CT
equipment;
2) Individuals not
certified as specified in subsection (d)(1) shall have 40 contact hours of
documented specialized training in conducting surveys of CT
equipment.
e)
Documentation of the training required by subsection (d) shall be available for
review at the facility by January 1, 2015. Documentation shall include the name
of the individual performing the CT training.
f) Quality assurance procedures shall be
conducted on each CT system and shall meet the following requirements:
1) The quality assurance procedures shall be
in writing and shall have been developed by a diagnostic imaging specialist.
The procedures shall include, but need not be limited to, the following:
A) Specifications of the tests that are to be
performed, including instructions to be employed in the performance of those
tests; and
B) Specifications of the
frequency at which tests are to be performed, the acceptable tolerance for each
parameter measured and actions to be taken if tolerances are
exceeded.
2) Quality
assurance procedures shall include acquisition of images using a CT phantom
that has the capability of providing an indication of the resolution capability
of the system. Quality assurance procedures shall include, at a minimum:
A) Image quality evaluation, including CT
number uniformity, noise, and low and high contrast resolution;
B) Quantitative accuracy including CT number
calibration and constancy;
C) Image
display evaluation, including visual and hard copy output.
g) Operating Procedures.
Information shall be available at the control panel regarding the operation of
the system. The information shall include written quality assurance procedures,
as required in subsection (f)(1).
Amended at
38
Ill. Reg. 12031, effective
5/29/2014
