1. Articles from Chuanqing Zhou

    1-18 of 18
    1. Retinal neurovascular responses to transcorneal electrical stimulation measured with optical coherence tomography

      Retinal neurovascular responses to transcorneal electrical stimulation measured with optical coherence tomography

      Noninvasive transcorneal electrical stimulation (TES) has emerged as a potential strategy to facilitate visual restoration and promote retinal cell survival for certain retinal and optic nerve diseases owing to its neuroprotective effects. However, the neurovascular responses of retinal neurons evoked by TES have not been completely determined. To investigate this issue, we utilized a custom-designed spectral-domain optical coherence tomography (SD-OCT) to record the retinal neural and vascular responses under TES in vivo simultaneously. Significant increases of both positive and negative intrinsic optical signal (IOS) changes were recorded in all three segmented retinal layers, which mainly related to neural activities. However ...

      Read Full Article
    2. Beyond Fourier transform: break the axial resolution limit in optical coherence tomography

      Beyond Fourier transform: break the axial resolution limit in optical coherence tomography

      Optical coherence tomography (OCT) is a volumetric imaging modality that empowers the clinicians and scientists to noninvasively visualize and examine the microscopic cross-sectional architectures of biological samples. By taking advantages of the coherence gating, OCT could achieve micrometer-level axial sectioning with high sensitivity. In the past decade, substantial efforts have been made to push the axial resolution of Fourier-domain OCT (FD-OCT) further into the sub-micron regime via physically extending the system’s spectral bandwidth. Here, we would like to offer a new perspective on this problem. We argue that the coupling between the axial resolution and the spectral bandwidth in ...

      Read Full Article
    3. In vivo time-serial evaluation of laser-induced choroidal neovascularization in rats simultaneously using photoacoustic microscopy and optical coherence tomography

      In vivo time-serial evaluation of laser-induced choroidal neovascularization in rats simultaneously using photoacoustic microscopy and optical coherence tomography

      Determination of the precise location and degree of condition of the Choroidal neovascularization (CNV) lesion is essential for diagnosation Neovascular age-related macular degeneration (AMD) and evaluation the efficacy of treatment. Given the complimentary contrast mechanisms of Photoacoustic microscopy (PAM) and Optical coherence tomography (OCT), the combination of PAM and OCT imaging could potentially provide much sensitive and specific detection of CNV. In this paper, we validated the opportunity to evaluate the information of laser-induced CNV and presented the in vivo time-serial evaluation of the CNV by simultaneously using PAM and OCT techniques. In vivo PAM and OCT examination was performed ...

      Read Full Article
    4. Response to Comment on “Retinal pulse wave velocity measurement using spectral-domain optical coherence tomography”

      Response to Comment on “Retinal pulse wave velocity measurement using spectral-domain optical coherence tomography”

      We noticed that Spahr et al. commented on our latest paper “Retinal pulse wave velocity measurement using spectral-domain optical coherence tomography”. In their comments, they concluded that the measured retinal pulse wave velocity (rPWV) in our paper was “highly surprising and contradictory to theoretical predictions and previously published results”. However, we have some different opinions regarding their comments.

      Read Full Article
      Mentions: Chuanqing Zhou
    5. Retinal pulse wave velocity measurement using spectral-domain optical coherence tomography

      Retinal pulse wave velocity measurement using spectral-domain optical coherence tomography

      The human eyes provide a natural window for noninvasive measurement of the pulse wave velocity (PWV) of small arteries. By measuring the retinal PWV, the stiffness of small arteries can be assessed, which may better detect early vascular diseases. Therefore, retinal PWV measurement has attracted increasing attention. In this study, a jump-scanning method was proposed for non-invasive measurement of retinal PWV using spectral-domain OCT. The jump-scanning method uses the phase-resolved Doppler OCT to obtain the pulse shapes. To realize PWV measurement, the jump-scanning method extracts the transit time of the pulse wave from an original OCT scanning site to another ...

