1. Articles from quing zhu

    1-23 of 23
    1. 3D visualization of the ovarian tissue scattering coefficient with swept-source optical coherence tomography

      3D visualization of the ovarian tissue scattering coefficient with swept-source optical coherence tomography

      It is important to provide timely information to surgeons on diagnosis of a suspicious ovarian tissue before excision to avoid unnecessary surgery, especially for young women. In this report, we introduce a new 3-D surface mapping technique to map ovarian tissue scattering properties by fitting the swept-source optical coherence tomography (SS-OCT) signals to a scattering model. We observed that lower scattering coefficients and heterogeneous spatial distribution were associated with malignant ovarian tissues, and higher scattering coefficients and homogeneous spatial distribution indicated benign ovarian tissues. The initial results suggest that the 3-D scattering map has potential to be an effective tool ...

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      Mentions: Quing Zhu
    2. Classification of human ovarian tissue using full field optical coherence tomography

      Classification of human ovarian tissue using full field optical coherence tomography

      The feasibility of a full-field optical coherence tomography (FFOCT) system for rapid wide field optical analysis of normal and malignant human ovarian tissue pathologies was demonstrated. Five features were extracted from the normalized image histogram from 56 FFOCT images, based on the differences in the morphology of the normal and malignant tissue samples.

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    3. Classification and analysis of human ovarian tissue using full field optical coherence tomography

      Classification and analysis of human ovarian tissue using full field optical coherence tomography

      In this study, a full field optical coherence tomography (FFOCT) system was used to analyze and classify normal and malignant human ovarian tissue. 14 ovarian tissue samples (7 normal, 7 malignant) were imaged with the FFOCT system and five features were extracted by analyzing the normalized image histogram from 56 FFOCT images, based on the differences in the morphology of the normal and malignant tissue samples. A generalized linear model (GLM) classifier was trained using 36 images, and sensitivity of 95.3% and specificity of 91.1% was obtained. 20 images were used to test the model, and a sensitivity ...

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    4. Correlating optical coherence elastography based strain measurements with collagen content of the human ovarian tissue

      Correlating optical coherence elastography based strain measurements with collagen content of the human ovarian tissue

      In this manuscript, the initial feasibility of a catheter based phase stabilized swept source optical coherence tomography (OCT) system was studied for characterization of the strain inside different human ovarian tissue groups. The ovarian tissue samples were periodically compressed with 500 Hz square wave signal along the axial direction between the surface of an unfocused transducer and a glass cover slide. The displacement and corresponding strain were calculated during loading from different locations for each tissue sample. A total of 27 ex vivo ovaries from 16 patients were investigated. Statistically significant difference (p < 0.001) was observed between the average ...

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    5. Estimation of elastic parameters of ovarian tissue using phase stabilized swept source optical-coherence tomography

      Estimation of elastic parameters of ovarian tissue using phase stabilized swept source optical-coherence tomography

      We have estimated the micro-mechanical properties of ovarian tissue using phase-sensitive swept source optical coherence tomography. Ovary samples were mechanically excited by periodical vibration of an ultrasound transducer. The displacement and strain of the tissues were calculated during loading. Significant difference in strain was observed between the normal and malignant ovary groups, which indicates much softer and heterogeneous tissue structure for malignant ovaries. The initial results show that the phase sensitive swept source optical coherence elastography (OCE) can be an effective tool for characterization of stiffness and other micro-mechanical properties of normal and malignant ovarian tissue.

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    6. An overview of optical coherence tomography for ovarian tissue imaging and characterization

      An overview of optical coherence tomography for ovarian tissue imaging and characterization

      Ovarian cancer has the lowest survival rate among all the gynecologic cancers because it is predominantly diagnosed at late stages due to the lack of reliable symptoms and efficacious screening techniques. Optical coherence tomography (OCT) is an emerging technique that provides high-resolution images of biological tissue in real time, and demonstrates great potential for imaging of ovarian tissue. In this article, we review OCT studies for visualization and diagnosis of human ovaries as well as quantitative extraction of ovarian tissue optical properties for classifying normal and malignant ovaries. OCT combined with other imaging modalities to further improve ovarian tissue diagnosis ...

