Fluorescence Molecular Tomography Research Articles

Fluorescence-guided tumor visualization of colorectal cancer using tumor-initiating probe yellow in preclinical models

Fluorescence-guided surgery has emerged as an innovative technique with promising applications in the treatment of various tumors, including colon cancer. Tumor-initiating probe yellow (TiY) has been discovered for identifying tumorigenic cells by unbiased phenotypic screening with thousands of diversity-oriented fluorescence library (DOFL) compounds in a patient-derived lung cancer cell model. This study demonstrated the clinical feasibility of TiY for tumor-specific fluorescence imaging in the tissues of patients with colorectal cancer (CRC). To evaluate the efficacy of TiY in tumor imaging, surgical specimens were obtained, consisting of 36 tissues from 18 patients with CRC, for ex vivo molecular fluorescence imaging, histology, and immunohistochemistry. Orthotopic and chemically induced CRC mice models were administered TiY topically, and distinct tumor lesions were observed in 10 min by real-time fluorescence colonoscopy and ex vivo imaging. In a hepatic metastasis mouse model using splenic injection, TiY accumulation was detected in metastatic liver lesions through fluorescence imaging. Correlation analysis between TiY intensity and protein expression, assessed via immunohistochemistry and Western blotting, revealed a positive correlation between TiY and vimentin and Zeb1, which are known as epithelial–mesenchymal transition (EMT) markers of cancers. A comparative analysis of TiY with other FDA-approved fluorescence probes such as ICG revealed greater quantitative differences in TiY fluorescence intensity between tumor and normal tissues than those observed with ICG. Altogether, these results demonstrated that TiY has a strong potential for visualizing CRC by fluorescence imaging in various preclinical models, which can be further translated for clinical use such as fluorescence-guided surgery. Furthermore, our data indicate that TiY is preferentially uptaken by cells with EMT induction and progression, and overexpressing vimentin and Zeb1 in patients with CRC.

Intraoperative Guidance of Pancreatic Cancer Resection Using a Toll-like Receptor 2-Targeted Fluorescence Molecular Imaging Agent.

Human TLR2 is broadly expressed among pancreatic adenocarcinomas, and the highly specific TLR2L-800 fluorescence molecular imaging agent has potential for use in fluorescence-guided surgery to increase R0 margins and improve patient survival.

Sparse-Laplace hybrid graph manifold method for fluorescence molecular tomography

Objective.Fluorescence molecular tomography (FMT) holds promise for early tumor detection by mapping fluorescent agents in three dimensions non-invasively with low cost. However, since ill-posedness and ill-condition due to strong scattering effects in biotissues and limited measurable data, current FMT reconstruction is still up against unsatisfactory accuracy, including location prediction and morphological preservation.Approach.To strike the above challenges, we propose a novel Sparse-Laplace hybrid graph manifold (SLHGM) model. This model integrates a hybrid Laplace norm-based graph manifold learning term, facilitating a trade-off between sparsity and preservation of morphological features. To address the non-convexity of the hybrid objective function, a fixed-point equation is designed, which employs two successive resolvent operators and a forward operator to find a converged solution.Main results.Through numerical simulations andin vivoexperiments, we demonstrate that the SLHGM model achieves an improved performance in providing accurate spatial localization while preserving morphological details.Significance.Our findings suggest that the SLHGM model has the potential to advance the application of FMT in biological research, not only in simulation but also inin vivostudies.

Progression in Near-Infrared Fluorescence Imaging Technology for Lung Cancer Management.

