Choosing the Best Transducer for Your Ultrasound Equipment

What an Ultrasound Transducer Does

Ultrasound transducers, also known as probes, are devices that create sound waves that bounce off of body tissues and then send back echoes. The transducer also serves the purpose of receiving the echoes it creates and then sending them on to the computer inside of an ultrasound system.

When the computer receives this information, it creates the image most people are familiar with, called a sonogram. The primary element of the ultrasound transducer is a piezoelectric crystal.

The technology of ultrasound transducers remained relatively unchanged for quite a few years. In the last few years, however, there have been significant advancements in the technology of these components.

The Various Parts of Transducers

Transducers come in all sizes and shapes and offer a wide range of features depending on your chosen model. This variety in types is because you often need various specifications to maintain image integrity through different body parts.

Transducers that are external pass over the outer surfaces of the body to create an image. Internal transducers are those that get inserted into an orifice in the body.

The transducer's construction features three parts that all play a role in how the transducer performs. The footprint of the transducer is the part of the probe that contacts the body, and this comes in various shapes and sizes.

The crystal arrangement inside the transducer gets affected by both the footprint and the shape of the ultrasound beam that needs to get created. The final part of the transducer is the frequency with higher frequencies offering greater image quality but less penetration into the body.

The Various Types of Transducers

One type of transducer is a linear transducer with the crystals aligned in a linear fashion. This transducer offers a rectangular beam shape and provides good near-field resolution.

Another type of transducer is a convex transducer that also can have the name curved transducer. The name comes from the fact that the alignment of the crystals is linear, but it's also curved. These transducers offer good in-depth penetration into the body.

Still another type of transducer is a phased array transducer. This transducer has a tiny footprint and also offers a lower frequency. What this means in use is a beam that is narrower but can also expand depending on the frequency used. The beam shape of this transducer is nearly triangular. 

Pencil transducers have a small footprint and often have the job of measuring blood flow. Endocavity transducers have the job of internal examinations of a patient.

The choice of which type of transducer to obtain often comes down to the procedure that needs to occur. It is not uncommon for a medical facility to have several different types of transducers. It is always important to ensure that any transducer you purchase is compatible with your current ultrasound system.