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    7. Indocyanine green enhanced co-registered diffuse optical tomography and photoacoustic tomography

      Indocyanine green enhanced co-registered diffuse optical tomography and photoacoustic tomography

      To overcome the intensive light scattering in biological tissue, diffuse optical tomography (DOT) in the near-infrared range for breast lesion detection is usually combined with other imaging modalities, such as ultrasound, x-ray, and magnetic resonance imaging, to provide guidance. However, these guiding imaging modalities may depend on different contrast mechanisms compared to the optical contrast in the DOT. As a result, they cannot provide reliable guidance for DOT because some lesions may not be detectable by a nonoptical modality but may have a high optical contrast. An imaging modality that relies on optical contrast to provide guidance is desirable for ...

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    8. A three-parameter logistic model to characterize ovarian tissue using polarization-sensitive optical coherence tomography

      A three-parameter logistic model to characterize ovarian tissue using polarization-sensitive optical coherence tomography

      Wang, Tianheng; Yang, Yi; Zhu, QuingIn this paper, a logistic prediction model is introduced to characterize the ovarian tissue. A new parameter, the phase retardation rate, was extracted from phase images of polarization-sensitive optical coherence tomography (PS-OCT). Statistical significance of this parameter between normal and ... [Biomed. Opt. Express 4, 772-777 (2013)]

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    9. Quantitative analysis of angle-resolved scattering properties of ovarian tissue using optical coherence tomography

      Quantitative analysis of angle-resolved scattering properties of ovarian tissue using optical coherence tomography

      Angle-resolved optical scattering properties of ovarian tissue, on different optical coherence tomography (OCT) imaging planes, were quantitatively measured by fitting the compounded OCT A-lines into a single scattering model. Higher cross correlation value of angle-resolved scattering coefficients between different OCT imaging planes was found in normal ovaries than was present in malignant ovaries. The mean cross correlation coefficient (MCC) was introduced in this pilot study to characterize and differentiate normal, n=6 , and malignant, n=4 , ovaries. A specificity of 100 percent and a sensitivity of 100 percent were achieved by setting MCC threshold at 0.6. Collagen properties, within ...

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    10. Assessment of collagen changes in ovarian tissue by extracting optical scattering coefficient from OCT images

      Assessment of collagen changes in ovarian tissue by extracting optical scattering coefficient from OCT images

      Optical scattering coefficient from ex-vivo unfixed normal and malignant ovarian tissue was quantitatively extracted by fitting optical coherence tomography (OCT) A-line signals to a single scattering model. 1097 average A-line measurements at a wavelength of 1310nm were performed at 108 sites obtained from 18 ovaries. The average scattering coefficient obtained from normal group consisted of 833 measurements from 88 sites was 2.41 mm-1 (±0.59), while the average coefficient obtained from malignant group consisted of 264 measurements from 20 sites was 1.55 mm-1 (±0.46). Using a threshold of 2 mm-1 for each ovary, a sensitivity of 100 ...

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    11. Feature Of The Week 10/23/11: Hybrid Intraoperative Probe Based on OCT and Positron Detection for Ovarian Cancer Detection

      Feature Of The Week 10/23/11: Hybrid Intraoperative Probe Based on OCT and Positron Detection for Ovarian Cancer Detection
      Multi-modality imaging involving OCT and one or more additional imaging technologies continues to show very promising results for increasing the diagnostic and interventional guidance capability of biomedical imaging probes. These synergistic effects have been published in numerous papers over the past year. This includes OCT in combination with fluorescence, Raman, NIR, ultrasound, and other technologies. Such approaches have the obvious disadvantage of increasing the cost and complexity of the imaging system but often that burden is offset by significantly increased performance. Recently a group from the University of Connecticut published a paper on a hybrid intraoperative probe that used OCT ...
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    12. Optical scattering coefficient estimated by optical coherence tomography correlates with collagen content in ovarian tissue

      Optical scattering coefficient estimated by optical coherence tomography correlates with collagen content in ovarian tissue
      Optical scattering coefficient from ex vivo unfixed normal and malignant ovarian tissue was quantitatively extracted by fitting optical coherence tomography (OCT) A-line signals to a single scattering model. 1097 average A-line measurements at a wavelength of 1310 nm were performed at 108 sites obtained from 18 ovaries. The average scattering coefficient obtained from the normal tissue group consisted of 833 measurements from 88 sites was 2.41 mm−1 (±0.59), while the average coefficient obtained from the malignant tissue group consisted of 264 measurements from 20 sites was 1.55 mm−1 (±0.46). The malignant ovarian tissue showed ...
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    13. Integrated optical coherence tomography, ultrasound and photoacoustic imaging for ovarian tissue characterization