Lung cancer is a major threat to human health and a leading cause of death. Accurate localization of tumors in vivo is crucial for subsequent treatment. In recent years, fluorescent imaging technology has become a focal point in tumor diagnosis and treatment due to its high sensitivity, strong selectivity, non-invasiveness, and multifunctionality. Molecular probes-based fluorescent imaging not only enables real-time in vivo imaging through fluorescence signals but also integrates therapeutic functions, drug screening, and efficacy monitoring to facilitate comprehensive diagnosis and treatment. Among them, near-infrared (NIR) fluorescence imaging is particularly prominent due to its improved in vivo imaging effect. This trend toward multifunctionality is a significant aspect of the future advancement of fluorescent imaging technology. In the past years, great progress has been made in the field of NIR fluorescence imaging for lung cancer management, as well as the emergence of new problems and challenges. This paper generally summarizes the application of NIR fluorescence imaging technology in these areas in the past five years, including the design, detection principles, and clinical applications, with the aim of advancing more efficient NIR fluorescence imaging technologies to enhance the accuracy of tumor diagnosis and treatment.

Novel anti-CEA affibody for rapid tumor-targeting and molecular imaging diagnosis in mice bearing gastrointestinal cancer cell lines.

Gastrointestinal cancer is a common malignant tumor with a high incidence worldwide. Despite continuous improvements in diagnosis and treatment strategies, the overall prognosis of gastrointestinal tumors remains poor. Carcinoembryonic antigen (CEA) is highly expressed in various types of cancers, especially in gastrointestinal cancers, making it a potential target for therapeutic intervention. Therefore, the expression of CEA can be used as an indication of the existence of tumors, chosen as a target for molecular imaging diagnosis, and effectively utilized in the targeted therapy of gastrointestinal cancers. In this study, we report the selection and characterization of affibody molecules (ZCEA539, ZCEA546, and ZCEA919) specific to the CEA protein. Their ability to bind to recombinant and native CEA protein has been confirmed by surface plasmon resonance (SPR), immunofluorescence, and immunohistochemistry assays. Furthermore, Dylight755-labeled ZCEA affibody showed accumulation within the tumor site 1 h post injection and was continuously enhanced for 4 h. The Dylight755-labeled ZCEA affibody exhibited high tumor-targeting specificity in CEA+ xenograft-bearing mice and possesses promising characteristics for tumor-targeting imaging. Overall, our results suggest the potential use of ZCEA affibodies as fluorescent molecular imaging probes for detecting CEA expression in gastrointestinal cancer.

Pre-clinical study of IR808 dye for cervical cancer in vitro and in vivo imaging.

There is an urgent need for improved methods for early screening and rapid diagnosis of cervical cancer since current conventional screening methods are plagued by operator subjectivity and unnecessary biopsies. IR808 is a tumour-targeting near-infrared (NIR) fluorescent dye that permits NIR imaging without the requirement of chemical conjugation. Our study investigates an IR808-based strategy for real-time monitoring of the cervix in vivo and rapid assessment of cervical specimens in vitro. We investigated the uptake of IR808 in vitro using normal cervical epithelial cells and three cervical cancer cell lines. The biodistribution of IR808 was examined in vivo via intravenous injection into tumour-bearing mice. Additionally, in vitro tissues were stained with IR808 to simulate the identification of cervical tumors in the clinical setting. Biocompatibility of the dye in both cellular and animal models was also examined. IR808 exhibited significant tumour-to-background ratios in fluorescence molecular imaging of in vivo tumors in nude mice. The application of NIR fluorescent dye IR808 in specific imaging screening, safe and non-invasive real-time monitoring, and rapid identification of cervical tumors from tissue specimens is expected to improve current screening methods for cervical cancer.

CD24-Targeted NIR-II Fluorescence Imaging Enables Early Detection of Colorectal Neoplasia.

