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- 2017
- spectral reconstruction
- interference
- polarization
- transform
- imaging spectrometer
- Optoelectronic Information Science and Engineering
- BITTT
- Zhejiang University
- Guilin University of Aerospace Technology
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In Vivo Rat Brain Imaging through Full-Field Optical Coherence Microscopy Using an Ultrathin Short Multimode Fiber Probe
摘要： We demonstrate full-field optical coherence microscopy (OCM) using an ultrathin forward-imaging short multimode fiber (SMMF) probe with a core diameter of 50 μm, outer diameter of 125 μm, and length of 7.4 mm, which is a typical graded-index multimode fiber used for optical communications. The axial and lateral resolutions were measured to be 2.14 μm and 2.3 μm, respectively. By inserting the SMMF 4 mm into the cortex of an in vivo rat brain, scanning was performed to a depth of 147 μm from the SMMF facet with a field of view of 47 μm. Three-dimensional (3D) OCM images were obtained at depths ranging from approximately 20 μm to 90 μm. Based on the morphological information of the resliced 3D images and the dependence of the integration of the OCM image signal on the insertion length, the obtained 3D information of nerve fibers has been presented.
关键词： medical optics instrumentation,full-field optical coherence microscopy,endoscopic imaging,fiber optics imaging
更新于2025-09-23 15:22:29
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Paired-Agent Fluorescence Molecular Imaging of Sentinel Lymph Nodes Using Indocyanine Green as a Control Agent for Antibody-Based Targeted Agents
摘要： Purpose. Paired-agent molecular imaging methods, which employ coadministration of an untargeted, “control” imaging agent with a targeted agent to correct for nonspecific uptake, have been demonstrated to detect 200 cancer cells in a mouse model of metastatic breast cancer. This study demonstrates that indocyanine green (ICG), which is approved for human use, is an ideal control agent for future paired-agent studies to facilitate eventual clinical translation. Methods. The kinetics of ICG were compared with a known ideal control imaging agent, IRDye-700DX-labeled antibody in both healthy and metastatic rat popliteal lymph nodes after coadministration, intradermally in the footpad. Results. The kinetics of ICG and antibody-based imaging agent in tumor-free rat lymph nodes demonstrated a strong correlation with each other (r = 0.98, p < 0.001) with a measured binding potential of -0.102 ± 0.03 at 20 min postagent injection, while the kinetics of ICG and targeted imaging agent shows significant separation in the metastatic lymph nodes. Conclusion. This study indicated a potential for microscopic sensitivity to cancer spread in sentinel lymph nodes using ICG as a control agent for antibody-based molecular imaging assays.
关键词： Paired-agent imaging,Antibody-based targeted agents,Control agent,Indocyanine green,Fluorescence molecular imaging,Sentinel lymph node
更新于2025-09-23 15:22:29
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Stimuli-Responsive Nanotheranostics for Real-Time Monitoring Drug Release by Photoacoustic Imaging
摘要： Molecular photoacoustic imaging (PA) is a promising technology to understand tumor pathology and guide precision therapeutics. Despite the capability of activatable PA probes to image tumor-specific biomarkers, limitations in their molecular structure hamper them from effective drug delivery and the drug release monitoring. Herein, we developed a perylene diimide (PDI) based theranostic platform that provides noninvasive PA imaging signals to monitor tumor-specific pH-responsive drug release. Methods: we first designed and synthesized an acid-responsive amine-substituted PDI derivative. The pH sensitive properties of the PDI was demonstrated by density functional theory (DFT) calculations, UV-vis experiments and PA studies. The theranostic platform (THPDINs) was fabricated by self-assembly of the acid-responsive PDI, a pH irrelevant IR825 dye, and anti-cancer drug doxorubicin (DOX). The PA properties in various pH environment, drug delivery, cytotoxicity, cell uptake, ratiometric PA imaging and anti-tumor efficacy of the THPDINs were investigated in vitro and in vivo by using U87MG glioma cell line and U87MG tumor model. Results: We found that our designed PDI was sensitive to the tumor specific pH environment, reflected by absorbance shift, PA intensity and aggregation morphology changes in aqueous solution. The as-synthesized pH sensitive PDI acted as a molecular switch in the THPDINs, in which the switch can be triggered in the mild acidic tumor microenvironment to accelerate DOX release. Meanwhile, the DOX release could be monitored by ratiometric PA imaging. Conclusions: We developed a multifunctional PDI based theranostic platform for noninvasive real-time ratiometric PA imaging of tumor acidic pH and monitoring of drug release in living mice simultaneously. This strategy will shed light on the development of smart activatable theranostic nanoplatforms and will significantly advance the application of PA theranostics in biology and medicine.
