1. Articles from Nicusor Iftimia

    1-24 of 31 1 2 »
    1. Synchronized, concurrent optical coherence tomography and videostroboscopy for monitoring vocal fold morphology and kinematics

      Synchronized, concurrent optical coherence tomography and videostroboscopy for monitoring vocal fold morphology and kinematics

      Voice disorders affect a large number of adults in the United States, and their clinical evaluation heavily relies on laryngeal videostroboscopy, which captures the medial-lateral and anterior-posterior motion of the vocal folds using stroboscopic sampling. However, videostroboscopy does not provide direct visualization of the superior-inferior movement of the vocal folds, which yields important clinical insight. In this paper, we present a novel technology that complements videostroboscopic findings by adding the ability to image the coronal plane and visualize the superior-inferior movement of the vocal folds. The technology is based on optical coherence tomography, which is combined with videostroboscopy within the ...

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    2. Combined anatomical optical coherence tomography and intraluminal pressure reveal viscoelasticity of the in vivo airway

      Combined anatomical optical coherence tomography and intraluminal pressure reveal viscoelasticity of the in vivo airway

      It is hypothesized that the local, viscoelastic (time-dependent) properties of the airway are important to accurately model and ultimately predict dynamic airway collapse in airway obstruction. Toward this end, we present a portable, endoscopic, swept-source anatomical optical coherence tomography (aOCT) system combined with a pressure catheter to capture local airway dynamics in vivo during respiration. aOCT scans were performed in the airways of a mechanically ventilated pig under paralysis with dynamic and static ventilation protocols. Validation of dynamic aOCT luminal cross-sectional area (CSA) measurements against Cine CT, obtained during the same exam, showed an aggregate difference of 15  %    ±  3  %  . aOCT-derived ...

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    3. Evaluation of a Combined Reflectance Confocal Microscopy–Optical Coherence Tomography Device for Detection and Depth Assessment of Basal Cell Carcinoma

      Evaluation of a Combined Reflectance Confocal Microscopy–Optical Coherence Tomography Device for Detection and Depth Assessment of Basal Cell Carcinoma

      Importance The limited tissue sampling of a biopsy can lead to an incomplete assessment of basal cell carcinoma (BCC) subtypes and depth. Reflectance confocal microscopy (RCM) combined with optical coherence tomography (OCT) imaging may enable real-time, noninvasive, comprehensive three-dimensional sampling in vivo, which may improve the diagnostic accuracy and margin assessment of BCCs. Objective To determine the accuracy of a combined RCM-OCT device for BCC detection and deep margin assessment. Design, Setting, and Participants This pilot study was carried out on 85 lesions from 55 patients referred for physician consultation or Mohs surgery at Memorial Sloan Kettering Skin Cancer Center ...

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      Mentions: Nicusor Iftimia
    4. Investigation of tissue cellularity at the tip of the core biopsy needle with optical coherence tomography

      Investigation of tissue cellularity at the tip of the core biopsy needle with optical coherence tomography

      We report the development and the pre-clinical testing of a new technology based on optical coherence tomography (OCT) for investigating tissue composition at the tip of the core biopsy needle. While ultrasound, computed tomography, and magnetic resonance imaging are routinely used to guide needle placement within a tumor, they still do not provide the resolution needed to investigate tissue cellularity (ratio between viable tumor and benign stroma) at the needle tip prior to taking a biopsy core. High resolution OCT imaging, however, can be used to investigate tissue morphology at the micron scale, and thus to determine if the biopsy ...

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    5. Handheld optical coherence tomography–reflectance confocal microscopy probe for detection of basal cell carcinoma and delineation of margins

      Handheld optical coherence tomography–reflectance confocal microscopy probe for detection of basal cell carcinoma and delineation of margins

      We present a hand-held implementation and preliminary evaluation of a combined optical coherence tomography (OCT) and reflectance confocal microscopy (RCM) probe for detecting and delineating the margins of basal cell carcinomas (BCCs) in human skin in vivo . A standard OCT approach (spectrometer-based) with a central wavelength of 1310 nm and 0.11 numerical aperture (NA) was combined with a standard RCM approach (830-nm wavelength and 0.9 NA) into a common path hand-held probe. Cross-sectional OCT images and enface RCM images are simultaneously displayed, allowing for three-dimensional microscopic assessment of tumor morphology in real time. Depending on the subtype and ...

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    6. Integrating optical coherence tomography with laryngeal videostroboscopy

      Integrating optical coherence tomography with laryngeal videostroboscopy

      During clinical voice assessment, laryngologists and speech-language pathologists rely heavily on laryngeal endoscopy with videostroboscopy to evaluate pathology and dysfunction of the vocal folds. The cost effectiveness, ease of use, and synchronized audio and visual feedback provided by videostroboscopic assessment serve to maintain its predominant clinical role in laryngeal imaging. However, significant drawbacks include only two-dimensional spatial imaging and the lack of subsurface morphological information. A novel endoscope will be presented that integrates optical coherence tomography that is spatially and temporally co-registered with laryngeal videoendoscopic technology through a common path probe. Optical coherence tomography is a non-contact, micron-resolution imaging technology ...

