How To Choose the Correct Ultrasound Probe

There are multiple probe options available on the market, which can make choosing the perfect probe difficult. Whether you want a new machine or a replacement, read on for how to choose the correct ultrasound. 

FREQUENCY

Materials made from ceramic crystals, called piezoelectrics, produce sound waves when supplied with an electrical current. These waves generate signals at a particular speed and distance, which are measured in MHz, or megahertz.

Speed and distance aren’t the only interactions that impact a transducer’s frequency. Reflection, refraction, scatter, attenuation, and a patient’s anatomy affect the sound waves in ultrasound.

The frequency range affects the quality of the images and make a huge difference in the clinical application required. Probes with a higher frequency, around 7 to 20 MHz, produce images with a higher resolution. Conversely, arrays with a lower range, (2 to 5MHz), will produce lower resolution but better deep penetration.

TYPE OF ARRAY

The array makes all the difference in both the image quality, and determines what type of probe you want based on clinical needs.

Arrays have four main formats. (There are more but these are the most popular). Each array format produces a specific kind of image.

A linear array will produce sharp, high-resolution images. It is used for vascular, breast, thyroid, and small parts examinations, along with Muscular-skeletal.

A micro-curved array will produce high-resolution images and is used mainly in women’s health applications. (OB/GYN, Prostate, etc.)

A phased array is a small footprint array with multiple stacks or layers. It is used for cardiac, deep abdominal, and some Trans-cranial examinations.

A curved or convex array is a high element count array, (192 to 6000 elements). They are used primarily in abdominal, OB, and general ultrasound applications.

CLINICAL APPLICATION

Another tip on how to choose the correct ultrasound is to know the clinical application you are planning to perform.

Probes are designed to fit the clinical application used. It also determines the style or shape of the array and other attributes of the probe design.

Linear probes operate at high frequencies. This allows for better superficial imaging and high resolution images. Uses: Vascular, MSK, Vein, Intra-lumen, Breast, Small parts.

Curved and Micro-curved probes operate at mid-range frequencies but still offer high-resolution images. Uses: OB/GYN, Prostate, Abdomen, 3D/4D, etc.

Phased probes operate at low frequencies. Resolution is lower, but deeper penetration is achieved. Uses: Cardiac, TCD, Deep Aorta

COMPATIBILITY

Before you purchase a probe, ensure its compatibility with the intended device. Newer types of transducers might not function with older, outdated machinery, and vice versa. Sometimes an Option code is required from the manufacturer.