Time-intensity based optoacoustic flow measurements with gold nanoparticles

Pai Chi Li, Chen Wei Wei, Chao Kang Liao, Hsiao Chien Tseng, Yen Ping Lin, Chia Chun Chen

研究成果: 雜誌貢獻Conference article

7 引文 斯高帕斯(Scopus)

摘要

The indicator-dilution theory has been used for flow rate measurements in various imaging modalities, including magnetic resonance imaging, computed tomography and ultrasound. The experimental procedure generally involves the injection of a dose of indicator (i.e., the contrast agent), after which the concentration of the agent is monitored as a function of time; it is therefore also known as the time-intensity method. Although the time-intensity method has been widely applied to other imaging modalities, it has not been demonstrated with optoacoustic imaging. In this study, we experimentally test the hypothesis that quantitative blood flow measurements are feasible with the time-intensity based method in optoacoustic imaging. Gold nanospheres (broad band absorption spectrum peaks at 520 nm) were used as the optoacoustic contrast agent. The imaging system consisted of a frequency-doubled Nd:YAG laser operating at 532 nm for optical illumination, and an ultrasonic single crystal transducer with a center frequency of 3.5 MHz and a focal depth of 7 cm for detection. The volumetric flow rate ranged from 0.23 to 4.29 ml/sec, and the volume of the mixing chamber was from 30 to 80 ml. Results show good agreement between the measured mean transit times and the predicted time constants (correlation coefficient higher than 0.88), thus demonstrating the feasibility of the time-intensity based flow measurement technique. In addition to describing the method and experimental results, issues regarding the system sensitivity and estimation of the dilution transfer function are also discussed.

原文英語
文章編號14
頁(從 - 到)63-72
頁數10
期刊Progress in Biomedical Optics and Imaging - Proceedings of SPIE
5697
DOIs
出版狀態已發佈 - 2005 八月 16
事件Sixth Conference on Biomedical Thermosacoustics, Optoacoustics, and Acousto-Optics - Photons Plus Ultrasound: Imaging and Sensing 2005 - San Jose, CA, 美国
持續時間: 2005 一月 232005 一月 25

    指紋

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Atomic and Molecular Physics, and Optics
  • Radiology Nuclear Medicine and imaging

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