1. Articles from Wenjuan Qi

    1-12 of 12
    1. Integrated multimodality intravascular imaging system that combines optical coherence tomography, ultrasound imaging, and acoustic radiation force optical coherence elastography

      Integrated multimodality intravascular imaging system that combines optical coherence tomography, ultrasound imaging, and acoustic radiation force optical coherence elastography

      An integrated intraluminal imaging system includes an optical coherence tomography interferometer (OCT), an ultrasound subsystem (US) and a phase resolved acoustic radiation force optical coherence elastography subsystem (PR-RAF-OCE). The steps include performing OCT to generate a returned optical signal, performing US imaging to generate a returned ultrasound signal, performing PRARF-OCE to generate a returned PR-ARF-OCE signal by generating a amplitude modulated ultrasound beam or chirped amplitude modulated ultrasound beam to frequency sweep the acoustic radiation force, measuring the ARF induced tissue displacement using phase resolved OCT, and the frequency dependence of the PR-ARF-OCE signal, processing the returned optical signal, the ...

      Read Full Article
      Mentions: UC Riverside
    2. Confocal acoustic radiation force optical coherence elastography using a ring ultrasonic transducer

      Confocal acoustic radiation force optical coherence elastography using a ring ultrasonic transducer

      We designed and developed a confocal acoustic radiation force optical coherence elastography system. A ring ultrasound transducer was used to achieve reflection mode excitation and generate an oscillating acoustic radiation force in order to generate displacements within the tissue, which were detected using the phase-resolved optical coherence elastography method. Both phantom and human tissue tests indicate that this system is able to sense the stiffness difference of samples and quantitatively map the elastic property of materials. Our confocal setup promises a great potential for point by point elastic imaging in vivo and differentiation of diseased tissues from normal tissue.

      Read Full Article
    3. Resonant Acoustic Radiation Force Optical Coherence Elastography

      Resonant Acoustic Radiation Force Optical Coherence Elastography

      We reported on the development of a resonant acoustic radiation force optical coherence elastography (ARF-OCE) technique that uses mechanical resonant frequency to characterize and identify tissues of different types. The results of resonant ARF-OCE imaging of a post-mortem human coronary artery with atherosclerosis demonstrate the potential of resonant ARF-OCE as a non-invasive method for imaging and characterizing vulnerable plaques. Knowledge of tissue mechanical properties provides valuable medical information in disease diagnosis and prognosis. There is a close correlation between tissue elasticity and pathology. For example, in atherosclerosis, measurement of tissue biomechanical properties has the potential to differentiate between various plaque ...

      Read Full Article
    4. Imaging and quantifying Brownian motion of micro- and nanoparticles using phase-resolved Doppler variance optical coherence tomography

      Imaging and quantifying Brownian motion of micro- and nanoparticles using phase-resolved Doppler variance optical coherence tomography

      Different types and sizes of micro- and nanoparticles have been synthesized and developed for numerous applications. It is crucial to characterize the particle sizes. Traditional dynamic light scattering, a predominant method used to characterize particle size, is unable to provide depth resolved information or imaging functions. Doppler variance optical coherence tomography (OCT) measures the spectral bandwidth of the Doppler frequency shift due to the Brownian motion of the particles utilizing the phase-resolved approach and can provide quantitative information about particle size. Spectral bandwidths of Doppler frequency shifts for various sized particles were quantified and were demonstrated to be inversely proportional ...

      Read Full Article
      Mentions: UC Irvine
    5. Imaging and quantifying Brownian motion of micro- and nanoparticles using phase-resolved Doppler variance optical coherence tomography

      Imaging and quantifying Brownian motion of micro- and nanoparticles using phase-resolved Doppler variance optical coherence tomography

      Different types and sizes of micro- and nanoparticles have been synthesized and developed for numerous applications. It is crucial to characterize the particle sizes. Traditional dynamic light scattering, a predominant method used to characterize particle size, is unable to provide depth resolved information or imaging functions. Doppler variance optical coherence tomography (OCT) measures the spectral bandwidth of the Doppler frequency shift due to the Brownian motion of the particles utilizing the phase-resolved approach and can provide quantitative information about particle size. Spectral bandwidths of Doppler frequency shifts for various sized particles were quantified and were demonstrated to be inversely proportional ...