      Read Full Article
    6. Dual band dual focus optical coherence tomography for imaging the whole eye segment

      Dual band dual focus optical coherence tomography for imaging the whole eye segment

      We developed an improved dual band dual focus spectral domain optical coherence tomography (SD-OCT) for in vivo 2D/3D imaging of the whole eye segment, including the whole anterior segment and retina. The system featured two OCT channels with two different bands centered at 840 nm and 1050 nm, which were designed to image the retina and the anterior segments of the eye, respectively. By combing the two probe light beams for co-axial scanning and separating them for focusing at different segments of the eye with a combination of three dichroic mirrors, we not only minimized the loss of the ...

      Read Full Article
    7. PEGylated Aucore–Agshell Nanorods as Optical Coherence Tomography Signal Nanoamplifiers

      PEGylated Aucore–Agshell Nanorods as Optical Coherence Tomography Signal Nanoamplifiers

      Optimizing contrast enhancement in optical coherence tomography (OCT) is essential for producing specific image signals and realizing its potential use in various biomedical imaging fields besides ophthalmology and cardiology. Using nanoparticles as selective signal nanoamplifiers will be helpful to highlight the lesion sites and identify cancerous changes that are difficult to diagnose currently. In this study, a quantitatively detailed analysis on the improvement of contrast enhancement and penetration depth of Au core –Ag shell nanorods (Au@Ag NRs) as OCT contrast agent was performed. The average A-scan data of the tissue was extracted and investigated. The signal to noise ratio ...

      Read Full Article
    8. Whole Eye Segment Imaging and Measurement With Dual-Channel Spectral-Domain OCT

      Whole Eye Segment Imaging and Measurement With Dual-Channel Spectral-Domain OCT

      BACKGROUND AND OBJECTIVES: To image and measure whole eye segments using dual-channel spectral-domain optical coherence tomography (SD-OCT) and to compare the results with those from the IOLMaster (Carl Zeiss Meditec, Dublin, CA). PATIENTS AND METHODS: Twenty eyes of 20 volunteers were recruited. Ocular dimensions, including cornea thickness, anterior chamber depth (ACD), lens thickness, anterior lens surface curvature, and axial length (AL), were calculated. The reproducibility of SD-OCT measurements, statistical significance of inter-instrument difference, correlation, and agreement were evaluated. RESULTS: No significant differences were found between independent SD-OCT measurements ( P > .05). The ACD and AL measured with IOLMaster were significantly shorter ...

      Read Full Article
    9. Dual illumination OCT at 1050nm and 840nm for whole eye segment imaging

      Dual illumination OCT at 1050nm and 840nm for whole eye segment imaging

      We presented an improved dual channel dual focus spectral domain optical coherence tomography (SD-OCT) with two illuminations at 840 nm and 1050 nm for whole eye segment imaging and biometry in vivo. The two light beams were coupled and optically optimized to scan the anterior and posterior segment of the eye simultaneously. This configuration with dichroic mirrors integrated in the sample arm enables us to acquire images from the anterior segment and retina effectively with minimum loss of sample signal. In addition, the full resolved complex (FRC) method was applied to double the imaging depth for the whole anterior segment ...

      Read Full Article
    10. Accommodation-induced variations in retinal thickness measured by spectral domain optical coherence tomography

      Accommodation-induced variations in retinal thickness measured by spectral domain optical coherence tomography

      To research retinal stretching or distortion with accommodation, accommodation-induced changes in retinal thickness (RT) in the macular area were investigated in a population of young adults ( n = 23 ) by using a dual-channel spectral domain optical coherence tomography (SD-OCT) system manufactured in-house for this study. This dual-channel SD-OCT is capable of imaging the cornea and retina simultaneously with an imaging speed of 24 kHz A-line scan rate, which can provide the anatomical dimensions of the eye, including the RT and axial length. Thus, the modification of the RT with accommodation can be calculated. A significant decrease in the RT ( 13.50 ...

