Siemens SOMATOM Spirit Operator's Manual page 406

Constancy Test
Performing the pixel noise
test
F.3-22
The pixel noise is determined from two tomograms of the water
phantom in the same way as for the daily quality measurement.
F . 3
(→ Page F.2-1 Daily Quality Measurements)
Press the Start key on the control box.
✧
Scanning is started.
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i
After the previous test has been completed, the Noise test is
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started automatically.
Two images of the water phantom are recorded with identical
parameters. The difference between the first and the second
measurement is shown.
The following evaluations are displayed:
ROI
❏
Mean value of the CT value
❏
Sigma value (pixel noise)
❏
Quality Assurance
SOMATOM Spirit
F . 3
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F . 3
F . 3
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0 . 0
0 . 0
0 . 0