Fluke Biomedical 76-414 - Manual (Page 9)

Operation
§1020.33 Computed Tomography (CT) Equipment
2
2-3
Where:
CS = Contrast scale.
μ
w
= Linear attenuation coefficient of water.
s = Estimated standard deviation of the CT numbers of picture elements in a specified area of the
CT image.
11) Nominal Tomographic Section Thickness Means
The full-width at half-maximum of the sensitivity profile taken at the center of the cross-sectional
volume over which x-ray transmission data are collected.
12) Picture Element Means
An elemental area of a tomogram.
13) Remanufacturing Means
Modifying a CT system in such a way that the resulting dose and imaging performance become
substantially equivalent to any CT x-ray system manufactured by the original manufacturer on or
after November 29, 1984. Any reference in this section to "manufacture", "manufacturer", or
"manufacturing" includes remanufacture, remanufacturer, or remanufacturing, respectively.
14) Scan Increment Means
The amount of relative displacement of the patient with respect to the CT x-ray system between
successive scans measured along the direction of such displacement.
15) Scan Sequence Means
A preselected set of -two or more scans performed consecutively under preselected CT
conditions of operations.
16) Sensitivity Profile Means
The relative response of the CT x-ray system as a function of position along a line perpendicular
to the tomographic plane.
17) Single Tomogram System Means
A CT x-ray system which obtains x-ray transmission data during a scan to produce a single
tomogram.
18) Tomographic Plane Means
That geometric plane which the manufacturer identifies as corresponding to the output tomogram.
19) Tomographic Section Means
The volume of an object whose x-ray attenuation properties are imaged in a tomogram.
C. Information to be Provided for Users
Each manufacturer of a CT x-ray system shall provide the following technical and safety information, in
addition to that required under § 1020.30(h), to purchasers and, upon request, to others at a cost not to
exceed the cost of publication and distribution of such information. This information shall be identified and
provided in a separate section of the user's instruction manual or in a separate manual devoted only to
this information.
1) Conditions of Operation . A statement of the CT conditions of operation used to provide the
information required by paragraph (c) (2) and (3) of this section.