      Integrated optical coherence tomography, ultrasound and photoacoustic imaging for ovarian tissue characterization
      Ovarian cancer has the lowest survival rate of the gynecologic cancers because it is predominantly diagnosed in Stages III or IV due to the lack of reliable symptoms, as well as the lack of efficacious screening techniques. Detection before the malignancy spreads or at the early stage would greatly improve the survival and benefit patient health. In this report, we present an integrated optical coherence tomography (OCT), ultrasound (US) and photoacoustic imaging (PAI) prototype endoscopy system for ovarian tissue characterization. The overall diameter of the prototype endoscope is 5 mm which is suitable for insertion through a standard 5-12.5mm ...
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    14. Polarization memory effect in optical coherence tomography and dental imaging application

      Polarization memory effect in optical coherence tomography and dental imaging application
      We report the existence of polarization memory effect (PME) in optical coherence tomography and investigate its potential applications in dental imaging. We performed the study in three steps. First, microsphere scattering phantoms of different sizes were imaged in order to validate experimental results with PME theory. Both linearly and circularly polarized light were used to probe the samples. Second, healthy tooth samples were scanned and polarization memory effect was identified in dentin. In this step, specific verification and signal processing were performed to rule out possible image interpretation by birefringence effect. Third, we evaluated dentin demineralization with PME. Results show ...
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    15. 3D imaging of dental hard tissues with Fourier domain optical coherence tomography

      3D imaging of dental hard tissues with Fourier domain optical coherence tomography
      A fiber optical coherence tomography (OCT) probe is used for three dimensional dental imaging. The probe has a lightweight miniaturized design with a size of a pen to facilitate clinic in vivo diagnostics. The probe is interfaced with a swept-source / Fourier domain optical coherence tomography at 20K axial scanning rate. The tooth samples were scanned from occlusal, buccal, lingual, mesial, and distal orientations. Three dimensional imaging covers tooth surface area up to 10 mm x 10 mm with a depth about 5 mm, where a majority of caries affection occurs. OCT image provides better resolution and contrast compared to gold ...
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    16. Potential role of a hybrid intraoperative probe based on OCT and positron detection for ovarian cancer detection and characterization

      Potential role of a hybrid intraoperative probe based on OCT and positron detection for ovarian cancer detection and characterization
      Ovarian cancer has the lowest survival rate of the gynecologic cancers because it is predominantly diagnosed in the late stages due to the lack of reliable symptoms and efficacious screening techniques. A novel hybrid intraoperative probe has been developed and evaluated for its potential role in detecting and characterizing ovarian tissue. The hybrid intraoperative dual-modality device consists of multiple scintillating fibers and an optical coherence tomography imaging probe for simultaneously mapping the local activities of 18F-FDG uptake and imaging of local morphological changes of the ovary. Ten patients were recruited to the study and a total of 18 normal, abnormal ...
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    17. A prototype hybrid intraoperative probe for ovarian cancer detection

      A prototype hybrid intraoperative probe for ovarian cancer detection
      A novel prototype intraoperative system combining positron detection and optical coherence tomography (OCT) imaging has been developed for early ovarian cancer detection. The probe employs eight plastic scintillating fiber tips for preferential detection of local positron activity surrounding a central scanning OCT fiber providing volumetric imaging of tissue structure in regions of high radiotracer uptake. Characterization measurements of positron sensitivity, spatial response, and position mapping are presented for Tl204/Cs137 sources as well as 18F-FDG. In conjunction with co-registered frequency domain OCT measurements the results demonstrate the potential for a miniaturized laparoscopic probe offering simultaneous functional localization and structural imaging ...
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    18. Minimization of geometric-beam broadening in a grating-based time-domain delay line for optical coherence tomography application

      This paper discusses a dispersion effect in a grating-based time-domain delay line that is different from the second- or higher-order dispersion in a grating-based Fourier-domain delay line. When the lateral broadening of the beam profile after grating dispersion exceeds the collection aperture of ... [J. Opt. Soc. Am. A 24, 3808-3818 (2007)]
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    19. Frequency tracking in optical Doppler tomography using an adaptive notch filter

      Optical Doppler tomography is a valuable functional extension of optical coherence tomography (OCT) that can be used to study subsurface blood flows of biological tissues. We propose a novel frequency estimation technique that uses an adaptive notch filter (ANF) to track the depth-resolved Doppler frequency. This new technique is a minimal-parameter filter and works in the time domain without the need of Fourier transformation. Therefore, the algorithm has a computationally efficient structure that may be well suited for implementation in real-time ODT systems. Our simulations and imaging results also demonstrate that this filter has good performance in terms of noise ...
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    20. Hybrid positron detection and optical coherence tomography system: design, calibration, and experimental validation with rabbit atherosclerotic models

