Do animals use B-ultrasound to check the probe of small animals?

The probe of veterinary B-ultrasound machine is a kind of equipment that converts one form of energy into another, which is called transducer. In ultrasound, sound waves are generated by electric charges, which make the piezoelectric disk in the probe vibrate. Piezoelectric comes from Greek, which means "pressure". Piezoelectric materials are piezoelectric materials, which change shape and size under an electric field, for example. Piezoelectric crystals are usually cylindrical, with a width of 1 ~ 2cm and a thickness of1mm. The current expands and contracts the crystal according to the polarity of the current, and this vibration will produce sound waves. The crystal also acts as a receiver, converting the reflected sound waves into electrical energy, which in turn is converted into modified radio waves, thereby producing an image on the screen. Other piezoelectric substances include barium titanate, lithium sulfate and lead zirconate. Barium titanate is most commonly used.

Sensors with different frequencies produce different penetration forces. The frequency range is1-25mhz; The frequencies of 3.5, 5.0 and 7.5 MHz are the most common. The high-frequency probe generates a short high-frequency wavelength (i.e. 7.5 MHz) to scan a short distance with clearer resolution, while the low-frequency probe generates a longer wavelength with greater beam penetration. Although these probes can scan deeper, the resolution will be reduced.

Different types of probes of animal B-ultrasound machine from Boxiang

echo

Ultrasonic waves are generated by the transducer and directed to the region of interest by holding the transducer above the region. Part of the sound wave will be absorbed by the tissue and part will be reflected. The reflection part produces an "echo" which is received by the sensor. Homogeneous media will produce many echoes, which are echo-producing areas, or no echoes, which are non-echo or non-echo areas. In tissues with poor echo, such as edema tissue, echo is scattered. Solid tumor is a kind of echo-rich tissue, which will produce many echoes at moderate sensitivity. Liquid is an anechoic medium, which appears black on the screen, while bones echo and appear white. Because a large number of sound waves pass through the liquid, tissues far away from the capsule area (filled with liquid) will have high echo.

Brightness mode or B-mode system uses gray imaging to display the echo as a point and display the two-dimensional cross section of the tissue. The second type of recording system, M mode or motion mode, will produce dots on the screen, which are regarded as lines. This line represents the distance from the reflector to the transducer. These lines are usually recorded on paper strips moving at a given speed. The trajectory is the same as the image on the screen and shows motion, such as contraction of the heart. The moving lines show the different positions of the valve and the size of the heart cavity that changes with the heart beating.

Current ultrasound systems use sector scanners or linear array transducers. These "real-time" scanners can observe motion by projecting continuous two-dimensional images. The sector scanner uses a crystal with a given frequency to be mounted on a shaft that rotates once. Only a part of the circle is open, sending and receiving signals in an arc. Therefore, the seen image is a part of the fan-shaped part of the tissue. Continuous rotation and pulse allow repeated imaging, displaying areas on the screen, and observing motion. Linear array sensors use multiple crystals mounted in a straight line along the length of the probe. The crystal is pulsed in sequence to produce a continuous scan to observe the movement.

Veterinary B-ultrasound image-B-ultrasound image of cow pregnancy

false appearance

The imaging quality is the best if the sound beam is perpendicular to the organ to be imaged. Tilting the probe will reduce the echo intensity and may lead to signal loss. Poor contact will produce unclear images. This can be prevented by shaving thick hair and using appropriate conductive adhesive to prevent any air from entering between the probe and the skin. If the sound beam is not perpendicular to the target organ, the reflected sound beam will appear wider than it and the image will be distorted. When the sound touches a highly reflective surface such as air or bone, reverberation illusion will appear. There will be a large echo artifact at the distal end of the bone surface, which will be displayed as an anechoic area immediately after strong echo. This is caused by crystal reverberation. Decreasing sensitivity will eliminate artifacts. If the scanning system needs to be adjusted, distortion may occur, but regular maintenance should avoid this problem.

Other uses of veterinary B-ultrasound machine

Recently, researchers used ultrasound to evaluate leg injuries in horses. Diagnostic ultrasound can determine the degree and relative age of tendon and ligament injuries in the distal limbs of horses. Observable changes of tendons, ligaments and surrounding soft tissues include changes in echo density, edge, thickness and internal characteristics. Advantages of ultrasound include more accurate recovery time prediction and improved accuracy in determining when animals can safely resume training without the risk of re-injury.