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Isochoic wave is a term used in ultrasound. Substances of a different medium are called isochoic if waves travel through them at the same speed. Isochoic in ultrasound means that two structures have the same echogenicity in 2D mode (B-mode).
Medical ultrasound includes diagnostic techniques (mainly imaging techniques) using ultrasound, as well as therapeutic applications of ultrasound. In diagnosis, it is used to create an image of internal body structures such as tendons, muscles, joints, blood vessels, and internal organs, to measure some characteristics (e.g., distances and velocities) or to generate an informative audible sound.
Time gain compensation (TGC) is a setting applied in diagnostic ultrasound imaging to account for tissue attenuation. [1] By increasing the received signal intensity with depth, the artifacts in the uniformity of a B-mode image intensity are reduced.
This allows for the detection of a pneumothorax with the absence of normal ‘lung-sliding’ and ‘comet-tail’ artifact (seen on the ultrasound screen). Compared with supine chest radiography , with CT or clinical course as the gold standard, bedside sonography has superior sensitivity (49–99% versus 27–75%), similar specificity (95 ...
Usually, there is an additional motion correction step to adjust for deformations caused by living subject. The motion artifact can be particularly problematic for clinical use. [5] Though ULM achieves resolutions under 10 micrometers, "motion in the body or from the ultrasound transducer can be several orders of magnitudes beyond this level".
Another imaging modality, which is ultrasound elastography, is also useful in diagnosing thyroid malignancy especially for follicular thyroid cancer. However, it is limited by the presence of adequate amount of normal tissue around the lesion, calcified shell around a nodule, cystic nodules, coalescent nodules.
By changing the pulse delays, the computer can scan the beam of ultrasound in a raster pattern across the tissue. Echoes reflected by different density tissue, received by the transducers, build up an image of the underlying structures. Weld examination by phased array. TOP: The phased array probe emits a series of beams to flood the weld with ...
Ultrasound is defined by the American National Standards Institute as "sound at frequencies greater than 20 kHz". In air at atmospheric pressure, ultrasonic waves have wavelengths of 1.9 cm or less. Ultrasound can be generated at very high frequencies; ultrasound is used for sonochemistry at frequencies up to multiple hundreds of kilohertz.