Fluke Biomedical 76-414 - Manual (Page 11)

Operation
§1020.33 Computed Tomography (CT) Equipment
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3) Imaging Performance Information . The following performance data shall be provided for the CT
conditions of operation used to provide the information required by paragraph (c)(2)(i) of this section.
All other aspects of data collection, including the x-ray attenuation properties of the material in the
tomographic section, shall be similar to those used to provide the dose information required by
paragraph (c)(2)(i) of this section. For any CT x-ray system designed to image both the head and
body, separate imaging performance information shall be provided for each application.
(i) A statement of the noise.
(ii) A graphical presentation of the modulation transfer function for the same image processing and
display mode as that used in the statement of the noise.
(iii) A statement of the nominal tomographic section thickness(es).
(iv) A graphical presentation of the sensitivity profile, at the location corresponding to the center
location of the dosimetry phantom, for each selectable nominal tomographic section thickness for
which the dose profile is given according to paragraph (c)(2)(iv) of this section.
(v) A description of the phantom or device and test protocol or procedure used to determine the
specifications and a statement of the maximum deviation from the specifications provided in
accordance with paragraphs (c)(3)(i),(ii),(iii), and (iv) of this section. Deviation of actual values
may not exceed these limits.
D. Quality Assurance
The manufacturer of any CT x-ray system shall provide the following with each system. All information required
by this subsection shall be provided in a separate section of the user's instructional manual.
1) A phantom(s) capable of providing an indication of contrast scale, noise, nominal tomographic
section thickness, the spatial resolution capability of the system for low and high contrast objects,
and measuring the mean CT number of water or a reference material.
2) Instructions on the use of the phantom(s) including a schedule of testing appropriate for the system,
allowable variations for the indicated parameters, and a method to store as records, quality
assurance data.
3) Representative images obtained with the phantom(s) using the same processing mode and CT
conditions of operation as in paragraph (c)(3) of this section for a properly functioning system of the
same model. The representative images shall be of two forms as follows:
(i) Photographic copies of the images obtained from the image display device
(ii) Images stored in digital form on a storage medium compatible with the CT x-ray system. The
CT x-ray system shall be provided with the means to display these images on the image display
device.
E. [Reserved]
F. Control and Indication of Conditions of Operation
1) The CT conditions of operation to be used during a scan or a scan sequence shall be indicated
prior to 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 the CT conditions of operation shall be visible from any position from which scan
initiation is possible.
2) Timers , (i) Means shall be provided to terminate the x-ray exposure automatically by either de-
energizing the x-ray source or shuttering the x-ray beam in the event of equipment failure affecting
data collection. Such termination shall occur within an interval that limits the total scan time to no