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    7. Airway compliance measured by anatomic optical coherence tomography

      Airway compliance measured by anatomic optical coherence tomography

      Quantification of airway compliance can aid in the diagnosis and treatment of obstructive airway disorders by detecting regions vulnerable to collapse. Here we evaluate the ability of a swept-source anatomic optical coherence tomography (SSaOCT) system to quantify airway cross-sectional compliance (CC) by measuring changes in the luminal cross-sectional area (CSA) under physiologically relevant pressures of 10–40 cmH 2 O. The accuracy and precision of CC measurements are determined using simulations of non-uniform rotation distortion (NURD) endemic to endoscopic scanning, and experiments performed in a simplified tube phantom and ex vivo porcine tracheas. NURD simulations show that CC measurements are ...

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    8. Investigation of middle ear anatomy and function with combined video otoscopy-phase sensitive OCT

      Investigation of middle ear anatomy and function with combined video otoscopy-phase sensitive OCT

      We report the development of a novel otoscopy probe for assessing middle ear anatomy and function. Video imaging and phase-sensitive optical coherence tomography are combined within the same optical path. A sound stimuli channel is incorporated as well to study middle ear function. Thus, besides visualizing the morphology of the middle ear, the vibration amplitude and frequency of the eardrum and ossicles are retrieved as well. Preliminary testing on cadaveric human temporal bone models has demonstrated the capability of this instrument for retrieving middle ear anatomy with micron scale resolution, as well as the vibration of the tympanic membrane and ...

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    9. Combined reflectance confocal microscopy-optical coherence tomography for delineation of basal cell carcinoma margins: an ex vivo study

      Combined reflectance confocal microscopy-optical coherence tomography for delineation of basal cell carcinoma margins: an ex vivo study

      We present a combined reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) approach, integrated within a single optical layout, for diagnosis of basal cell carcinomas (BCCs) and delineation of margins. While RCM imaging detects BCC presence (diagnoses) and its lateral spreading (margins) with measured resolution of ∼ 1    μ m ∼1  μm , OCT imaging delineates BCC depth spreading (margins) with resolution of ∼ 7    μ m ∼7  μm . When delineating margins in 20 specimens of superficial and nodular BCCs, depth could be reliably determined down to ∼600    μ m ∼600  μm , and agreement with histology was within about ±50    μ m ±50  μm .

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    10. IMAGING WITH MULTIMODAL ADAPTIVE-OPTICS OPTICAL COHERENCE TOMOGRAPHY IN MULTIPLE EVANESCENT WHITE DOT SYNDROME: THE STRUCTURE AND FUNCTIONAL RELATIONSHIP

      IMAGING WITH MULTIMODAL ADAPTIVE-OPTICS OPTICAL COHERENCE TOMOGRAPHY IN MULTIPLE EVANESCENT WHITE DOT SYNDROME: THE STRUCTURE AND FUNCTIONAL RELATIONSHIP

      Purpose: To elucidate the location of pathological changes in multiple evanescent white dot syndrome (MEWDS) with the use of multimodal adaptive optics (AO) imaging . Methods: A 5-year observational case study of a 24-year-old female with recurrent MEWDS. Full examination included history, Snellen chart visual acuity, pupil assessment, intraocular pressures, slit lamp evaluation, dilated fundoscopic exam, imaging with Fourier-domain optical coherence tomography (FD-OCT), blue-light fundus autofluorescence (FAF), fundus photography, fluorescein angiography, and adaptive-optics optical coherence tomography . Results: Three distinct acute episodes of MEWDS occurred during the period of follow-up. Fourier-domain optical coherence tomography and adaptive-optics imaging showed disturbance in the photoreceptor ...

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    11. Hand scanning optical coherence tomography imaging using encoder feedback

      Hand scanning optical coherence tomography imaging using encoder feedback

      We present a new method for generating micron-scale OCT images of interstitial tissue with a hand scanning probe and a linear optical encoder that senses probe movement relative to a fixed reference point, i.e., tissue surface. Based on this approach, we demonstrate high resolution optical imaging of biological tissues through a very long biopsy needle. Minor artifacts caused by tissue noncompliance are corrected using a software algorithm which detects the simple repetition of the adjacent A-scans. This hand-scanning OCT imaging approach offers the physician the freedom to access imaging sites of interest repeatedly.

