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.

In the field of medical ultrasound imaging, the term 'probe' specifically refers to the ultrasound transducer and represent the handheld device that emits and receives ultrasound waves during an examination.
The probe encompasses various components such as the elements, backing material, electrodes, matching layer, and protective face that are responsible for both emitting and receiving the sound waves. Aperture, known also as the footprint, is the part of the probe that is in contact with the body. When the emitted sound waves encounter body tissues, they generate reflections that are received by the probe, which then generates a corresponding signal. In most cases, the probe emits ultrasound waves for only about 10% of the time and receives them for the remaining 90%.
Probes are available in different shapes and sizes to accommodate various scanning situations. The footprint is linked to the arrangement of the piezoelectric crystals and comes in different shapes and sizes e.g. linear array transducer//convex transducer. The transducer plays a huge role in image quality and is one of the most expensive parts of the ultrasound machine. Mechanical probes steer the ultrasound beam driven by a motor and are capable of producing high-quality images, but they are prone to wear and tear. Mechanical probes have been mostly replaced by electronic multi-element transducers, but mechanical 3D probes still remain for abdominal and Ob-Gyn applications.
In summary, the terms 'ultrasound transducer,' 'probe,' and 'scanhead' are often used interchangeably to refer to the same component of the ultrasound machine. Probes consist of multiple components and are available in different shapes and sizes depending on the sonographer's needs.

See also Handheld Ultrasound, Ultrasound System Performance, Omnidirectional, Probe Cleaning, and Multi-frequency Probe,

Equipment Preparation is an essential step in ensuring optimal ultrasound imaging quality and maintaining a safe and hygienic scanning environment. The following considerations should be taken into account:

By following these equipment preparation guidelines, healthcare professionals can ensure accurate and safe ultrasound examinations while promoting infection control measures and maintaining a hygienic environment for both patients and staff.
See also Environmental Protection, Portable Ultrasound Machine, Ultrasound Accessories and Supplies, and Ultrasound System Performance.

The acoustic lens is placed at the time the transducer is manufactured and cannot be changed. The acoustic lens is generally focused in the mid field rather than the near or far fields. The exact focal length varies with transducer frequency, but is generally in the range of 4-6 cm for a 5 MHz curved linear probe and 7-9 cm for a 3.5 MHz curved transducer.
Placing the elevation plane (z-plane) focal zone of the acoustic lens in the very near or far field would improve the beam width at precisely those depths. However, this would degrade the beam width to a much greater and unacceptable degree at all other depths.
There are some chemicals in ultrasound couplants that can degrade the acoustic lens, destroy bonding, or change the acoustic properties of the lens. Problematic chemicals include mineral oil, silicone oil, alcohol, surfactants, and fragrances. Fragrance can affect the transducer's acoustic lens or face material by absorption over time into elastomer and plastic materials, thus changing the material's weight, size, density, and acoustic impedance. Surfactants can degrade the bond between the lens and the piezoelectric elements and contribute to the accelerated degeneration of the lens.

See also Retrolenticular Afterglow.

The dead or ring down zone is the distance from the front face of the transducer to the first echo that is identifiable. The signals from this region are unsuitable. The dead zone is the result of transducer ringing and reverberations from the interface between the transducer and the scanned object. Impedance matching between the transducer and the receiver is important to avoid electrical ringing.
With an increase of the frequency, the pulse length and the depth of the dead zone decrease, if all other parameters remain constant. The acoustic power also affects the depth of the dead zone.