The frequency range of ultrasonic diagnosis varies with different application requirements. For example, in the ultrasonic diagnosis of abdomen, the commonly used frequency range is 3.5MHz~5.0MHz. For the ultrasonic diagnosis of superficial organs, blood vessels and other small structures, higher resolution is needed, so the frequency of 7.5MHz~ 10MHz is often used. In the ultrasonic diagnosis of ophthalmology, due to the small structure of eyeball, high frequency is needed to obtain sufficient resolution, and the common frequency is 10MHz~20MHz.
The choice of frequency not only affects the resolution of the image, but also affects the penetration depth. Low-frequency ultrasound has deep penetration, which is suitable for large volume or deep penetration occasions, such as abdominal ultrasound. High-frequency ultrasound has high resolution and is suitable for diagnosing high details of surface organs and blood vessels.
Modern ultrasonic equipment usually has broadband technology, and the frequency can be adjusted within a certain range to meet the needs of different parts and diagnosis. This technology can improve the resolution and contrast of the image while ensuring the penetrating power, thus providing more accurate diagnostic information.
Advantages of ultrasonic diagnosis:
1, non-invasive: Ultrasonic diagnosis is a non-invasive examination method, which does not need to use invasive means, such as surgery or puncture. Patients will not feel pain or discomfort, and there is no need to worry about risks such as infection.
2. Real-time: Ultrasound examination can provide images in real time, so that doctors can immediately observe the situation in patients. This kind of real-time feedback helps doctors to make a diagnosis quickly and accurately.
3. Safety: Ultrasound is a non-radiation, non-invasive physical wave, which is harmless to human tissues. Even pregnant women and fetuses can be safely examined by ultrasound.
4. Portability: ultrasound equipment is small, light and easy to carry. This enables ultrasound examination to be performed in different medical environments, including clinics, hospitals and mobile medical facilities.
5. Economy: Compared with other medical imaging technologies, such as CT or MRI, ultrasonic diagnosis is usually more economical. It does not need expensive equipment and maintenance costs, so it can provide services for more patients.