      Read Full Article
    11. Dual-channel spectral-domain optical-coherence tomography system based on 3 × 3 fiber coupler for extended imaging range

      Dual-channel spectral-domain optical-coherence tomography system based on 3 × 3 fiber coupler for extended imaging range

      We have demonstrated a dual-channel multiplexing spectral-domain optical-coherence tomography (SD-OCT) system based on a 3 × 3 fiber coupler for extended imaging range of whole human eye depth, with a single light source and spectrometer. OCT images of anterior segments of a human eye were sequentially performed and constructed to demonstrate an extended depth range as large as 15 mm in air. A good quality OCT image of the whole anterior segment of an eye was present. Furthermore, whole eye segmental imaging was performed and ocular distances were calculated to show the validation of the system for whole eye morphological measurement.

      Read Full Article
    12. Evaluation of ultrasound and glucose synergy effect on the optical clearing and light penetration for human colon tissue using SD-OCT

      Evaluation of ultrasound and glucose synergy effect on the optical clearing and light penetration for human colon tissue using SD-OCT

      Topical application optical clearing agents (OCAs) can effectively enhance the tissue optical clearing on the human colon tissue, which has been demonstrated in our previous studies. Nevertheless, the strong light scattering still limits the diffusion rate of OCAs and penetration depth of light into the tissue. In this study, in order to further increase the diffusion of the OCA of glucose into tissue, we employ a method to improve the glucose permeability and light penetration with ultrasound (sonophoretic delivery, SP) and glucose (G) synergy on human normal and cancerous colon tissues in vitro, which was measured and quantified with spectral-domain ...

      Read Full Article
    13. Noninvasive Imaging and Measurement of Accommodation Using Dual-Channel SD-OCT

      Noninvasive Imaging and Measurement of Accommodation Using Dual-Channel SD-OCT

      Purpose : To investigate the feasibility and practicality of real-time noninvasive imaging and measurement of ocular accommodation (0–5D with one diopter step) using dual-channel , dual-focus spectral domain optical coherence tomography ( SD-OCT ). Materials and Methods : A custom-built, dual-channel , dual-focus SD-OCT was used to image the anterior segment, including the cornea, iris, and anterior and posterior lens surfaces. Three consecutive measurements were taken in each accommodative session for each subject. Changes in ocular dimensions during accommodation were calculated based on the acquired SD-OCT images . A Friedman test was used to test sensitivity of ocular dimension changes per diopter of accommodation . Results : With ...

      Read Full Article
    14. Ex vivo determination of glucose permeability and optical attenuation coefficient in normal and adenomatous human colon tissues using spectral domain optical coherence tomography

      Ex vivo determination of glucose permeability and optical attenuation coefficient in normal and adenomatous human colon tissues using spectral domain optical coherence tomography
      Recent reports have suggested that spectral domain optical coherence tomography (SD-OCT) is a useful tool for quantifying the permeability of hyperosmotic agents in various tissues. We report our preliminary results on quantification of glucose diffusion and assessment of the optical attenuation change due to the diffusion of glucose in normal and adenomatous human colon tissues in vitro by using a SD-OCT and then calculated the permeability coefficients (PC) and optical attenuation coefficients (AC). The PC of a 30% aqueous solution of glucose was 3.37 ± 0.23 × 10 − 6     cm / s in normal tissue and 5.65 ± 0.16 × 10 ...
      Read Full Article
    15. Optical coherence tomography for whole eye segment imaging

      Optical coherence tomography for whole eye segment imaging

      We proposed a dual focus dual channel spectral domain optical coherence tomography (SD-OCT) for simultaneous imaging of the whole eye segments from cornea to the retina. By using dual channels the system solved the problem of limited imaging depth of SD-OCT. By using dual focus the system solved the problem of simultaneous light focusing on the anterior segment of the eye and the retina. Dual focusing was achieved by adjusting the collimating lenses so the divergence of the two probing beams was tuned to make them focused at different depth in the eye. We further achieved full range complex (FRC ...

