Ultrasound Transducer Types

Learn from our Slideshare about the differences between ultrasound transducers. We also cover tips on how to treat your probes and how to select the right one.

1. Ultrasound Transducer Types - How to Select the Right Transducer

2. Produces sound waves that bounce off body tissues and make echoes. Receives the echoes and sends them to a computer that uses them to create an image called sonogram. How Does an Ultrasound Transducer Work?

3. Ultrasound Transducer Features Vary a lot, and have diverse features – different specifications are needed for maintaining image quality across different parts of the body. Can be either passed over the surface of the body – external transducers, or can be inserted into an orifice, such as the rectum or vagina – these are internal transducers. The ultrasound transducers differ in construction based on: Piezoelectric crystal arrangement; Aperture (footprint); Frequency Shape and Size Uses Construction

4. Ultrasound Transducer Types Linear Phased Array Endocavitary Convex Transeosophagal Pencil

5. Linear Transducers Piezoelectric crystal arrangement is linear, the shape of the beam is rectangular, and the near field resolution is good. The footprint, frequency, and applications depend on whether the product is for 2D or 3D imaging.

6. Linear Transducers – 2D Imaging A wide footprint, a central frequency – 2.5Mhz - 12Mhz. Used for various applications, such as vascular, blood vessel visualization, breast, thyroid, tendon, arthrogenous , intraoperative, laparoscopy, photoacoustic imaging, and ultrasonic velocity change imaging.

7. Linear Transducers – 3D imaging A wide footprint, a central frequency – 7.5Mhz - 11Mhz. Can be used for breast, thyroid, and arteria carotis of vascular application.

8. Convex Transducers Also called the curved transducer because the piezoelectric crystal arrangement is curvilinear. The beam shape is convex and the transducer is good for in depth examinations, even though the image resolution decreases when the depth increases.

9. Convex Transducers The footprint, frequency, and applications also depend on whether the product is for 2D or 3D imaging. There is a subtype called micro convex – with much smaller footprint, typically used in neonatal and pediatrics.

10. Convex Transducers – 2D imaging A wide footprint, central frequency – 2.5MHz - 7.5MHz. Can be used for abdominal examinations, transvaginal and transrectal examinations, and diagnosis of organs.

11. Convex Transducers – 3D imaging A wide field of view, a central frequency – 3.5MHz - 6.5MHz. Can be used for abdominal examinations.

12. Phased Array Transducers Piezoelectric crystal arrangement called phased-array – the most commonly used crystal. A small footprint and low frequency – its central frequency is 2Mhz - 7.5Mhz, beam point is narrow but it expands depending on the applied frequency. The beam shape is almost triangular and the near field resolution is poor.

13. Phased Array Transducers Can be used for cardiac examinations, including transesophageal examinations, abdominal and brain examinations.

14. Pencil Transducers Also called CW Doppler probes, utilized to measure blood flow and speed of sound in blood. This probe has a small footprint and uses low frequency of 2Mhz - 8Mhz.

15. Endocavitary Transducers Used for internal examinations of the patient, designed to fit in specific body orifices. The endocavitary transducers include endovaginal , endorectal , and endocavity transducers. Typically, they have small footprints and the frequency of 3.5Mhz - 11.5Mhz.

16. Transesophageal (TEE) Transducers Has a mall footprint, used for internal examinations – often employed in cardiology to obtain a better image of the heart through the oesophagus . Its frequency is mid-range: 3Mhz - 10Mhz.

17. Tips for Buying an Ultrasound Transducer Double check that the probe you are about to buy is compatible with the system you own. Penetration depth is better at a low frequency (between 2.5 and 7.5Mhz) but a disadvantage of the low frequency is a lower image quality. The higher the frequency (above 7.5Mhz), the lower is the depth of penetration, however, you get better quality images close to the surface (7.5MHz = 20 cm).

18. Tips for Buying an Ultrasound Transducer A black line on the screen of the ultrasound system will most likely mean that the transducer has a dead crystal inside. A shadow ultrasound screen could indicate a weak crystal inside the transducer that does not produce the necessary vibration. Avoid transducers with a crack, it will cause noise in the picture, a missing connection or lines in the image.

19. How To Treat Your Transducer? Do not throw, drop, or knock the transducer. Be careful not to damage the duct of the transducer. Wipe the gel from the transducer after each use. Do not sluice with alcohol-based liquids.

20. We hope that now you have a clear image of ultrasound transducer types and that you will be more prepared the next time you are purchasing probes. If you have any more questions about transducers, do not hesitate to contact our sales department by mail or phone . Questions? [email protected] Twitter: #LBNMedical Facebook : LBN Medical A/S