ULTRASOUND: ULTRASOUND PHANTOM: basics

What is an ultrasound phantom?

Any structure that contains one or more materials that simulate a body of tissue in its interaction with ultrasound and is used to mimic ultrasonic interactions in the human

body.

In medical imaging, phantoms are imaging specimens of known geometric & material composition and are commonly used in the development & characterization of imaging systems..

These are tissue mimicking because they have certain controlled and measured acoustic properties.

•Speed of Sound

•Attenuation Coefficient

•Back-scatter Coefficient/Relative Contrast

•Elasticity

•Thermal Properties

Why/ When we use it?

Most users of ultrasound, scan themselves or some other person when evaluating new ultrasound equipment for purchase or when testing current equipment, it can however be difficult objectively and quickly to assess whether a particular imaging problem is due to equipment or the persons being scanned.

In contrast to live model, the phantom is stable over time. With a phantom we can evaluate most of the factors decisive for image quality both objectively and subjectively.

Multiple tissue mimicking phantoms are used for a comprehensive QA program to evaluate the performance of ultrasound scanner.

Basics....

A phantom is used to evaluate an imaging device should be respond in a similar manner to how human tissues and organs would act in that specific imaging modality.Phantoms mimic the acoustic properties of human tissue.

Through visual inspection and a simple phantom scan, many deficiencies can be revealed such as: - deficiencies in image uniformity & quality

-deficiencies in penetration etc.

Phantom Construction

There is no standard ultrasound phantom.There are mainly two choices:

Rubber based ans Hydrogel based tissue mimicking materials.There are many,

different tissue mimicking phantom materials have been developed. Most commonly

phantoms were prepared by combining Gelatin and water.