Colorectal cancer (CRC) continues to be a major health issue even though screening methods have facilitated early detection. Despite the high sensitivity of white-light colonoscopy, it frequently overlooks invasive flat or depressed lesions, which can lead to the development of larger, advanced tumors. Fluorescence molecular imaging (FMI) offers a promising approach for early tumor detection by targeting specific molecular characteristics of lesions. CD24 is upregulated during the adenoma-to-CRC transition, providing a potential target for FMI. Here, we developed a second near-infrared window (NIR-II) fluorescent probe with a high affinity for CD24 and evaluated its efficacy and targeting ability in cellular models, murine models, and clinical samples of CRC. CD24 expression was elevated in 76% of adenomas and 80% of CRCs. In a colitis-associated cancer mouse model, NIR-II imaging with the CD24-targeted probe achieved a significantly higher tumor-to-background ratio compared to conventional NIR-I imaging. The probe demonstrated exceptional sensitivity (92%) and specificity (92%) for detecting CRC, including small lesions less than 1 mm in size. This led to the identification of precancerous lesions missed by white-light detection and lesions missed by NIR-I imaging. Moreover, ex vivo human tissue incubation with the probe supported the potential for intraprocedural lesion identification via topical probe application during colonoscopy. In conclusion, this study successfully demonstrates the potential of CD24-targeted NIR-II imaging for identifying colorectal neoplasia, highlighting its significance for early CRC detection in the gastrointestinal tract.

Reduction Accelerated Adaptive Step‐Size FISTA Based Smooth‐Lasso Regularization for Fluorescence Molecular Tomography Reconstruction

ABSTRACTIn this paper, a reduced accelerated adaptive fast iterative shrinkage threshold algorithm based on Smooth‐Lasso regularization (SL‐RAFISTA‐BB) is proposed for fluorescence molecular tomography (FMT) 3D reconstruction. This method uses the Smooth‐Lasso regularization to fuse the group sparse prior information which can balance the relationship between the sparsity and smoothness of the solution, simplifying the process of calculation. In particular, the convergence speed of the FISTA is improved by introducing a reduction strategy and Barzilai‐Borwein variable step size factor, and constructing a continuation strategy to reduce computing costs and the number of iterations. The experimental results show that the proposed algorithm not only accelerates the convergence speed of the iterative algorithm, but also improves the positioning accuracy of the tumor target, alleviates the over‐sparse or over‐smooth phenomenon of the reconstructed target, and clearly outlines the boundary information of the tumor target. We hope that this method can promote the development of optical molecular tomography.

Dual and Multi-Target Cone-Beam X-ray Luminescence Computed Tomography Based on the DeepCB-XLCT Network.

Emerging as a hybrid imaging modality, cone-beam X-ray luminescence computed tomography (CB-XLCT) has been developed using X-ray-excitable nanoparticles. In contrast to conventional bio-optical imaging techniques like bioluminescence tomography (BLT) and fluorescence molecular tomography (FMT), CB-XLCT offers the advantage of greater imaging depth while significantly reducing interference from autofluorescence and background fluorescence, owing to its utilization of X-ray-excited nanoparticles. However, due to the intricate excitation process and extensive light scattering within biological tissues, the inverse problem of CB-XLCT is fundamentally ill-conditioned. An end-to-end three-dimensional deep encoder-decoder network, termed DeepCB-XLCT, is introduced to improve the quality of CB-XLCT reconstructions. This network directly establishes a nonlinear mapping between the distribution of internal X-ray-excitable nanoparticles and the corresponding boundary fluorescent signals. To improve the fidelity of target shape restoration, the structural similarity loss (SSIM) was incorporated into the objective function of the DeepCB-XLCT network. Additionally, a loss term specifically for target regions was introduced to improve the network's emphasis on the areas of interest. As a result, the inaccuracies in reconstruction caused by the simplified linear model used in conventional methods can be effectively minimized by the proposed DeepCB-XLCT method. Numerical simulations, phantom experiments, and in vivo experiments with two targets were performed, revealing that the DeepCB-XLCT network enhances reconstruction accuracy regarding contrast-to-noise ratio and shape similarity when compared to traditional methods. In addition, the findings from the XLCT tomographic images involving three targets demonstrate its potential for multi-target CB-XLCT imaging.

