GE Senographe DS Manual page 706

GE Healthcare
Revision 1
Job Card ELE A037 - Image Acquisition and ACR Score
Fibers; More than half of the fiber is visible.
Masses; The mass does not appear circular, but is visible.
Specks; At least two specks are visible
- 0 For all other cases
7 PROCEDURE
1. Install the Bucky, with compression paddle.
2. Place the ACR phantom on the Bucky, against the chest wall
side and laterally centered.
3. Lightly compress the phantom with the compression paddle.
4. Check that the collimator is in full FOV and that the tube arm
angle is 0 degrees.
5. Enter the Phantom IQ test. From the Browser, click the QAP
button .
6. The system applies suitable parameters (Rh/Rh, 29 kV,
56 mAs, LF). Make an exposure and display the image.
7. The image appears with standard parameters which may
need adjusting for your system. Press the right mouse button to display a 2-item menu which allows
you to select the middle button function. Use it either to control brightness and contrast (window
length (WL) changes with vertical movement and window width (WW) changes with horizontal move-
ment) or to obtain the magnifying glass function. As a rough guide, it is suggested that the contrast is
adjusted to obtain an on-screen displayed value for WW of less than 200 for good viewing.
8. Obtain the best viewing conditions for an accurate assessment of the score. If necessary, complete
the test and repeat it with the phantom in a better position, and observe the 16 cells in the phantom
image. Note the ACR score (1, 0.5, or 0, as described in the Test Description above) for each cell,
and total the scores for each type of cell (fibers, masses, speck groups).
9. A group of three on-screen sliders are displayed at the top right of the screen. For each type of cell,
move the on-screen slider (with the cursor on the slider, press, and hold the mouse button while mov-
ing the mouse) until the correct score appears. Then click OK to enter the score into the system.
10. The results of the test are displayed in a format like that shown below. The LSL and USL columns
show the minimum acceptable score (Lower Specification Limit) and the maximum score (Upper
Specification Limit) for each item. The figures given here in the Measurement and Status columns
are for example only
Test
Masses
Speck groups
Fibers
Score
11. The test is successful if the total score is 11 or more, with scores for masses of at least 3, for speck
groups of at least 3, and for fibers of at least 4.
In the example shown the total score is 11.5, but the test fails because the speck group score is less
than 3.
12. If the test fails, repeat the flatfield test and then try again. If the flatfield test passes successfully but
the ACR Score test fails, the cause must be identified and corrected before further patient examina-
tions are made.
Chapter 7
Service Information and Procedures Class A 2385072-16-8EN
.
Measurement
4.00
2.50
5.00
11.50
LSL
3.00
3.00
4.00
11.00
Page no. 706
Senographe DS
USL Status
5.00 Passed
5.00 Failed
6.00 Passed
16.00 Passed
JC-ELE-A-037.fm