      Read Full Article
      Mentions: UC Irvine
    6. Phase-resolved acoustic radiation force optical coherence elastography

      Phase-resolved acoustic radiation force optical coherence elastography

      Many diseases involve changes in the biomechanical properties of tissue, and there is a close correlation between tissue elasticity and pathology. We report on the development of a phase-resolved acoustic radiation force optical coherence elastography method (ARF-OCE) to evaluate the elastic properties of tissue. This method utilizes chirped acoustic radiation force to produce excitation along the sample’s axial direction, and it uses phase-resolved optical coherence tomography (OCT) to measure the vibration of the sample. Under 500-Hz square wave modulated ARF signal excitation, phase change maps of tissue mimicking phantoms are generated by the ARF-OCE method, and the resulting Young ...

      Read Full Article
    7. Feature Of The Week 12/18/11: UC Irvine Demonstrates Functional Imaging of Vibrating Vocal Folds with a High Speed OCT and ODT system

      Feature Of The Week 12/18/11: UC Irvine Demonstrates Functional Imaging of Vibrating Vocal Folds with a High Speed OCT and ODT system
      Vocal fold vibration is vital in voice production and the correct pitch of speech. University of California Irvine researchers have developed a high speed functional optical coherence tomography (OCT) system with a center wavelength of 1050 nm and an imaging speed of 100,000 A-lines per second and demonstrated imaging of the vibration of an ex-vivo swine vocal fold. High quality vocal fold images during vibration was demonstrated at an imaging speed of 100 frames per second. Functional information, such as vibration frequency and vibration amplitude, was obtained by analyzing the tissue surface during vibration. The axial direction velocity distribution ...
      Read Full Article
      Mentions: UC Irvine
    8. Imaging vibrating vocal folds with a high speed 1050 nm swept source OCT and ODT

      Imaging vibrating vocal folds with a high speed 1050 nm swept source OCT and ODT
      Vocal fold vibration is vital in voice production and the correct pitch of speech. We have developed a high speed functional optical coherence tomography (OCT) system with a center wavelength of 1050 nm and an imaging speed of 100,000 A-lines per second. We imaged the vibration of an ex-vivo swine vocal fold. At an imaging speed of 100 frames per second, we demonstrated high quality vocal fold images during vibration. Functional information, such as vibration frequency and vibration amplitude, was obtained by analyzing the tissue surface during vibration. The axial direction velocity distribution in the cross-sectional images of the ...
      Read Full Article
      Mentions: UC Irvine
    9. Intensity-based modified Doppler variance algorithm: application to phase instable and phase stable optical coherence tomography systems

      Intensity-based modified Doppler variance algorithm: application to phase instable and phase stable optical coherence tomography systems
      The traditional phase-resolved Doppler method demonstrates great success for in-vivo imaging of blood flow and blood vessels. However, the phase-resolved method always requires high phase stability of the system. In phase instable situations, the performance of the phase-resolved methods will be degraded. We propose a modified Doppler variance algorithm that is based on the intensity or amplitude value. Performances of the proposed algorithm are compared with traditional phase-resolved Doppler variance and color Doppler methods for both phase stable and phase instable systems. For the phase instable situation, the proposed algorithm demonstrates images without phase instability induced artifacts. In-vivo imaging of ...
      Read Full Article
      Mentions: UC Irvine
    10. In-vivo three-dimensional Doppler variance imaging for tumor angiogenesis on chorioallantoic membrane