关键词： photoacoustic imaging,drug delivery,pH-responsive,ratiometric imaging,theranostics
更新于2025-09-23 15:22:29
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Hydrophilic, Red-Emitting, and Thermally Activated Delayed Fluorescence Emitter for Time-Resolved Luminescence Imaging by Mitochondrion-Induced Aggregation in Living Cells
摘要： Thermally activated delayed fluorescence (TADF) materials have provided new strategies for time-resolved luminescence imaging (TRLI); however, the development of hydrophilic TADF luminophores for specific imaging in cells remains a substantial challenge. In this study, a mitochondria-induced aggregation strategy for TRLI is proposed with the design and utilization of the hydrophilic TADF luminophore ((10-(1,3-dioxo-2-phenyl-2,3-dihydro-1H-benzo[de]isoquinolin-6-yl)-9,9-dimethyl-9,10-dihydroacridin-2-yl)methyl)triphenylphosphonium bromide (NID-TPP). Using a nonconjugated linker to introduce a triphenylphosphonium (TPP+) group into the 6-(9,9-dimethylacridin-10(9H)-yl)-2-phenyl-1H-benzo[de]isoquinoline-1,3(2H)-dione (NID) TADF luminophore preserves the TADF emission of NID-TPP. NID-TPP shows clear aggregation-induced delayed fluorescence enhancement behavior, which provides a practical strategy for long-lived delayed fluorescence emission in an oxygen-containing environment. Finally, the designed mitochondrion-targeting TPP+ group in NID-TPP induces the adequate accumulation of NID-TPP and results in the first reported TADF-based time-resolved luminescence imaging and two-photon imaging of mitochondria in living cells.
关键词： time-resolved luminescence imaging,aggregation-induced delayed fluorescence enhancement,thermally activated delayed fluorescence,mitochondria-specific imaging
更新于2025-09-23 15:22:29
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A fast scheme for renal microvascular perfusion functional imaging: Assessed by an imaging quality evaluation model
摘要： Purpose: This study aimed to develop a fast scheme of multiparametric perfusion functional imaging (PFI) based on dynamic contrast-enhanced ultrasound (DCEUS) for assessing renal microvascular hemodynamics. Method: The flow process in the DCEUS-based PFI was modified step-by-step to improve its operational efficiency, which was validated through in vivo renal perfusion experiments. A multiparametric model with a comprehensive coefficient of imaging quality (CIQ) was then built on four terms of the average information entropy, contrast, gray, and noise coefficient of PFIs to evaluate the sacrifice of imaging quality during modifications of DCEUS-based PFI. Results: The multiparametric model successfully evaluated modifications of DCEUS-based PFI from multiple perspectives (R2 = 0.73, P < 0.01). Compared with the raw scheme in the renal sagittal and coronal planes, the fast PFI scheme significantly improved its operational efficiency by 62.82 ± 1.07% (P < 0.01) and the nine PFIs simultaneously maintained a similar CIQ of 0.26 ± 0.06. Conclusions: The inhomogeneous hemodynamic distributions with a ring-like feature in the renal microvasculature were accurately and efficiently characterized by the fast PFI scheme. The fast PFI scheme can be applied for early diagnosis, follow-up evaluation and monitoring treatment of chronic kidney disease.
关键词： modification,coefficient of imaging quality,perfusion functional imaging,multiparametric model,dynamic contrast-enhanced ultrasound
更新于2025-09-23 15:22:29
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Tumor recognition of peanut agglutinin-immobilized fluorescent nanospheres in biopsied human tissues
摘要： We are investigating an imaging agent for early detection of colorectal cancer. The agent, named the nanobeacon, is coumarin 6-encapsulated polystyrene nanospheres whose surfaces are covered with poly(N-vinylacetamide) and peanut agglutinin that reduces non-specific interactions with the normal mucosa and exhibits high affinity for terminal sugars of the Thomsen-Friedenreich antigen, which is expressed cancer-specifically on the mucosa, respectively. We expect that cancer can be diagnosed by detecting illumination of intracolonically administered nanobeacon on the mucosal surface. In the present study, biopsied human tissues were used to evaluate the potential use of the nanobeacon in the clinic. Prior to the clinical study, diagnostic capabilities of the nanobeacon for detection of colorectal cancer were validated using 20 production batches whose characteristics were fine-tuned chemically for the purpose. Ex vivo imaging studies on 66 normal and 69 cancer tissues removed from the colons of normal and orthotopic mouse models of human colorectal cancer, respectively, demonstrated that the nanobeacon detected colorectal cancer with excellent capabilities whose rates of true and false positives were 91% and 5%, respectively. In the clinical study, normal and tumor tissues on the large intestinal mucosa were biopsied endoscopically from 11 patients with colorectal tumors. Histological evaluation revealed that 9 patients suffered from cancer and the rest had adenoma. Mean fluorescence intensities of tumor tissues treated with the nanobeacon were significantly higher than those of the corresponding normal tissues. Correlation of magnitude relation of the intensity in individuals was observed in cancer patients with a high probability (89%); however, the probability reduced to 50% in adenoma patients. There was a reasonable likelihood for diagnosis of colorectal cancer by the nanobeacon applied to the mucosa of the large intestine.
