title: Non-invasive speed of sound measurement in cartilage by use of combined magnetic resonance imaging and ultrasound: an initial study.
abstract: The speed of sound (SOS) is available as an index of elasticity. Using a combination of magnetic resonance imaging (MRI) and ultrasound, one can measure the SOS. In this study, we verified the accuracy of SOS measurements by using a combination of MRI and ultrasound. The accuracy of the thickness measurements was confirmed by comparison of the results obtained with use of MRI with those of a non-contact laser, and the accuracy of the calculated SOS values was confirmed by comparison of the results of the combined method and ultrasound measurements with the transmission method ex vivo. There was no significant difference between thickness measurements by MRI and those with the non-contact laser, and there was a significant linear correlation between SOS measurement results by use of the combined method and those by use of the transmission method. We also showed that the SOS values obtained agreed with those of previously published studies.
authors.affiliation: Department of Radiological Science, Graduate School of Human Health Science, Tokyo Metropolitan University, 7-2-10 Higashiogu, Arakawa-ku, Tokyo 116-855, Japan. t.aoki360@gmail.com
authors.forename: Takako
authors.initials: T
authors.lastname: Aoki
authors.forename: Naotaka
authors.initials: N
authors.lastname: Nitta
authors.forename: Akira
authors.initials: A
authors.lastname: Furukawa
mesh_terms: D000818:Animals; D002356:Cartilage / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D003198:Computer Simulation; D004548:Elasticity; D019220:High-Energy Shock Waves; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007717:Knee / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D007834:Lasers; D008279:Magnetic Resonance Imaging; D019047:Phantoms, Imaging; D013552:Swine; D014463:Ultrasonography / Q000295:instrumentation / Q000379:methods*