From Siemens Medical Systems;
'The SONOLINE Omnia™ ultrasound system offers mobility, high performance, and ease of use. This digital imaging system delivers excellent 2D, color flow, and Doppler image quality for a variety of general imaging exam types. In addition, the SONOLINE Omnia with cardiac option includes special features that enable use for adult cardiac imaging.'

Transducers can be divided in:
1.) Transducers where the sound wave is transmitted and received by different elements.
2.) Transducers where multiple elements part of the time transmit and part of the time receive sound energy.
The first type of ultrasound transducer is used in detection of blood flow (also called nonimaging transducers). For example, the continuous wave transducer (Pedoff transducer) has two separate elements, where one element is always transmitting while the other element is always receiving.
Probes of the second type are used to image cardiac structures and have the capability to use various Doppler techniques to detect blood flow (also called imaging transducers). For example, continuous wave, pulsed wave, high pulse repetition frequency, color flow, M-mode, and 2D-mode are the various modes that this type of transducer can perform.

Transducers can also be divided in mechanical and electronic or phased scan types.
Mechanical transducers use a combination of single element oscillation, multiple element rotation, or a single element and set of acoustic mirrors to generate the sweeping beam for 2D mode. Caused by the vibration (created as the mirrors rotate or oscillate inside the cover) is this type sometimes called the 'wobbler'. Mechanical transducers are cheaper than electronic transducers.
Different types of electronic or phased array probes can create a linear or rectangular shaped scan plane as well as a sector or pie shaped scan plane. Sector scanners are most useful for cardiac ultrasound examinations where the beam is directed between the ribs to image the heart. A linear array transducer is more useful in abdominal, OB/GYN, and small parts examinations. Electronic transducers are more expensive but they provide dynamic focusing and smaller probe.

See also Rectangular Array Transducer.

Ultrasound machines, widely used in medical imaging, are essential tools in the field of diagnostic ultrasound. These devices utilize high-frequency sound waves to create real-time images of internal body structures. Ultrasound machines consist of several key components that work together to generate diagnostic images. These include:
B-mode machines represent the vast majority of machines used in echocardiology, obstetrical scans, abdominal scans, gynecological scans, etc. B-mode ultrasound machines usually produce the sector (or pie segment-shaped) scans. These ultrasound scans require either a mechanical scanner transducer (the transducer moves to produce the sector scan), or a linear array transducer operated as a phased array.


Ultrasound machines come in different types, each catering to specific clinical needs. The two primary types are stationary and portable ultrasound machines:


See also Handheld Ultrasound, Ultrasound System Performance, Equipment Preparation, Coaxial Cable, and Microbubble Scanner Modification, Environmental Protection and Ultrasound Accessories and Supplies.

Unlike regular sound, ultrasound can be directed into a single direction. The echoes received by a stationary probe will result in a single dimensional signal showing peaks for every major material change.
To generate a 2D picture, the probe is swiveled, either mechanically or through a phased array of ultrasound transducers. The data is analyzed by computer and used to construct the image. In a similar way, 3D pictures can be generated by computer using a specialized probe. In this way, a photo of an unborn baby may be made.
Some ultrasonography machines can produce color pictures, of sorts. Doppler ultrasonography is color coded onto a gray scale picture. From the amount of energy in each echo, the difference in acoustic impedance can be calculated and a color is then assigned accordingly.

See also Densitometry and 3D Ultrasound.

As far as ultrasound is concerned, 4D ultrasound (also referred to as live 3D ultrasound or 4B-mode) is the latest ultrasound technology - the fourth dimension means length, width, and depth over time. 4D Ultrasound takes 3D ultrasound images and adds the element of time to the progress so that a moving three-dimensional image is seen on the monitor. A 4D scan takes the same amounts of time as a 2D or 3D scan; the difference is the ultrasound equipment being used. One advantage of a 4D fetal ultrasound to a 2D-mode is that parents can see how their baby will generally look like. However, there are different opinions over the medical advantages.
To scan a 3D ultrasound image, the probe is swept over the maternal abdomen. A computer takes multiple images and renders the 3D picture. With 4D imaging, the computer takes the images as multiple pictures while the probe is hold still and a 3D image is simultaneously rendered in real time on a monitor.
In most cases, the standard 2D ultrasound is taken, and then the 3D/4D scan capability is added if an abnormality is detected or suspected. The 3D/4D sonogram is then focused on a specific area, to provide the details needed to assess and diagnose a suspected problem. A quick 4D scan of the face of the fetus may be performed at the end of a routine exam, providing the parents with a photo.