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    12. Low coherence interferometry approach for aiding fine needle aspiration biopsie

      Low coherence interferometry approach for aiding fine needle aspiration biopsie

      We present portable preclinical low-coherence interference (LCI) instrumentation for aiding fine needle aspiration biopsies featuring the second-generation LCI-based biopsy probe and an improved scoring algorithm for tissue differentiation. Our instrument and algorithm were tested on 38 mice with cultured tumor mass and we show the specificity, sensitivity, and positive predictive value of tumor detection of over 0.89, 0.88, and 0.96, respectively.

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    13. Detection of breast surgical margins with optical coherence tomography imaging: a concept evaluation study

      Detection of breast surgical margins with optical coherence tomography imaging: a concept evaluation study

      This study aimed to evaluate the concept of using high-resolution optical coherence tomography (OCT) imaging to rapidly assess surgical specimens and determine if cancer positive margins were left behind in the surgical bed. A mouse model of breast cancer was used in this study. Surgical specimens from 30 animals were investigated with OCT and automated interpretation of the OCT images was performed and tested against histopathology findings. Specimens from 10 animals were used to build a training set of OCT images, while the remaining 20 specimens were used for a validation set of images. The validation study showed that automated ...

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    14. Quantitative upper airway endoscopy with swept-source anatomical optical coherence tomography

      Quantitative upper airway endoscopy with swept-source anatomical optical coherence tomography

      Minimally invasive imaging of upper airway obstructions in children and adults is needed to improve clinical decision-making. Toward this goal, we demonstrate an anatomical optical coherence tomography (aOCT) system delivered via a small-bore, flexible endoscope to quantify the upper airway lumen geometry. Helical scans were obtained from a proximally-scanned fiber-optic catheter of 820 μm outer diameter and >2 mm focal length. Coupled with a long coherence length wavelength-swept light source, the system exhibited an SNR roll-off of < 10 dB over a 10 mm range. Operating at 10 rotations/s, the average accuracy of segmented cross-sectional areas was found to be ...

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    15. Optical coherence tomography-based micro-particle image velocimetry

      Optical coherence tomography-based micro-particle image velocimetry

      We present a new application of optical coherence tomography (OCT), widely used in biomedical imaging, to flow analysis in near-wall hydrodynamics for marine research. This unique capability, called OCT micro-particle image velocimetry, provides a high-resolution view of microscopic flow phenomena and measurement of flow statistics within the first millimeter of a boundary layer. The technique is demonstrated in a small flow cuvette and in a water tunnel.

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    16. Accurate prediction of collapse temperature using optical coherence tomography-based freeze-drying microscopy

      Accurate prediction of collapse temperature using optical coherence tomography-based freeze-drying microscopy

      The objective of this study was to assess the feasibility of developing and applying a laboratory tool that can provide three-dimensional product structural information during freeze-drying and which can accurately characterize the collapse temperature ( T c ) of pharmaceutical formulations designed for freeze-drying. A single-vial freeze dryer coupled with optical coherence tomography freeze-drying microscopy (OCT–FDM) was developed to investigate the structure and T c of formulations in pharmaceutically relevant products containers (i.e., freeze-drying in vials). OCT–FDM was used to measure the T c and eutectic melt of three formulations in freeze-drying vials. The T c as measured by ...

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    17. Combined reflectance confocal microscopy/optical coherence tomography imaging for skin burn assessment

      Combined reflectance confocal microscopy/optical coherence tomography imaging for skin burn assessment

      A combined high-resolution reflectance confocal microscopy (RCM)/optical coherence tomography (OCT) instrument for assessing skin burn gravity has been built and tested. This instruments allows for visualizing skin intracellular details with submicron resolution in the RCM mode and morphological and birefringence modifications to depths on the order of 1.2 mm in the OCT mode. Preliminary testing of the dual modality imaging approach has been performed on the skin of volunteers with some burn scars and on normal and thermally-injured Epiderm FTTM skin constructs. The initial results show that these two optical technologies have complementary capabilities that can offer the ...

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    18. Multimodal adaptive optics retinal imager: design and performance

      Multimodal adaptive optics retinal imager: design and performance

      Optical coherence tomography (OCT) and scanning laser ophthalmoscopy (SLO) are complementary imaging modalities, the combination of which can provide clinicians with a wealth of information to detect retinal diseases, monitor disease progression, or assess new therapies. Adaptive optics (AO) is a tool that enables correction of wavefront distortions from ocular aberrations. We have developed a multimodal adaptive optics system (MAOS) for high-resolution multifunctional use in a variety of research and clinical applications. The system integrates both OCT and SLO imaging channels into an AO beam path. The optics and hardware were designed with specific features for simultaneous SLO/OCT output ...

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    19. Cystic lesions of the pancreas: more reliable differentiation with in situ high-resolution optical imaging?

      Cystic lesions of the pancreas: more reliable differentiation with in situ high-resolution optical imaging?

