Konica Minolta CS-3 - Contrast to Noise Ratio (CNR) Check; Frequency; Procedure (for CS-3); Required Equipment

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2.6 Contrast to Noise Ratio (CNR) Check
2.6.1 Test Objective
To ensure that the CNR stays consistent over time, within a range at the same exposure setting, thereby conrming
that the performance of the mammography X-ray exposure system has not changed.
2.6.2 Frequency
• Initially before patients are imaged
• WEEKLY
2.6.3 Required Equipment
• Total 40 mm of PMMA (acrylic) phantom (Thickness: 10 mm or 20 mm)
• Al sheet (Thickness: 0.2 mm, Size: 60 mm × 60 mm or larger)
• Imaging cassette
2.6.4 Procedure (for CS-3)
1
Place PMMA (acrylic) phantom of thickness 40 mm on the breast support table.
2
Position the compression paddle as close as possible to the phantom surface.
3
Move the AEC sensor to its most forward position (closest to the chest side). Make an expo-
sure with 28kVp in AEC mode using Mo target.