What Is An Ultrasound Transducer?

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An ultrasound transducer is a device that produces the sound waves that are transmitted to the body and then bounce off tissue and organs to create echoes that are then translated to images of that specific part of the body.

They come in a variety of shapes and sizes for various requirements and create pictures of your body. It can be passed over external areas of the body or also inserted internally, whether it be vaginally or rectally.

Ultrasound Transducers

The transducers essential element is its crystal, which is responsible for generating and receiving the sound waves. They are constructed differently, depending on their aperture (or size or footprint of the actual part of the tool that comes into contact with your patient during the ultrasound), the arrangement of piezoelectric crystals, and the frequency at which they operate.

The following are the most commonly used for ultrasounds:

Sector Transducer
  • Phased-array of crystal arrangement.
  • Small footprint.
  • The beam shape is almost triangular.
  • Operates at a frequency of 1-5 MHz.
  • Generally used for the echocardiography and gynecological ultrasounds and other upper body functions.
Linear Transducer
  • Linear crystal arrangement.
  • Large footprint.
  • The beam shape is rectangular.
  • Operates at a frequency of 3-12 MHz.
  • Generally used for obstetrics, vascular, thyroid, or breast ultrasounds.
Convex Transducer
  • Curvilinear crystal arrangement.
  • Large footprint.
  • The beam shape will vary depending on distance and use.
  • Operates at a frequency of 1-5 MHz.
  • Can be used for any type of ultrasound (but not echocardiography). It is most commonly used for pelvic, lung, and abdominal ultrasounds.

Choosing The Right Transducer

The right transducer for you will depend on a few different factors – the frequency, the footprint, the frame rate, and its functionality.

Frequency – the frequency can impact how clear the image is. The higher the frequency the more detailed the images produced will be. This is because high frequency transducers penetrate more deeply into the area being examined.

Footprint – the footprint (aperture or size) is the part of the transducer that is in contact with the patient. A wide footprint can be challenging if you’re trying to hone into a small area, and obviously, internal ultrasounds will require specific transducers. Sector or annular are the smaller transducers, while convex and linear are large.

Frame Rate – the frame rate is how frequently the image updates. This can be an important aspect when you are carrying out ultrasounds with moving organs. A mechanical transducer would be the wrong tool for cardiac ultrasounds.

Functionality – many transducers will offer added functions, so you can consider additional functions if there are extras you might need for your practice.

The Importance of Transducers

Most people don’t realize that the ultrasound transducer is the most expensive part of an ultrasound machine and is by far the most important aspect of it. They should be treated with care, ensuring that they aren’t dropped, thrown, or knocked around. They should be wiped after each use and great care should be taken when sterilizing.