Gammex 1425A, User Manual

10

9.

Scan the four grey scale targets and observe the difference in their grey levels. Adjust the 
gain control and observe how this affects the brightness of the targets. Notice how noise 
in the anechoic target becomes apparent as the gain increases. If your system has image 
“post-processing” capabilities, observe how the contrast between targets changes with 
different settings.

Adjust the gain control to the lowest noise level. This is the point at which you eliminate 
noise in the anechoic cyst (lower the gain until it just disappears). Record this gain setting 
and use it for future grey scale measurements. Freeze the image and visually evaluate 
the grey scale targets. Match each target with a step on the grey bar in the image. Make a 
hard copy and compare the hard copy with the image on the scanner.

10.

When you are done scanning the phantom, empty the water dam or completely clean off 
the coupling gel with a soft cloth or paper towel. 

Target Specifications

Low Scatter (Anechoic) Cysts

Diameters......................................................................................................................2, 4 and 6 mm
Placement.......................................................................................................... 4, 9 and 14 cm deep

Pin Targets

Diameter................................................................................................................................0.1 mm
Vertical spacing...........................................................................................20 mm at 3-17 cm deep 
Horizontal spacing................................................................................30 mm at 3 and 13 cm deep

Resolution Target Groups

...............................................................................................................4, 9 and 14 cm deep

All acoustic measurements made at 4.5 MHz, 22ºC.

Due to our philosophy of continuous quality improvement, 

all specifications are subject to change.