@article{oai:nagoya.repo.nii.ac.jp:00015375,
 author = {SAKUMA, SADAYUKI and OKUMURA, YUTAKA and OHARA, KEN and ISHIGAKI, TAKEO},
 issue = {1-2},
 journal = {Nagoya Journal of Medical Science},
 month = {Nov},
 note = {This paper describes a method for calculating the elastic constant of tissue. Length measurements obtained from Ultrasonograms (US) are different from the results obtained from Computerized Tomograms (CT) when the velocity of sound is compared to standardized water measurements. The density of tissue ρt can be approximated by the equation. ρt = 1-Nc/Nair, where Nc and Nair are the CT-values of tissue and air respectively. The elastic constant (bulk modulus) Kt, sound velocity V, and density ρt are related through the following equation, V= (Kt/ρt)^0.5. The elastic constant Kt is then calculated by, Kt = Kw (Lc/Lu)^2・(1 - Nc/Nair), where Kw is the bulk modulus of water, and Lc and Lu are the measured distances from CT and US images respectively.},
 pages = {41--46},
 title = {The Elastic Constant of Tissue in the Body Estimated from Computerized Tomography and Ultrasonography : Theoretical Analysis},
 volume = {44},
 year = {1981}
}