Multispectral fluorescence imaging of EGFR and PD-L1 for precision detection of oral squamous cell carcinoma: a preclinical and clinical study

BackgroundEarly detection and treatment are effective methods for the management of oral squamous cell carcinoma (OSCC), which can be facilitated by the detection of tumor-specific OSCC biomarkers. The epidermal growth factor receptor (EGFR) and programmed death-ligand 1 (PD-L1) are important therapeutic targets for OSCC. Multispectral fluorescence molecular imaging (FMI) can facilitate the detection of tumor multitarget expression with high sensitivity and safety. Hence, we developed Nimotuzumab-ICG and Atezolizumab-Cy5.5 imaging probes, in combination with multispectral FMI, to sensitively and noninvasively identify EGFR and PD-L1 expression for the detection and comprehensive treatment of OSCC.MethodsThe expression of EGFR and PD-L1 was analyzed using bioinformatics data sources and specimens. Nimotuzumab-ICG and Atezolizumab-Cy5.5 imaging probes were developed and tested on preclinical OSCC cell line and orthotopic OSCC mouse model, fresh OSCC patients’ biopsied samples, and further clinical mouthwash trials were conducted in OSCC patients.ResultsEGFR and PD-L1 were specifically expressed in human OSCC cell lines and tumor xenografts. Nimotuzumab-ICG and Atezolizumab-Cy5.5 imaging probes can specifically target to the tumor sites in an in situ human OSCC mouse model with good safety. The detection sensitivity and specificity of Nimotuzumab-ICG in patients were 96.4% and 100%, and 95.2% and 88.9% for Atezolizumab-Cy5.5.ConclusionsEGFR and PD-L1 are highly expressed in OSCC, the combination of which is important for a precise prognosis of OSCC. EGFR and PD-L1 expression can be sensitively detected using the newly synthesized multispectral fluorescence imaging probes Nimotuzumab-ICG and Atezolizumab-Cy5.5, which can facilitate the sensitive and specific detection of OSCC and improve treatment outcomes.Trial registrationChinese Clinical Trial Registry, ChiCTR2100045738. Registered 23 April 2021, https://www.chictr.org.cn/bin/project/edit?pid=125220

Fluorescence separation based on Spatiotemporal Gaussian Mixture Model for dynamic fluorescence molecular tomography

Fluorescence separation based on Spatiotemporal Gaussian Mixture Model for dynamic fluorescence molecular tomography

Fluorescently labelled vedolizumab to visualise drug distribution and mucosal target cells in inflammatory bowel disease

ObjectiveImproving patient selection and development of biological therapies such as vedolizumab in IBD requires a thorough understanding of the mechanism of action and target binding, thereby providing individualised treatment strategies....

Ex vivo optical coherence tomography combined with near infrared targeted fluorescence: towards in-vivo esophageal cancer detection.

Early detection of (pre)malignant esophageal lesions is critical to improve esophageal cancer morbidity and mortality rates. In patients with advanced esophageal adenocarcinoma (EAC) who undergo neoadjuvant chemoradiation therapy, the efficacy of therapy could be optimized and unnecessary surgery prevented by the reliable assessment of residual tumors after therapy. Optical coherence tomography (OCT) provides structural images at a (sub)-cellular level and has the potential to visualize morphological changes in tissue. However, OCT lacks molecular imaging contrast, a feature that enables the study of biological processes at a cellular level and can enhance esophageal cancer diagnostic accuracy. We combined OCT with near-infrared fluorescence molecular imaging using fluorescently labelled antibodies (immuno-OCT). The main goal of this proof of principle study is to investigate the feasibility of immuno-OCT for esophageal cancer imaging. We aim to assess whether the sensitivity of our immuno-OCT device is sufficient to detect the tracer uptake using an imaging dose (∼100 times smaller than a dose with therapeutic effects) of a targeted fluorescent agent. The feasibility of immuno-OCT was demonstrated ex-vivo on dysplastic lesions resected from Barrett's patients and on esophageal specimens resected from patients with advanced EAC, who were respectively topically and intravenously administrated with the tracer bevacizumab-800CW. The detection sensitivity of our system (0.3 nM) is sufficient to detect increased tracer uptake with micrometer resolution using an imaging dose of labelled antibodies. Moreover, the absence of layered structures that are typical of normal esophageal tissue observed in OCT images of dysplastic/malignant esophageal lesions may further aid their detection. Based on our preliminary results, immuno-OCT could improve the detection of dysplastic esophageal lesions.

