Measurement of spatial distribution of refractive index in tissues by ultrasonic computer assisted tomography

• Published in: Ultrasound in medicine & biology Vol. 3; no. 4; pp. 327,337 - 335,339
• Main Authors: Greenleaf, James F., Johnson, Steven A., Lent, Arnold H.
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 1978
• Subjects: Acoustic attenuation; Acoustics; Adipose Tissue; Animals; Breast; Breast Neoplasms - diagnosis; Carcinoma - diagnosis; Dogs; Female; Humans; Mathematics; Muscles; Myocardium; Reconstruction; Refraction index; Time Factors; Tissues; Tomography, X-Ray Computed; Ultrasonography; Ultrasound; Velocity; Reconstruction; Tissues; Ultrasound; Velocity; Acoustic attenuation; Refraction index
• ISSN: 0301-5629; 1879-291X
• DOI: 10.1016/0301-5629(78)90075-3

Computerized tomography is used to calculate two independent images representing distributions of refractive index ( n) and acoustic attenuation (α) within 1–3 mm thick cross-sections through excised organs, including canine hearts and human breasts. Values of n and α are calculated from profiles of propagation times and amplitudes, respectively, of digitized acoustic pulses obtained by rectilinear transmission scans of the tissue at multiple angles of view. Images of the local speed of ultrasound show high values in regions of muscle, breast parenchyma, medullary carcinoma and connective tissue and show low values in regions of fat. Images of acoustic attenuation show high values in regions of connective tissue and borders of scirrhus carcinoma and low values in regions of fat.