      We evaluate the performance of our novel hybrid optical coherence tomography (OCT) and scintillating probe, demonstrate simultaneous OCT imaging and scintillating detection, and validate the system using an atherosclerotic rabbit model. Preliminary data obtained from the rabbit model suggest that our prototype positron probe detects local uptake of fluorodeoxyglucose (FDG) labeled with 18F positron (beta) radionuclide emitter, and the high-uptake regions correlate with sites of injury and extensive atherosclerosis areas. Preliminary data also suggest that coregistered high-resolution OCT images provide imaging of detailed plaque microstructures, which cannot be resolved by positron detection.
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    21. Characterization of dentin, enamel, and carious lesions by a polarization-sensitive optical coherence tomography system

      Enamel and dentin are the primary components of human teeth. Both of them have a strong polarization effect. We designed a polarization-sensitive optical coherence tomography (PSOCT) system to study the spatially resolved scattering and polarization phenomena of teeth. The system is constructed in free space to avoid the complexity of polarization control in fiber-based PSOCT. The structural features of enamel were evaluated in five human teeth that had no visible evidence of caries. The teeth were subsequently sectioned in mesial distal orientation and coronal orientation. Then the structural aspects of dentin were evaluated. OCT images were made of the mantel ...
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    22. Digital signal processor-based real-time optical Doppler tomography system

      We present a real-time data-processing and display unit based on a custom-designed digital signal processor (DSP) module for imaging tissue structure and Doppler blood flow. The DSP module is incorporated into a conventional optical coherence tomography system. We also demonstrate the flexibility of embedding advanced Doppler processing algorithms in the DSP module. Two advanced velocity estimation algorithms previously introduced by us are incorporated in this DSP module. Experiments on Intralipid flow demonstrate that a pulsatile flow of several hundred pulses per minute can be faithfully captured in M-scan mode by this DSP system. In vivo imaging of a rat's ...
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    23. Cancellation of coherent artifacts in optical coherence tomography imaging

      Coherent artifacts in optical coherence tomography (OCT) images can severely degrade image quality by introducing false targets if no targets are present at the artifact locations. Coherent artifacts can also add constructively or destructively to the targets that are present at the artifact locations. This constructive or destructive interference will result in cancellation of the true targets or in display of incorrect echo amplitudes of the targets. We introduce the use of a nonlinear deconvolution algorithm, CLEAN, to cancel coherent artifacts in OCT images of extracted human teeth. The results show that CLEAN can reduce the coherent artifacts to the ...
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    1-23 of 23
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  2. Topics in the News

    1. (23 articles) Quing Zhu
    2. (21 articles) University of Connecticut
    3. (11 articles) Tianheng Wang
    4. (10 articles) Molly Brewer
    5. (9 articles) Melinda Sanders
    6. (9 articles) Yi Yang
    7. (7 articles) Yueli L. Chen
    8. (5 articles) Nrusingh C. Biswal
    9. (5 articles) Daqing Piao
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    A prototype hybrid intraoperative probe for ovarian cancer detection Potential role of a hybrid intraoperative probe based on OCT and positron detection for ovarian cancer detection and characterization 3D imaging of dental hard tissues with Fourier domain optical coherence tomography Polarization memory effect in optical coherence tomography and dental imaging application Integrated optical coherence tomography, ultrasound and photoacoustic imaging for ovarian tissue characterization Optical scattering coefficient estimated by optical coherence tomography correlates with collagen content in ovarian tissue Feature Of The Week 10/23/11: Hybrid Intraoperative Probe Based on OCT and Positron Detection for Ovarian Cancer Detection Assessment of collagen changes in ovarian tissue by extracting optical scattering coefficient from OCT images Quantitative analysis of angle-resolved scattering properties of ovarian tissue using optical coherence tomography Direct inverse linearization of piezoelectric actuator’s initial loading curve and its applications in full-field optical coherence tomography (FF-OCT) Peripapillary Retinal and Choroidal Perfusion in Nonarteritic Ischemic Optic Neuropathy Using Optical Coherence Tomography Angiography Reliability of foveal avascular zone measurements in eyes with retinal vein occlusion using optical coherence tomography angiography