MORGATE BiomédicalApplications & Ressources > Fantômes d'Echographie en Mode B
Model 555 High Contrast phantom
Theory
In the very echo-rich environments, noise from the side- and grating loops might blur echo poor objects so that they might no be recognized. Tissue Harmonic Imaging, and similar techniques reduces this noise, and thereby improves contrast resolution.
Description and specifications.
The phantom mass is 12 cm wide, 15 cm high and 4 cm deep. The scan surface is 14 cm wide, thus allowing to test broad transducers.
The surface is protected by a 0,5 mm PP-plate that allow transmission fo ultrasound.
Phantom contains a very ekkorig background and a series of cylinders with an echo empty center. There are:
1 cylinder of 10 mm and 3 cylinders of 20 mm at distances of 2 cm - 12 cm from the surface all at -20 dB
1 cylinder of 10 mm and 3 cylinders of 20 mm at distances of 2 cm - 12 cm from the surface all at -30 dB
1 cylinder of 10 mm and 3 cylinders of 20 mm at distances of 2 cm - 12 cm from the surface all at -40 dB
Backscatteringen is measured relative to the background.
The attenuation in the background is approx. 0,5 dB / cm * MHz. For tolerances see data sheet.
Sound velocity is 1500 m / sec. For tolerances see data sheet.
Outside measurements 17 cm * 23 cm * 9 cm
Weight approx. 2,5 kg
Instruction
The phantom is elastic, so harmonics are not created inside the phantom-mass. Be sure to have a water pass between the transducer and the phantom surface to create the harmonics.
1) Adjust the gain so the echo poor areas of the cylinders are middel grey.
2) Notes whether it is possible to distinguish the echo empty center in the cylinders.
Maintenance:
Once every month inspect the phantom.
The surface must always be covered with 1/2 - 1 cm preservative fluid. Fluid that disappears by desiccation should be replaced by distilled water.
Once every 3 month replace the preservative fluid.
Please notice that the lid may not be 100 % tight. Drain fluid off before transportation, but never let it stay dry more than a few days.
The phantom will not stand frost. Safe storage temperature: 0 - 45 degrees Celsius.
Prescription for Preservative Fluid
-500 ml Distilled Water
- 2,5 g Acnibio OCS
- 0,5 g Citric ascid