关键词： Colorectal cancer,Diagnostic agent,Optical imaging,Peanut agglutinin,Biomarker imaging,Nanosphere,Thomsen-Friedenreich antigen
更新于2025-09-23 15:22:29
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Assessment of diabetic teleretinal imaging program at the Portland Department of Veterans Affairs Medical Center
摘要： We conducted a retrospective chart review of 200 diabetic patients who had teleretinal imaging performed between January 1, 2010, and January 1, 2011, at Portland Department of Veterans Affairs (VA) Medical Center outpatient clinics to assess the effectiveness of the diabetic teleretinal imaging program. Twenty patients (10%) had diabetic retinopathy. Ninety percent of the available teleretinal imaging studies were of adequate quality for interpretation. In accordance with local VA policy at that time, all teleretinal imaging patients should have been referred for a dilated retinal examination the following year. Image readers referred 97.5% of the patients to eye clinics for subsequent eye examinations, but the imagers scheduled appointments for only 80% of these patients. The redundancy rate, i.e., patients who had an eye examination within the past 6 mo, was 11%; the duplicate recall rate, i.e., patients who had a second teleretinal imaging performed within 1 yr of the eye examination, was 37%. Rates of timely diabetic eye examinations at clinics with teleretinal imaging programs, particularly when teleretinal imaging and eye clinics were colocated at the same community-based outpatient clinic, were higher than at those without a teleretinal imaging program. We concluded that the Portland VA Medical Center's teleretinal imaging program was successful in increasing the screening rate for diabetic retinopathy.
关键词： teleretinal imaging program,diabetes mellitus,dilated eye examination,diabetic retinal examination,primary care,diabetic retinopathy,outpatient clinic,screening,teleretinal imaging,telehealth
更新于2025-09-23 15:22:29
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A novel bioreactor for combined magnetic resonance spectroscopy and optical imaging of metabolism in 3D cell cultures
摘要： Purpose: Fluorescence lifetime imaging microscopy (FLIM) of endogenous fluorescent metabolites permits the measurement of cellular metabolism in cell, tissue and animal models. In parallel, magnetic resonance spectroscopy (MRS) of dynamic nuclear (hyper)polarized 13C‐pyruvate enables measurement of metabolism at larger in vivo scales. Presented here are the design and initial application of a bioreactor that connects these 2 metabolic imaging modalities in vitro, using 3D cell cultures. Methods: The model fitting for FLIM data analysis and the theory behind a model for the diffusion of pyruvate into a collagen gel are detailed. The device is MRI‐compatible, including an optical window, a temperature control system and an injection port for the introduction of contrast agents. Three‐dimensional printing, computer numerical control machining and laser cutting were used to fabricate custom parts. Results: Performance of the bioreactor is demonstrated for 4 T1 murine breast cancer cells under glucose deprivation. Mean nicotinamide adenine dinucleotide (NADH) fluorescence lifetimes were 10% longer and hyperpolarized 13C lactate:pyruvate (Lac:Pyr) ratios were 60% lower for glucose‐deprived 4 T1 cells compared to 4 T1 cells in normal medium. Looking at the individual components of the NADH fluorescent lifetime, τ1 (free NADH) showed no significant change, while τ2 (bound NADH) showed a significant increase, suggesting that the increase in mean lifetime was due to a change in bound NADH. Conclusion: A novel bioreactor that is compatible with, and can exploit the benefits of, both FLIM and 13C MRS in 3D cell cultures for studies of cell metabolism has been designed and applied.
