What is anisotropy in ultrasound?
Anisotropy is the property of tendons, nerves and muscles to vary in their ultrasound appearance depending on the angle of insonation of the incident ultrasound beam. Loss of reflectivity in tendons may also denote underlying disease.
What equipment is used in ultrasound?
transducer
Ultrasound machines consist of a computer console, video monitor and an attached transducer. The transducer is a small hand-held device that resembles a microphone. Some exams may use different transducers (with different capabilities) during a single exam.
What causes anisotropy ultrasound?
Anisotropy occurs when the angle of the ultrasound beam is not perpendicular to the tissue being scanned. This causes the sound waves to be scattered rather than reflected back to the transducer/receiver; this results in loss of signal, which is presented as a hypoechoic area in linear structures such as tendons.
What is the most common artifact in MSK scanning?
The most common artifacts of the musculoskeletal system have been described, including those that diagnostically helpful, such as the presence of echo enhancement deep to a fluid-filled structure, or an acoustic shadow behind a calcification.
What is attenuation in ultrasound?
The amplitude and intensity of ultrasound waves decrease as they travel through tissue, a phenomenon known as attenuation. Given a fixed propagation distance, attenuation affects high frequency ultrasound waves to a greater degree than lower frequency waves.
What is anisotropy anatomy?
1. having unlike properties in different directions. 2.
What is attenuation in imaging?
Attenuation is the reduction of the intensity of an x-ray beam as it traverses matter. The reduction may be caused by absorption or by deflection (scatter) of photons from the beam and can be affected by different factors such as beam energy and atomic number of the absorber.
What is resolution in ultrasound?
Axial resolution Axial (also called longitudinal) resolution is the minimum distance that can be differentiated between two reflectors located parallel to the direction of ultrasound beam. Mathematically, it is equal to half the spatial pulse length. Axial resolution is high when the spatial pulse length is short.