Temperature elevation of biological tissue model exposed by focused ultrasound with acoustic radiation force

Author(s):  
Naotaka Nitta ◽  
Nobuki Kudo ◽  
Iwaki Akiyama
2017 ◽  
Author(s):  
Maria Karzova ◽  
Anastasia Nikolaeva ◽  
Sergey Tsysar ◽  
Vera Khokhlova ◽  
Oleg Sapozhnikov

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2252 ◽  
Author(s):  
Lulu Wang

Pathological changes in biological tissue are related to the changes in mechanical properties of biological tissue. Conventional medical screening tools such as ultrasound, magnetic resonance imaging or computed tomography have failed to produce the elastic properties of biological tissues directly. Ultrasound elasticity imaging (UEI) has been proposed as a promising imaging tool to map the elastic parameters of soft tissues for the clinical diagnosis of various diseases include prostate, liver, breast, and thyroid gland. Existing UEI-based approaches can be classified into three groups: internal physiologic excitation, external excitation, and acoustic radiation force (ARF) excitation methods. Among these methods, ARF has become one of the most popular techniques for the clinical diagnosis and treatment of disease. This paper provides comprehensive information on the recently developed ARF-based UEI techniques and instruments for biomedical applications. The mechanical properties of soft tissue, ARF and displacement estimation methods, working principle and implementation instruments for each ARF-based UEI method are discussed.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
M. Anthony Phipps ◽  
Sumeeth V. Jonathan ◽  
Pai-Feng Yang ◽  
Vandiver Chaplin ◽  
Li Min Chen ◽  
...  

Abstract The aim of this study was to improve the sensitivity of magnetic resonance-acoustic radiation force imaging (MR-ARFI) to minimize pressures required to localize focused ultrasound (FUS) beams, and to establish safe FUS localization parameters for ongoing ultrasound neuromodulation experiments in living non-human primates. We developed an optical tracking method to ensure that the MR-ARFI motion-encoding gradients (MEGs) were aligned with a single-element FUS transducer and that the imaged slice was prescribed at the optically tracked location of the acoustic focus. This method was validated in phantoms, which showed that MR-ARFI-derived displacement sensitivity is maximized when the MR-ARFI MEGs were maximally aligned with the FUS propagation direction. The method was then applied in vivo to acquire displacement images in two healthy macaque monkeys (M fascicularis) which showed the FUS beam within the brain. Temperature images were acquired using MR thermometry to provide an estimate of in vivo brain temperature changes during MR-ARFI, and pressure and thermal simulations of the acoustic pulses were performed using the k-Wave package which showed no significant heating at the focus of the FUS beam. The methods presented here will benefit the multitude of transcranial FUS applications as well as future human applications.


Sign in / Sign up

Export Citation Format

Share Document