Principles of Medical Ultrasound Imaging Equipment (Rencheng Medical)

Various waves existing in nature can be mainly divided into two categories: electromagnetic waves and mechanical waves. Electromagnetic waves are the propagation process of changes in the electromagnetic energy field in the air, mainly including radio waves, visible light, and X-rays. Mechanical waves are the propagation process of mechanical vibration and mechanical force in a continuous elastic medium, mainly including sound waves, water waves, and seismic waves. Waves that propagate in a continuous medium, with a frequency f between 2x10~2x104Hz, which can cause people to feel sound, are called sound waves. Waves with frequencies between 10-4~20Hz are infrasonic waves, while waves with frequencies between 2x104~5x108Hz are ultrasonic waves. The waves mainly used in medical ultrasonic diagnostic ultrasound equipment are in the range of 2x105~4x107Hz, with common frequencies between 1MHz~10MHz, and wavelengths between 1.5mm~0.15mm.

Diagram of Electromagnetic Waves and Mechanical Waves

Ultrasound imaging is mainly based on the physical characteristics of ultrasonic waves propagating in a continuous medium. Black and white ultrasound is mainly based on two principles: Acoustic impedance characteristics: Different media have differences in sound velocity, wavelength, and density, forming acoustic impedance between media. Any medium has a boundary; when ultrasonic waves propagate in non-uniform tissue or from one tissue to another, an acoustic interface is formed due to the different acoustic impedance of the two media, allowing the ultrasound equipment to locate the position of organs and tissues.

Acoustic Attenuation Characteristics:When ultrasonic waves propagate in a medium, the ultrasonic energy gradually weakens with increasing distance. Sound waves are mainly attenuated through three pathways: diffusion attenuation, scattering attenuation, and absorption attenuation. The degree of ultrasonic attenuation is different between different tissues in the human body, so tissue structure information can be determined by ultrasound equipment through acoustic attenuation. It is because of this characteristic that we are usually asked to hold our urine when doing abdominal and uterine ultrasounds. This is because ultrasound has different echoes for liquid and air-containing tissues. When the bladder is full, the bladder and uterus can be distinguished by the liquid dark area and the substantial dark area. If the bladder is not full, the bladder and uterus will overlap, leading to misdiagnosis or missed diagnosis. Color Doppler ultrasound, also known as Doppler ultrasound, is based on black and white ultrasound and also uses Doppler effect imaging characteristics.

Doppler Characteristics:The Doppler effect was first discovered by the Austrian scientist Doppler. When a car is approaching you, the pitch seems higher; when the car is moving away from you, the pitch seems lower. Pitch is determined by the frequency of the sound wave; the higher the frequency, the higher the pitch, and the lower the frequency, the lower the pitch. However, the frequency is determined by the sound source; the actual frequency does not change, but the frequency difference occurs when the signal is received. Therefore, the phenomenon that the observer feels a change in frequency due to relative motion between the wave source and the observer is called the Doppler effect. Using the Doppler effect, ultrasonic Doppler instruments emit ultrasonic waves of known frequency; the ultrasonic waves are reflected by blood flow in blood vessels and received by the instrument, and by measuring the frequency of the reflected wave, the direction and velocity of blood flow can be reflected.

Diagram of Black and White Ultrasound and Color Doppler Ultrasound Imaging Physical Characteristics

Ultrasound diagnostic equipment uses the physical characteristics of ultrasound and the differences in the acoustic properties of human organs and tissues to display the physiological conditions of diseases in the form of waveforms, curves, or images, helping in disease diagnosis.
According to the imaging dimension of ultrasound echoes, it can be divided into one-dimensional, two-dimensional, three-dimensional, and four-dimensional ultrasound. One-dimensional ultrasound is less commonly encountered and has been eliminated or is only used for examinations in relatively narrow disease fields because the imaging is not intuitive enough. Two-dimensional ultrasound is the most familiar and widely used, mainly including "black and white ultrasound" and Doppler color ultrasound, which can use red and blue colors to mark blood flow conditions. The imaging principle of three-dimensional and four-dimensional ultrasound is to continuously acquire dynamic two-dimensional sectional images, process them through a computer, and rearrange them in a certain order to form three-dimensional and four-dimensional images of organs and tissues. Three-dimensional and four-dimensional ultrasound actually use two-dimensional observation and later image reconstruction. Compared with two-dimensional ultrasound, they are more intuitive and more detailed, such as fetal cleft lip, umbilical cord around the neck, etc. From a diagnostic point of view, two-dimensional ultrasound is sufficient to meet clinical needs, and three-dimensional and four-dimensional ultrasound do not significantly improve diagnostic value.

Diagram of Ultrasound Equipment Imaging Classification

With the rapid development, increasing convenience, and advancement of medical equipment, it facilitates disease diagnosis. The application of ultrasound is inseparable from the ultrasound workstation. It facilitates hospitals, doctors, and patients, enabling quick access to examination results, convenient film reading, archive viewing, saving, and archiving, improving the functions of case retrieval, statistics, and management. For patients, it enables quick access to examination information, visualizes images and videos, enhances communication with doctors, shares examination results data, and facilitates the access of archives during referral. Guangzhou Rencheng Medical stands out with more than ten years of experience in medical equipment repair, cooperating with hospitals and clearly understanding various needs from doctors. The developed image workstation serves hospitals, doctors, and patients well, integrating software system modules such as patient registration, image acquisition, diagnostic editing, report printing, image post-processing, case query, and statistical analysis. It enables quick access to examination information, visualizes images and videos, enhances communication with doctors, shares examination results data, and facilitates the access of archives during referral. Rencheng Image Workstation is currently recruiting national agents and distributors, and provides 24-hour After-sale Service.

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