Anisotropy of ultrasonic backscatter from human tendon compared to that from normal human myocardium

• Published in: IEEE 1991 Ultrasonics Symposium pp. 1127 - 1131 vol.2
• Main Authors: Hoffmeister, B.K., Wong, A.K., Verdonk, E.D., Wickline, S.A., Miller, J.G.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 1991
• Subjects: Anisotropic magnetoresistance; Backscatter; Biological materials; Biopsy; Frequency measurement; Heart; Humans; Piezoelectric transducers; Tendons; Ultrasonic variables measurement
• DOI: 10.1109/ULTSYM.1991.234292

Anisotropy is a characteristic of ultrasonic backscatter observed in a number of materials containing directionally oriented fibers. It has been hypothesized that in heart the fibrous tissue collagen is a major determinant of backscatter. To investigate the effects of the orientation of collagenous fibers on ultrasonic backscatter, the authors studied excised human Achilles tendon, a tissue rich in collagen and exhibiting highly aligned fibers. The magnitude of anisotropy was quantified by measuring the integrated (frequency-averaged) backscatter in the fiber plane of cylindrical biopsy specimens taken from tendons. Tissue samples were insonified in a water bath around their entire circumference in 2 degrees steps with a 5-MHz center frequency piezoelectric transducer. Integrated backscatter was a maximum for insonification perpendicular to the fibers, and a minimum for insonification parallel to the fibers. Measurements of three formalin-fixed specimens revealed an average magnitude of anisotropy of 39+or-4 dB for tendon compared to 14.5+or-1.6 dB for normal regions of three fixed autopsied human hearts previously measured by the authors' laboratory.< >