Phased array transducers have revolutionized the field of ultrasound imaging by offering advanced diagnostic capabilities. Their ability to electronically steer beams without moving the probe provides unparalleled accuracy, making them invaluable tools in modern medicine.
This blog will explore how phased array transducers work, their benefits, and their widespread applications in medical diagnostics.
An Introduction to Phased Array Transducers
A phased array transducer, one of the most commonly used types of ultrasound transducers, gets its name from the specific arrangement of piezoelectric crystals known as a phased array. Phased array probes are designed to both emit and receive sound waves. They consist of multiple crystals (typically between 16 and 128), each capable of operating independently at frequencies between 2 and 7.5 MHz. Phased array probes emit a beam that usually starts narrow and expands into a fan or sector shape as it penetrates deeper into the body. This design enables the probe to scan large areas using a relatively small surface.
How Does a Phased Array Transducer Work?
As discussed earlier, all ultrasound transducers transmit sound waves into the body and receive echoes to create diagnostic images. Phased array ultrasound is beneficial in various applications, such as cardiac imaging.
For example, a phased array transducer is placed on the patient’s chest, and its multiple piezoelectric elements electronically steer the ultrasound beams in different directions without physically moving the probe. These beams reflect off the heart tissues, and the echoes are captured to produce real-time, high-resolution images. The system dynamically adjusts the focus of the beams for optimal clarity, especially for critical structures like heart valves. This allows doctors to assess blood flow and diagnose heart abnormalities without requiring invasive procedures.
What Are the Benefits of Phased Array Transducers?
Designed with advanced characteristics, phased array transducers offer several key benefits, including detailed, real-time images and versatile diagnostic options, improving accuracy and efficiency.
Noninvasive and detailed view
One key feature of phased array transducers is their noninvasive nature. They provide a detailed, real-time view of different body tissues from various angles without the need for invasive procedures.
Beam steering without moving the probe
Another key feature that makes transducers unique is their ability to electronically steer the ultrasound beams, which makes it easier to image various parts of the heart from a single position.
High precision
By electronically adjusting focus, phased array transducers improve image resolution to provide a clearer view of specific areas.
Versatile imaging options
Besides structural imaging, phased array probes can assess blood flow using Doppler imaging, providing a complete picture of the heart’s functionality.
Phased Array Transducers Applications
Similar to other types of ultrasound transducers, phased array probes have a variety of applications. Their versatility allows them to be used in a wide range of medical imaging scenarios, from cardiology to abdominal imaging and beyond, as we’ll elaborate on them below:
Cardiology
Phased array probes are widely used in cardiac examinations to produce detailed, real-time images of the heart. Their small footprint allows them to fit between the ribs, and the sector-shaped beam offers a comprehensive view of the heart’s chambers, valves, and vessels.
Abdominal Imaging
Phased array probes are also used for abdominal imaging, including the liver, gallbladder, kidneys, and pancreas. By steering the beam, healthcare professionals can obtain various views, making it easier to identify abnormalities like tumors, cysts, or gallstones.
Phased Array Transducers Vs. Convex Transducers
Phased array and convex transducers are two commonly used tools in medical imaging, each offering unique advantages depending on their application. To better understand the best type for our needs, below is a comprehensive comparison highlighting their key differences in design, functionality, and typical uses.
Piezoelectric Crystal Arrangement
Phased array transducers have multiple small piezoelectric crystals (containing 68 to 128 small crystals) arranged in a grid or linear format, allowing electronic control for beam steering and focusing. In contrast, convex transducers have crystals arranged in a curved pattern, delivering a wide, fan-shaped field of view, ideal for scanning large areas.
Frequency
Phased Array Transducers typically operate at higher frequencies and provide high-resolution images compared to convex transducers, which operate at lower frequencies and are designed for greater penetration depth but with slightly lower resolution.
Footprint
In the context of footprint, phased array transducers are designed with a narrow footprint, capturing small areas of the body, such as between the ribs in cardiac imaging. In contrast, convex transducers feature a larger, curved footprint designed to provide a broad field of view.
Applications
Phased array transducers are mostly utilized for cardiac examinations, while convex transducers are used when a larger area needs to be examined.
Top Phased Array Transducers Brands for Medical Imaging
Here are some of the most well-known and top brands of phased array transducers used in medical imaging:
- GE: Some popular GE brands are GE 3SC-RS and GE M5Sc-D.
- Fujifilm SonoSite: Some popular Fujifilm Sonosite brands are Fujifilm Sono site P21xp and Fujifilm Sonosite rP19xp.
- Philips: Some popular Philips brands are Philips S4-2 and Philips S5-1.
- Siemens: Some popular Simens brands are 4V1 and 4Z1C.
- Canon: Some popular Canon brands are PST-25ST and PVT-382MV.
The Bottom Line
Phased array transducers are innovative ultrasound devices that provide detailed, real-time images by electronically steering and focusing sound waves. Their ability to capture precise images of complex structures, such as the heart, without invasive procedures makes them a valuable tool in modern medical diagnostics, particularly in cardiology and abdominal imaging.
