Siemens MAMMOMAT Novation DR Manual page 60

60
7. Measure the following values and add them to the table at step 4:
- dose value in the table above. The measured AEC dose values must be between:
H -> 120 µGy to 140 µGy
D -> 180 µGy to 200 µGy
- image pixel mean value
Display the image with the syngo Image Viewer. To do so, click the Viewing tab card,
load the image with the Patient -> Browser and select Tools -> Rectangle. Draw an
area of approximately 1 sq.cm and measure the pixel mean value. You have to
measure approximately 2 cm above the chest wall at the center of the detector.
Criteria: The expected pixel mean values are:
H = 250 ..... 350
D = 300 ..... 400
8. If the H & D dose settings have to be adjusted, proceed with Chapter 8 "Adjust the H
and D Settings" and repeat the H & D dose check for Mo/Mo again.
P
9. Record the measured values in the "Start-up Protocol" on
Check the H & D dose settings for Mo/Rh and W/Rh.
If the Mo/Mo AEC dose values for H & D are within the specification, proceed as follows:
1. Mount the collimator mounted plexi phantom.
X
2. Select the appropriate exposure parameters according to the table and start an expo-
sure.
3. Select the anode/filter combination according to the table and set the mAs (control con-
sole) as close as possible to the H & D mAs values (Mo/Mo) that you have measured in
step 2.
Display the image with the syngo Image Viewer. To do so, click the Viewing tab card,
load the image with the Patient -> Browser and select Tools -> Rectangle. Draw an
area of approximately 1 sq.cm and measure the pixel mean value.
Add the result to the table.
Tab. 13 Checking the H & D dose settings for Mo/Rh and W/Rh
Anode / Filter
Mo/Rh
W/Rh
The Mo/Rh and W/Rh pixel values must be as close as possible to the Mo/Mo pixel
values (see table at step 2).
The deviation must not exceed +/- 20 %.
4. If the H & D dose settings have to be adjusted, proceed with Chapter 8 "Adjust the H
and D Settings" and repeat the H & D dose checks for Mo/Rh and W/Rh again.
MAMMOMAT Novation DR
AEC
H
D
H
D
SPB7-250.815.06.02.02
12.05
Checking dose settings
(Start-up Protocol / p.
kV Pixel value
28 kV
28 kV
28 kV
28 kV
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97).
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