title: Experimental system for in-situ measurement of temperature rise in animal tissue under exposure to acoustic radiation force impulse.
abstract: OBJECTIVE
  Acoustic radiation force impulse (ARFI) has recently been used for tissue elasticity measurement and imaging. On the other hand, it is predicted that a rise in temperature occurs. In-situ measurement of temperature rise in animal experiments is important, yet measurement using thermocouples has some problems such as position mismatch of the temperature measuring junction of the thermocouple and the focal point of ultrasound. Therefore, an in-situ measurement system for solving the above problems was developed in this study.
  
  
  METHODS
  The developed system is composed mainly of an ultrasound irradiation unit including a custom-made focused transducer with a through hole for inserting a thin-wire thermocouple, and a temperature measurement unit including the thermocouple.
  
  
  RESULTS
  The feasibility of the developed system was evaluated by means of experiments using a tissue-mimicking material (TMM), a TMM containing a bone model or a chicken bone, and an extracted porcine liver. The similarity between the experimental results and the results of simulation using a finite element method (FEM) implied the reasonableness of in-situ temperature rise measured by the developed system.
  
  
  CONCLUSIONS
  The developed system will become a useful tool for measuring in-situ temperature rise in animal experiments and obtaining findings with respect to the relationship between ultrasound irradiation conditions and in-situ temperature rise.
authors.affiliation: Human Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-2-1 Namiki, Tsukuba, Ibaraki, 305-8564, Japan. n.nitta@aist.go.jp.
authors.forename: Naotaka
authors.initials: N
authors.lastname: Nitta
authors.affiliation: Department of Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0498, Japan.
authors.forename: Yasunao
authors.initials: Y
authors.lastname: Ishiguro
authors.affiliation: Department of Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0498, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Sasanuma
authors.affiliation: Department of Clinical Laboratory Medicine, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0498, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Taniguchi
authors.affiliation: Faculty of Life and Medical Sciences, Doshisha University, 1-3 Tatara Miyakodani, Kyotanabe, Kyoto, 610-0394, Japan.
authors.forename: Iwaki
authors.initials: I
authors.lastname: Akiyama
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000528:radiation effects; D054459:Elasticity Imaging Techniques; D006358:Hot Temperature; D008099:Liver / Q000528:radiation effects; D008954:Models, Biological
keywords: Acoustic radiation force impulse; In-situ measurement system; Temperature rise