      In-vivo three-dimensional Doppler variance imaging for tumor angiogenesis on chorioallantoic membrane
      Non-invasive tumor microvasculature visualization and characterization play significant roles in the detection of tumors and importantly, for aiding in the development of therapeutic strategies. The feasibility and effectiveness of a Doppler variance standard deviation imaging method for tumor angiogenesis on chorioallantoic membrane were tested in vivo on a rat glioma F98 tumor spheroid. Utilizing a high resolution Doppler Variance Optical Coherence Tomography (DVOCT) system with A-line rate of 20 kHz, three-dimensional mapping of a tumor with a total area of 3×2.5mm2 was completed within 15 seconds. The top-view image clearly visualized the complex vascular perfusion with the detection ...
      Read Full Article
      Mentions: UC Irvine
    11. Optimized doppler optical coherence tomography for choroidal capillary vasculature imaging

      Optimized doppler optical coherence tomography for choroidal capillary vasculature imaging
      In this paper, we analyzed the retinal and choroidal blood vasculature in the posterior segment of the human eye with optimized color Doppler and Doppler variance optical coherence tomography. Depth-resolved structure, color Doppler and Doppler variance images were compared. Blood vessels down to capillary level were able to be obtained with the optimized optical coherence color Doppler and Doppler variance method. For in-vivo imaging of human eyes, bulkmotion induced bulk phase must be identified and removed before using color Doppler method. It was found that the Doppler variance method is not sensitive to bulk motion and the method can be ...
      Read Full Article
      Mentions: UC Irvine
    12. Real-time bulk-motion-correction free Doppler variance optical coherence tomography for choroidal capillary vasculature imaging

      Real-time bulk-motion-correction free Doppler variance optical coherence tomography for choroidal capillary vasculature imaging
      In this paper, we analyze the retinal and choroidal blood vasculature in the posterior segment of the human eye with optimized color Doppler and Doppler variance optical coherence tomography. Depth-resolved structure, color Doppler and Doppler variance images are compared. Blood vessels down to the capillary level were detected and visualized with the optimized optical coherence color Doppler and Doppler variance method. For in-vivo imaging of human eyes, bulk-motion induced bulk phase must be identified and removed before using the color Doppler method. It was found that the Doppler variance method is not sensitive to bulk-motion and the method can be ...
      Read Full Article
      Mentions: UC Irvine
    1-12 of 12
  1. Categories

    1. Applications:

      Art, Cardiology, Dentistry, Dermatology, Developmental Biology, Gastroenterology, Gynecology, Microscopy, NDE/NDT, Neurology, Oncology, Ophthalmology, Other Non-Medical, Otolaryngology, Pulmonology, Urology
    2. Business News:

      Acquisition, Clinical Trials, Funding, Other Business News, Partnership, Patents
    3. Technology:

      Broadband Sources, Probes, Tunable Sources
    4. Miscellaneous:

      Jobs & Studentships, Student Theses, Textbooks
  2. Topics in the News

    1. (10 articles) UC Irvine
    2. (2 articles) University of Southern California
    3. (1 articles) UC Riverside
    4. (1 articles) Capital Medical University
  3. Popular Articles

  4. Picture Gallery

    Real-time bulk-motion-correction free Doppler variance optical coherence tomography for choroidal capillary vasculature imaging In-vivo three-dimensional Doppler variance imaging for tumor angiogenesis on chorioallantoic membrane Optimized doppler optical coherence tomography for choroidal capillary vasculature imaging Intensity-based modified Doppler variance algorithm: application to phase instable and phase stable optical coherence tomography systems Imaging vibrating vocal folds with a high speed 1050 nm swept source OCT and ODT Feature Of The Week 12/18/11: UC Irvine Demonstrates Functional Imaging of Vibrating Vocal Folds with a High Speed OCT and ODT system Phase-resolved acoustic radiation force optical coherence elastography Imaging and quantifying Brownian motion of micro- and nanoparticles using phase-resolved Doppler variance optical coherence tomography Imaging and quantifying Brownian motion of micro- and nanoparticles using phase-resolved Doppler variance optical coherence tomography Resonant Acoustic Radiation Force Optical Coherence Elastography Trojan-Horse Diameter-Reducible Nanotheranostics for Macroscopic/Microscopic Imaging-Monitored Chemo-Antiangiogenic Therapy Thickness of retinal pigment epithelium–Bruch’s membrane complex in adult Chinese using optical coherence tomography