Integration of photomagnetic bimodal imaging to monitor an autogenous exosome loaded platform: unveiling strong targeted retention effects for guiding the photothermal and magnetothermal therapy in a mouse prostate cancer model

BackgroundProstate cancer (PCa) is the most prevalent cancer among males, emphasizing the critical need for precise diagnosis and treatment to enhance patient prognosis. Recent studies have extensively utilized urine exosomes from patients with cancer for targeted delivery. This study aimed to employ highly sensitive magnetic particle imaging (MPI) and fluorescence molecular imaging (FMI) to monitor the targeted delivery of an exosome-loaded platform at the tumour site, offering insights into a potential combined photothermal and magnetic thermal therapy regime for PCa.ResultsMPI and FMI were utilized to monitor the in vivo retention performance of exosomes in a prostate tumour mouse model. The exosome-loaded platform exhibited robust homologous targeting ability during imaging (SPIONs@EXO-Dye:66·48%±3·85%; Dye-SPIONs: 34·57%±7·55%, **P<0·01), as verified by in vitro imaging and in vitro tissue Prussian blue staining.ConclusionsThe experimental data underscore the feasibility of using MPI for in vivo PCa imaging. Furthermore, the exosome-loaded platform may contribute to the precise diagnosis and treatment of PCa.Graphical

Near-infrared II fluorescence-guided glioblastoma surgery targeting monocarboxylate transporter 4 combined with photothermal therapy

Surgery is crucial for glioma treatment, but achieving complete tumour removal remains challenging. We evaluated the effectiveness of a probe targeting monocarboxylate transporter 4 (MCT4) in recognising gliomas, and of near-infrared window II (NIR-II) fluorescent molecular imaging and photothermal therapy as treatment strategies. We combined an MCT4-specific monoclonal antibody with indocyanine green to create the probe. An orthotopic mouse model and a transwell model were used to evaluate its ability to guide tumour resection using NIR-II fluorescence and to penetrate the blood-brain barrier (BBB), respectively. A subcutaneous tumour model was established to confirm photothermal therapy efficacy. Probe specificity was assessed in brain tissue from mice and humans. Finally, probe effectiveness in photothermal therapy was investigated. MCT4 was differentially expressed in tumour and normal brain tissue. The designed probe exhibited precise tumour targeting. Tumour imaging was precise, with a signal-to-background (SBR) ratio of 2.8. Residual tumour cells were absent from brain tissue postoperatively (SBR: 6.3). The probe exhibited robust penetration of the BBB. Moreover, the probe increased the tumour temperature to 50°C within 5min of laser excitation. Photothermal therapy significantly reduced tumour volume and extended survival time in mice without damage to vital organs. These findings highlight the potential efficacy of our probe for fluorescence-guided surgery and therapeutic interventions. Jilin Province Department of Science and Technology (20200403079SF), Department of Finance (2021SCZ06) and Development and Reform Commission (20200601002JC); National Natural Science Foundation of China (92059207, 92359301, 62027901, 81930053, 81227901, U21A20386); and CAS Youth Interdisciplinary Team (JCTD-2021-08).

Enhancing precision in colorectal cancer surgery: development of an LGR5-targeting RSPO1 peptide mimetic as a contrast agent for intraoperative fluorescence molecular imaging

