title: Noninvasive thermometry assisted by a dual-function ultrasound transducer for mild hyperthermia.
abstract: Mild hyperthermia is increasingly important for the activation of temperature-sensitive drug delivery vehicles. Noninvasive ultrasound thermometry based on a 2-D speckle tracking algorithm was examined in this study. Here, a commercial ultrasound scanner, a customized co-linear array transducer, and a controlling PC system were used to generate mild hyperthermia. Because the co-linear array transducer is capable of both therapy and imaging at widely separated frequencies, RF image frames were acquired during therapeutic insonation and then exported for off-line analysis. For in vivo studies in a mouse model, before temperature estimation, motion correction was applied between a reference RF frame and subsequent RF frames. Both in vitro and in vivo experiments were examined; in the in vitro and in vivo studies, the average temperature error had a standard deviation of 0.7°C and 0.8°C, respectively. The application of motion correction improved the accuracy of temperature estimation, where the error range was 1.9 to 4.5°C without correction compared with 1.1 to 1.0°C following correction. This study demonstrates the feasibility of combining therapy and monitoring using a commercial system. In the future, real-time temperature estimation will be incorporated into this system.
authors.affiliation: University of California at Davis, Department of Biomedical Engineering, Davis, CA, USA.
authors.forename: Chun-Yen
authors.initials: CY
authors.lastname: Lai
authors.forename: Dustin E
authors.initials: DE
authors.lastname: Kruse
authors.forename: Charles F
authors.initials: CF
authors.lastname: Caskey
authors.forename: Douglas N
authors.initials: DN
authors.lastname: Stephens
authors.forename: Patrick L
authors.initials: PL
authors.lastname: Sutcliffe
authors.forename: Katherine W
authors.initials: KW
authors.lastname: Ferrara
mesh_terms: D000465:Algorithms; D000818:Animals; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000628:therapy; D005260:Female; D006979:Hyperthermia, Induced / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D051379:Mice; D009368:Neoplasm Transplantation; D019047:Phantoms, Imaging; D012685:Sepharose; D012815:Signal Processing, Computer-Assisted; D013696:Temperature; D013817:Thermography / Q000295:instrumentation / Q000379:methods*; D014159:Transducers; D014463:Ultrasonography / Q000295:instrumentation / Q000379:methods*
chemical_list: D012685:Sepharose