      Pancreatic cystic lesions (PCLs) represent an increasingly common diagnostic and therapeutic challenge. A significant number of pancreatic cysts are detected incidentally when noninvasive abdominal imaging is performed for an unrelated diagnosis [1]. The vast majority of PCLs are cystic neoplasms (~60%), while injury or inflammation-related cysts (e.g., pseudocysts) account for approximately 30% of PCLs. The remaining PCLs are congenital or miscellaneous cysts [2]. Neoplastic cysts include intraductal papillary mucinous neoplasms (IPMNs), mucinous cystic neoplasms (MCNs), serous cystic neoplasms (SCNs), solid pseudopapillary neoplasms (SPNs), cystic endocrine neoplasms, ductal adenocarcinomas with cystic degeneration and acinar-cell cystic neoplasms [3]. Since the management ...

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    20. Speckle reduction in optical coherence tomography by path length encoded angular compounding

      Speckle reduction in optical coherence tomography by path length encoded angular compounding

      Apparatus for irradiating a sample, comprising an interferometer forwarding an electromagnetic radiation and a sample arm receiving the electromagnetic radiation, wherein the sample arm includes an arrangement which is configured to produce at least two radiations from the electromagnetic radiation so as to irradiate the sample, and to delay a first radiation of the at least two radiations with respect to a second radiation of the at least two radiations.

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    21. Imaging flow dynamics in murine coronary arteries with spectral domain optical Doppler tomography

      Imaging flow dynamics in murine coronary arteries with spectral domain optical Doppler tomography

      Blood flow in murine epicardial and intra-myocardial coronary arteries was measured in vivo with spectral domain optical Doppler tomography (SD-ODT). Videos at frame rates up to 180 fps were collected and processed to extract phase shifts associated with moving erythrocytes in the coronary arteries. Radial averaging centered on the vessel lumen provided spatial smoothing of phase noise in a single cross-sectional frame for instantaneous peak velocity measurement without distortion of the flow profile. Temporal averaging synchronized to the cardiac cycle (i.e., gating) was also performed to reduce phase noise, although resulting in lower flow profiles. The vessel angle with ...

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    22. Fluorescence-guided optical coherence tomography imaging for colon cancer screening: a preliminary mouse study

      Fluorescence-guided optical coherence tomography imaging for colon cancer screening: a preliminary mouse study

      A new concept for cancer screening has been preliminarily investigated. A cancer targeting agent loaded with a near-infrared (NIR) dye was topically applied on the tissue to highlight cancer-suspect locations and guide optical coherence tomography (OCT) imaging, which was used to further investigate tissue morphology at the micron scale. A pilot study on ApcMin mice has been performed to preliminarily test this new cancer screening approach. As a cancer-targeting agent, poly(epsilon-caprolactone) microparticles (PCLMPs), labeled with a NIR dye and functionalized with an RGD (argenine-glycine-aspartic acid) peptide, were used. This agent recognizes the ανβ3 integrin receptor (ABIR), which is over-expressed ...

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    23. Optical coherence tomography-based freeze-drying microscopy

      Optical coherence tomography-based freeze-drying microscopy

      A new type of freeze-drying microscope based upon time-domain optical coherence tomography is presented here (OCT-FDM). The microscope allows for real-time, in situ 3D imaging of pharmaceutical formulations in vials relevant for manufacturing processes with a lateral resolution of <7 μm and an axial resolution of <5 μm. Correlation of volumetric structural imaging with product temperature measured during the freeze-drying cycle allowed investigation of structural changes in the product and determination of the temperature at which the freeze-dried cake collapses. This critical temperature is the most important parameter in designing freeze-drying processes of pharmaceutical products.

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    1-24 of 31 1 2 »
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    1. (31 articles) Nicusor Iftimia
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    High resolution multimodal clinical ophthalmic imaging system Preliminary evaluation of a nanotechnology-based approach for the more effective diagnosis of colon cancers Advances in Optical Imaging for Clinical Medicine (Book) Differentiation of pancreatic cysts with optical coherence tomography (OCT) imaging: an ex vivo pilot study Fluorescence-guided optical coherence tomography imaging for colon cancer screening: a preliminary mouse study Imaging flow dynamics in murine coronary arteries with spectral domain optical Doppler tomography Cystic lesions of the pancreas: more reliable differentiation with in situ high-resolution optical imaging? Combined reflectance confocal microscopy/optical coherence tomography imaging for skin burn assessment Remote scanning for ultra-large field of view in wide-field microscopy and full-field OCT Inadequate Intimal Angiogenesis as a Source of Coronary Plaque Instability Comparison of optical coherence tomography angiography results of adult patients with Familial Mediterranean fever and healthy individuals Intravascular ultrasound or optical coherence tomography-defined anatomic severity and hemodynamic severity assessed by coronary physiologic indices