The imaging of the body began for the first time in 1885, when William Roentgen, who gave his name to the device, discovered the X-rays. Too many methods were used for imaging. One of them is ultrasound. many methods have been used.
What is Ultrasound?
Sound occurs as a result of vibration of objects. A higher frequency sound than the limit that the ear will hear is called ultrasound, also called ultrasound. In other words, acoustic waves on the frequency of sound that people can hear are called ultrasonic waves. Although it is generally defined between 20kHz and 100kHz, the upper limit in use in medicine goes up to 30 MHz.
Frequencies between 2-10 MHz are used for diagnostic purposes. Although it is in the same frequency band as the radio frequency waves, ultrasonic waves have a reflective pulsed structure. An electromagnetic wave occurs when a current (eg a 5 MHz signal) is passed through an antenna; The ultrasonic wave is created with a transducer (ultrasound).
How Does Ultrasound Work?
The produced ultrasonic waves are sent to the structure (body, organ) to be examined, the reflected waves are detected and displayed on the screen after processing. Thus, since there will be different reflections from each different environment and structure related to the internal structure of the body, the image information obtained can be distinguished. The propagation speed of the sound waves, the type of the environment, density, temperature and other factors determine. The denser the medium, the faster the spread rate.
The reflection and refraction of ultrasound waves occur on smooth and large surfaces. There are inhomogeneous and different density masses in the tissues. When the ultrasound wave hits such masses, it scatters and changes direction.
As the ultrasound beam passes through the tissues, its strength decreases. As the ultrasound beam passes through the tissues, its strength decreases. Three main factors lead to weakening, which leads to a decrease in the intensity of ultrasound waves, which loses some of its energy.
- The first is absorption. Some of the energy of ultrasound passing through the tissue is absorbed by the tissue, and the absorbed energy emerges as heat.
- The second factor is scattering. As a result of scattering, the amount of energy passing through the unit area decreases.
- The third factor is that the ultrasound beam expands and spreads after a certain distance.
Energy density is inversely proportional to the cross-sectional area. Since the cross-sectional area in the beam width will decrease, the energy density passing through the tissue decreases. The weakening of the ultrasound beam depends on the type, thickness and frequency of the wave. Attenuation increases with increasing tissue thickness and frequency. Low frequency ultrasound waves penetrate deeper tissues. Thus, ultrasound appears as a concept for imaging without any intervention. You can read our articles on technical information-technology-entrepreneurship by visiting our site.