关键词： multimodal,optical imaging,bioreactor,magnetic resonance spectroscopy (MRS),nicotinamide adenine dinucleotide (NADH),metabolism,fluorescence lifetime imaging (FLIM),lactate production
更新于2025-09-23 15:22:29
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[IEEE 2018 International Conference on Intelligent Informatics and Biomedical Sciences (ICIIBMS) - Bangkok (2018.10.21-2018.10.24)] 2018 International Conference on Intelligent Informatics and Biomedical Sciences (ICIIBMS) - A Novel Tumor Imaging Agent, Tc-99m and Fluorescence Labeled Gastrin-Releasing Peptide Analogues
摘要： Statement of the Problem: A variety of imaging probes have been developed for different molecular targets. The gastrin-releasing peptide (GRP) analogues (GRP, GRP18-27 and GRP21-27) were investigated vigorously as a targeting peptide for tumor, however, the cancer targeting abilities of these GRP analogues had not been compared head-to-head. Direct comparison of characteristics of these analogues will provide a useful information for the design of molecular imaging agent associated with GRP and an insight within the mechanism of tumor targeting using GRP analogues. Approach: In the present study, we developed Tc-99m and fluorescence (carboxytetramethylrhodamine, TAMRA) labeled GRP analogues containing three different peptides (TAMRA-GHEG-ECG-GRP, TAMRA-GHEG-ECG-GRP18-27 and TAMRA-GHEG-ECG-GRP21-27) to target the tumor cells and compared the tumor targeting abilities using in vitro and in vivo experiments. Peptides were synthesized using Fmoc solid-phase peptide synthesis. Radiolabeling of peptides with Tc-99m was done using ligand exchange via tartrate. Binding affinity and in vitro cellular uptake studies were performed. Gamma camera imaging study was performed in murine models with PC-3 tumors. The average counts per pixel within the ROIs were measured and target-to-non-target ratios were calculated. Results: After radiolabeling procedures with Tc-99m, Tc-99m labeled peptides were prepared in high yield (>96%). Tc-99m TAMRA-GHEG-ECG-GRP (Kd = 7.9 ± 2.7 nM) showed highest binding affinity for PC-3 tumor cells and Tc-99m TAMRA-GHEG-ECG-GRP18-27 (Kd = 12.6 ± 3.6 nM) showed relatively low binding affinity. Confocal microscopy images of PC-3 cells incubated with TAMRA-GHEG-ECG-GRP and TAMRA-GHEG-ECG-GRP21-27 showed strong fluorescence in the cytoplasm. Gamma camera imaging revealed substantial uptake of Tc-99m TAMRA-GHEG-ECG-GRP21-27 in tumors. Conclusion: We developed three Tc-99m and TAMRA labeled GRP analogues as a molecular imaging agent for targeting tumor. In vitro studies demonstrated substantial binding affinity and cellular uptake of TAMRA-GHEG-ECG-GRP and TAMRA-GHEG-ECG-GRP21-27. In contrast, in vivo gamma imaging study revealed that only Tc-99m TAMRA-GHEG-ECG-GRP21-27 was significantly accumulated in the tumor tissue. Taken together, the present study suggest that 7-mer peptide, GRP21-27 is the best surrogate as a targeting ligand for tumor imaging.
关键词： Gastrin-releasing peptide,Bombesin,Tc-99m,TAMRA,Multimodal imaging
更新于2025-09-23 15:22:29
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[IEEE 2018 International Conference on Intelligent Informatics and Biomedical Sciences (ICIIBMS) - Bangkok (2018.10.21-2018.10.24)] 2018 International Conference on Intelligent Informatics and Biomedical Sciences (ICIIBMS) - Computational Study of Frozen Tissue Melanoma Imagining at Terahertz Frequencies
摘要： Terahertz radiation is highly absorbed by liquid water, with less than 0.0001% of the signal surviving to a depth of 1.0 millimeter at 0.45 terahertz, limiting the potential for imaging of human tissues. On the other hand, 90% of the terahertz signal survives in ice in the 0.1 to 1.0 terahertz band, opening the possibility of in-vivo imaging of skin lesions, particularly melanomas, to a depth of 5.0 millimeters by first freezing the skin in situ. Computational modelling of THz-frozen skin imaging indicates that contrast exists to differentiate melanomas from normal frozen skin on the basis of water content alone. If the melanin content of melanomas is a significant absorber of terahertz radiation, then melanin becomes the main contrast element. The modelling results justify the further exploration of the imaging technique with the study of ex-vivo frozen melanoma samples before progressing to in-vivo clinical trials.
关键词： terahertz,melanoma,skin,freezing,imaging
更新于2025-09-23 15:22:29