GE Optima XR646 - X-Ray Source Assembly Filtration; Dose;Dap Indication

Chapter 2: Safety and Regulatory
5495975-1EN Rev.9 2-47
© 2013-2017 General Electric Company. All rights reserved.
X-ray Source Assembly Filtration
The x-ray source assembly is comprised of the x-ray tube and collimator. Together they pro-
vide permanent, non-removable filtration of 2.7 mm aluminum equivalent @ 71 kVp. Addi-
tional collimator filtration is user selectable. Refer to Chapter 8: System Hardware Overview
-
Multi-Leaf Collimator (p. 8-26) for detailed information.
CAUTION This system is designed to be used with only the GE MX100 tube and col-
limator model number 5234954. Replacement of either of these compo-
nents with different types may render the system non-compliant to
applicable radiation safety standards and regulations.
Dose/DAP Indication
The Dose/DAP value is predicted by calculation. They are displayed on the image viewer for
each exposure. The Dose value is calculated at the position of patient entrance.
Figure 2-18 Block diagram for Dose/DAP calculation:
The nominal Dose is calculated at the calibrated distance, based on exposure techniques,
such as mAs, kVp and additional filtration. The final patient entrance dose is got by correcting
with SID and tube angle and the preset patient thickness.
DAP is got by multiplying Patient entrance dose and the image area at that distance.
Increase/decrease of the kVp, mAs, will lead to increase/decrease of Dose and DAP
Increase/decrease of the SID only, will lead to decrease/increase of Dose and DAP
Increase/decrease of the FOV only, will lead to increase/decrease of DAP, but Dose will not
change.
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