      Read Full Article
    16. In-vivo full depth of eye imaging spectral domain optical coherence tomography

      In-vivo full depth of eye imaging spectral domain optical coherence tomography

      It is necessary to apply the spectral-domain optical coherence tomography (SD-OCT) to image the whole eye segment for practically iatrical application, but the imaging depth of SD-OCT is limited by the spectral resolution of the spectrometer. By now, no result about this research has been reported. In our study, a new dual channel dual focus OCT system is adopted to image the whole eye segment. The cornea and the crystalline lens are simultaneously imaged by using full range complex spectral-domain OCT in one channel, the retina is detected by the other. The new system was successfully tested in imaging of ...

      Read Full Article
    17. Evaluation of spectrometric parameters in spectral-domain optical coherence tomography

      Evaluation of spectrometric parameters in spectral-domain optical coherence tomography

      The parameters of the spectrometer were analyzed in order to optimize the performance of spectral-domain optical coherence tomography (SD-OCT). Because probing depth is proportional to spectral resolution, it can be increased with the choice of a higher resolution spectrometer, which implies greater pixel numbers and lower imaging speed, or by sacrificing part of the spectrum, which compromises the axial resolution and side lobes. With a dynamic range of 8 bits or more, the signal-to-noise ratio remains constant for different noise levels. The results were verified experimentally with in vivo retinal SD-OCT imaging.

      Read Full Article
    18. Dual channel dual focus optical coherence tomography for imaging accommodation of the eye

      Dual channel dual focus optical coherence tomography for imaging accommodation of the eye

      A dual channel dual focus spectral-domain optical coherence tomography was developed for imaging the accommodation of the eye in real time. The system can provide simultaneous cross-sectional imaging of all the surfaces of the anterior segment of the eye including the cornea, anterior chamber, anterior and posterior surfaces of the crystalline lens. Thus, the modification of the curvatures of the anterior and posterior surfaces of the crystalline lens and the dimensions of the anterior segment ofthe eye with accommodation can be calculated. The system was successfully tested in imaging accommodation. The preliminary resultsdemonstrated the feasibility of this novel approach.

      Read Full Article
    1-18 of 18
  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. (17 articles) Shanghai Jiao Tong University
    2. (17 articles) Chuanqing Zhou
    3. (11 articles) Qiushi Ren
    4. (10 articles) Cuixia Dai
    5. (5 articles) Peking University
    6. (5 articles) Shuliang Jiao
    7. (4 articles) Qian Li
    8. (3 articles) University of Southern California
    9. (3 articles) Wenzhou Medical College
    10. (3 articles) Peng Xi
    11. (1 articles) University of Copenhagen
    12. (1 articles) Harvard University
    13. (1 articles) UC Irvine
    14. (1 articles) Massachusetts General Hospital
    15. (1 articles) University of Utah
    16. (1 articles) Mette Mogensen
  3. Popular Articles

  4. Picture Gallery

    Dual channel dual focus optical coherence tomography for imaging accommodation of the eye Evaluation of spectrometric parameters in spectral-domain optical coherence tomography In-vivo full depth of eye imaging spectral domain optical coherence tomography Optical coherence tomography for whole eye segment imaging Ex vivo determination of glucose permeability and optical attenuation coefficient in normal and adenomatous human colon tissues using spectral domain optical coherence tomography Noninvasive Imaging and Measurement of Accommodation Using Dual-Channel SD-OCT Evaluation of ultrasound and glucose synergy effect on the optical clearing and light penetration for human colon tissue using SD-OCT Dual-channel spectral-domain optical-coherence tomography system based on 3 × 3 fiber coupler for extended imaging range Accommodation-induced variations in retinal thickness measured by spectral domain optical coherence tomography Dual band dual focus optical coherence tomography for imaging the whole eye segment Combining Deep Learning With Optical Coherence Tomography Imaging to Determine Scalp Hair and Follicle Counts Efficacy and Safety of Laser‐Assisted Combination Chemotherapy: An Explorative Imaging‐Guided Treatment With 5‐Fluorouracil and Cisplatin for Basal Cell Carcinoma