During an exam, ultrasonic beams propagate through a patient’s tissue by means of the transducer. As the beam propagates, there is a loss of energy through absorption, reflection, and scattering. This loss is displayed in the image as shadowing.
To start, shadowing may result due to the absorption or reflection of most of the energy. The degree of shadowing is dependent on the structure and size of the object that’s blocking the ultrasonic beam and its relativity to it. Shadowing is seen when objects smaller than the beam allows sufficient energy to bypass the reflector to permit good visualization of its posterior detail. This shadowing appears as a hypoechoic extension downward from a highly attenuating object. Primarily, this allows good …show more content…
The remaining wave passes through the object until it contacts the back surface, where part of it is reflected back to the transducer. This continues over and over, with sound wave “bouncing” off the object before returning to the transducer. The strength of the echo is continually decreasing, and the time it takes to return is prolonged, resulting in multiple objects of decreasing intensity appearing.
Acoustic enhancement occurs when sound passes through an area of very low acoustic impedance into tissue whose impedance is much higher. This appears as a hyperechoic region beneath tissues with abnormally low attenuation. Hyperechoic regions are brighter and the same color as the foreground of the image.
There are many pros and cons when it comes to shadowing in ultrasonic images. The pros of shadowing in ultrasound is that it can help determine different types of pathology. Some examples of these are seen in stones, cysts, and calcifications. As an example, stones in the pancreatic duct are often found in chronic pancreatitis. In gallstone disease, stones can block the pancreatic duct and even migrate into it, causing secondary acute pancreatitis. Calcifications are very common in cases of chronic pancreatitis. Dense calcifications and stones are revealed by distant shadowing. Shadowing can also help determine if cysts benign or malignant due to the shadows they produce. …show more content…
Since ultrasound transducers cannot see through air, this will result in a comet tail artifact and will cancel out parts of the image—this is a major con. Another example presented as con with shadowing is when an echo from a side lobe beam becomes strong enough and returns to the receiver. It is ‘assigned’ to the main beam and displayed at a false location. Anisotropy, another example, can make part of an image bright while an adjacent section that is not at right angles to the beam appears dark. This can give the impression that there is a tear present in the body. Although these examples are bad and can lead to misdiagnosis, familiarizing yourself with these different phenomenon’s and learning to change the angle of the probe, adjusting the machines depth, and adjusting the gain can sometime fix these issues; a
To start, shadowing may result due to the absorption or reflection of most of the energy. The degree of shadowing is dependent on the structure and size of the object that’s blocking the ultrasonic beam and its relativity to it. Shadowing is seen when objects smaller than the beam allows sufficient energy to bypass the reflector to permit good visualization of its posterior detail. This shadowing appears as a hypoechoic extension downward from a highly attenuating object. Primarily, this allows good …show more content…
The remaining wave passes through the object until it contacts the back surface, where part of it is reflected back to the transducer. This continues over and over, with sound wave “bouncing” off the object before returning to the transducer. The strength of the echo is continually decreasing, and the time it takes to return is prolonged, resulting in multiple objects of decreasing intensity appearing.
Acoustic enhancement occurs when sound passes through an area of very low acoustic impedance into tissue whose impedance is much higher. This appears as a hyperechoic region beneath tissues with abnormally low attenuation. Hyperechoic regions are brighter and the same color as the foreground of the image.
There are many pros and cons when it comes to shadowing in ultrasonic images. The pros of shadowing in ultrasound is that it can help determine different types of pathology. Some examples of these are seen in stones, cysts, and calcifications. As an example, stones in the pancreatic duct are often found in chronic pancreatitis. In gallstone disease, stones can block the pancreatic duct and even migrate into it, causing secondary acute pancreatitis. Calcifications are very common in cases of chronic pancreatitis. Dense calcifications and stones are revealed by distant shadowing. Shadowing can also help determine if cysts benign or malignant due to the shadows they produce. …show more content…
Since ultrasound transducers cannot see through air, this will result in a comet tail artifact and will cancel out parts of the image—this is a major con. Another example presented as con with shadowing is when an echo from a side lobe beam becomes strong enough and returns to the receiver. It is ‘assigned’ to the main beam and displayed at a false location. Anisotropy, another example, can make part of an image bright while an adjacent section that is not at right angles to the beam appears dark. This can give the impression that there is a tear present in the body. Although these examples are bad and can lead to misdiagnosis, familiarizing yourself with these different phenomenon’s and learning to change the angle of the probe, adjusting the machines depth, and adjusting the gain can sometime fix these issues; a