Focusing: electronic

Steer: none/ or electronic in doppler

Image shape: rectangle 

Element damage: vertical drop out

Commonly used: Vascular applications

The image is formed by sequencing tiny crystals across the face of the transducer when scanning in B-mode. This mode does not require steering, and the image is rectangular in shape. The field of view is equal to the width of the transducer.

The beams are guided using Phasing while employing Doppler imaging., Phasing is applied to small groups of crystals, creating create a parallelogram shape.

Phasing is done to the outer edge crystals when utilizing a wide scan or convex scan to direct the beam outward, creating a broader field of view and the trapezoid form.

The linear sequential array transducer features multi-focus capability and configurable focal points. This will improve the transducer's lateral resolution. A lens is used to achieve elevational resolution, which is fixed.

Focusing: electronic

Steer: electronic 

Image shape: sector 

Element damage: poor steering/focusing 

Commonly used: cardiac

The way a phased array steers a beam is using all of the elements of a phased pattern. The sound beam is steered if the spike line has a slope. Phased arrays have a curved pattern to create focusing during transmission. For each scan line, if just one focus is set, a single pulse pattern is sent to all elements. To create each new scan line, a new pattern is utilized to direct the beam until the full image is created.

The focal points of the phased array transducer can be adjusted, and it can multi-focus. This will improve the transducer's lateral resolution. A lens is used to achieve elevational resolution, which is fixed.

Focusing: fixed (achieved electronically)

Steer: Mechanical

Image shape:  sector 

Element damage: horizontal drop Out

Commonly used:  Cardiac

It included extra features that could be used to add more focus for better lateral and elevational resolution, as well as a change in depth of vision.

In the same way as a mechanical transducer, the image is created by moving the concentric rings to a different location for each scan line.

The pulse must be sent only once for each concentric ring in use.

 

The innermost center ring creates the shallowest focus on this area and is responsible for forming the near-field image. The next ring is used to generate the next deeper part of the image with its own focus if the depth is adjusted deeper. If the machine is set to maximum depth and contains four rings, each scan line will require four pulses. 

For this attribute, annular transducers have a superior lateral and elevational resolution but poor temporal resolution.

Focusing: electronic 

Steer: electronic 

Image shape: blunted sector 

Element damage: vertical drop out  

Commonly used:  Abdominal, Vascular & OB/GYN

The crystals are arranged side by side, similar to the linear sequence but on a curved surface. The edges of the transducer are curved outward to create a large field of view since the sound travels directly from the transducer surface. In the near field, the greater footprint of this transducer creates a larger field of view than the sector. While no steering is utilized in B-mode or color Doppler mode, a small amount of Phasing can be used to create a "wide scan" image.

The linear sequential array transducer features multi-focus capability and configurable focal points. This will improve the transducer's lateral resolution. A lens is used to achieve elevational resolution, which is fixed.

Focusing: electronic

Steer: electronic 

Image shape:  trapezoidal 

Element damage: poor steering and focusing

Commonly used:  Abdominal, Vascular, OB/GYN, & Cardiac 

Vector arrays can also be arranged in a  1 ½ D array

Vector transducers combine both principles by phasing tiny groups of elements while successively traveling over the transducer face. ( Linear sequential and phased array). Being able to steer beams in multiple directions.

The elevational resolution is improved when the vector array is arranged in a  1 ½ D  D pattern.