An array transducer is composed of multiple piezoelectric crystal elements arranged in an array. Arrays are transducer assemblies with a row of elements, used to focus the beam.

Types of array transducers:

See also Amplitude Shading, Transducer Types, and Transducer Assembly.

Cross-section scattering is a measure of the scattering strength of a point scatterer. The scattering strength is dependent on the size of the scatterer, the density and compressibility of the scatterer and the surrounding medium, and the ultrasound wavelength.
If a transducer emits ultrasound with a total acoustic power of P, and the power is assumed to be uniform distributed over the US beam cross-sectional area, then the ultrasound intensity at a certain range, is defined by:
I = P/A
where I is the intensity, and A is the cross-sectional beam area at that range.
A point scatterer located in the ultrasound beam at this range, will scatter the ultrasound with a total acoustic power of Ps, defined by:
Ps = I s
where s is the scattering cross-section of the point scatterer.

Process of conversion of continuous (analog) signals, such as the detected ultrasound or MRI signal (voltage), into numbers. This is carried out with an analog to digital converter.
There are two kinds of discretization involved: the voltage is only measured (sampled) at particular discrete times and only voltages within a particular range and separated by a particular minimum amount can be distinguished. Voltages beyond this range are said to exceed the dynamic range of the digitizer.

Ultrasound technology has evolved significantly, providing sonographers with a wide range of ultrasound machines. As technology has advanced, portable ultrasound equipment, including handheld ultrasound systems, have emerged in the field of medical imaging. However, these devices may have limited imaging capabilities and reduced image quality compared to larger systems.
Types of ultrasound systems compiled according to their portability:

In summary, pros and cons of portable ultrasound machines:

See also Ultrasound Accessories and Supplies, Environmental Protection, Sonographer, Ultrasound Technology and Equipment Preparation.

Ultrasound machines, with their various components and types, have revolutionized the field of medical imaging. These devices enable healthcare professionals to visualize internal structures, assess conditions, and guide interventions with real-time imaging capabilities. Today, medical ultrasound systems are complex signal processing machines. Assessing the performance of an ultrasound system requires understanding the relationships between the characteristics of the system, such as the point spread function, temporal resolution, and the quality of images. Image quality aspects include the detail resolution, contrast resolution and penetration. Systems with microbubble scanner modification are particularly suitable for contrast enhanced ultrasound.


In summary, ultrasound machines have diverse performance levels and corresponding price ranges, catering to various medical imaging needs. From low-performance systems with basic imaging capabilities to high-performance and premium systems with advanced features, ultrasound technology continues to advance healthcare imaging capabilities.
See also Ultrasound Physics, Handheld Ultrasound, Environmental Protection, Equipment Preparation.