ABSTRACT Colorectal cancer (CRC) is the third most common cancer worldwide. In the United States alone, CRC was responsible for approximately 52,550 deaths in 2023, with an estimated 153,020 new cases. CRC presents with synchronous peritoneal spread in 5–10% of patients, and up to 20–50% of patients with recurrent disease will develop metachronous colorectal cancer peritoneal metastatic (CRC-PM) disease. Eradication of the tumor, tumor margins and microscopic residual disease is paramount, as microscopic residual disease is associated with local recurrences, with 5-year survival rates of less than 35%. The success of resection and reduction of residual disease depends on the accuracy with which cancer cells and normal tissue can be intra-operatively distinguished. Fluorescence Molecular Imaging (IFMI) and tumor-targeted contrast agents represent a promising approach for intraoperative detection and surgical intervention. Proper target selection, the development of scalable imaging agents and enhanced real-time tumor and tumor microenvironment imaging are critical to enabling enhanced surgical resection. LGR5 (leucine-rich repeat-containing G-protein-coupled receptor 5), a colonic crypt stem cell marker and the receptor for the R-spondins (RSPO) in the Wnt signaling pathway, is also expressed on colorectal cancer stem cells (CSC) and on CRC tumors and metastases, suggesting it could be a useful target for imaging of CRC. However, there are numerous diverging reports on the role of LGR5 in CRC therapy and outcomes. Herein, we report on the synthesis and validation of a 37 amino acid RSPO1-mimetic peptide, termed RC18, that was specifically designed to access the R-spondin binding site of LGR5 to potentially be used for interoperative imaging of CRC-PM. The receptor-binding capabilities of the RC18 indicate that direct interactions with LGR5 neither significantly increased LGR5 signaling nor blocked RSPO1 binding and signal transduction, suggesting that the RSPO1-mimetic is functionally inert, making it an attractive contrast agent for intraoperative CRC-PM imaging.

Lanctos 75™ is A Novel Retino-Protective and Neovascular Inhibitor for Diabetic Retinopathy

Diabetic retinopathy (DR) is a significant neurovascular complication driven by abnormal angiogenesis. This study evaluated the efficacy and safety of Lanctos 75™, a proprietary standardized extract of Orthosiphon stamineus leaves (code name C5OSEW5050ESA), as a retinal-protective and anti-neovascular agent in streptozotocin-induced diabetic retinopathy in rats. The safety and neuroprotective properties of Lanctos 75™ were assessed in various in vitro and in vivo models of ischemia-induced neuronal injury. In vitro studies using RGC-5 cells showed that Lanctos 75™ significantly suppressed apoptosis, demonstrating strong cytoprotective effects. In vivo, PanOptic ophthalmoscopic imaging in diabetic rats revealed that Lanctos 75™ protected against retinal damage, inhibiting the development of microaneurysms, hemorrhages, vascular leakage, venous beading, and retinal inflammation. Fluorescence molecular tomography (FMT) imaging further confirmed its protective effect against ischemia-reperfusion injury and related inflammation. Overall, the results suggest that Lanctos 75™, with an effective dose of O. stamineus, holds promise as an adjunct therapy for diabetic retinopathy and other neovascular-related eye conditions.

Generation and Characterization of Novel Pan-Cancer Anti-uPAR Fluorescent Nanobodies as Tools for Image-Guided Surgery.

Fluorescence molecular imaging plays a vital role in image-guided surgery. In this context, the urokinase plasminogen activator receptor (uPAR) is an interesting biomarker enabling the detection and delineation of various tumor types due to its elevated expression on both tumor cells and the tumor microenvironment. In this study, anti-uPAR Nanobodies (Nbs) are generated through llama immunization with human and murine uPAR protein. Extensive in vitro characterization and in vivo testing with radiolabeled variants are conducted to assess their pharmacokinetics and select lead compounds. Subsequently, the selected Nbs are converted into fluorescent agents, and their application for fluorescence-guided surgery is evaluated in various subcutaneous and orthotopic tumor models. The study yields a panel of high-affinity anti-uPAR Nbs, showing specific binding across multiple types of cancer cells in vitro and in vivo. Lead fluorescently-labeled compounds exhibit high tumor uptake with high contrast at 1h after intravenous injection across all assessed uPAR-expressing tumor models, outperforming a non-targeting control Nb. Additionally, rapid and accurate tumor localization and demarcation are demonstrated in an orthotopic human glioma model. Utilizing these Nbs can potentially enhance the precision of surgical tumor resection and, consequently, improve survival rates in the clinic.

Novel Near-Infrared Fluorescent Probe for Hepatocyte Growth Factor in Vivo Imaging in Surgical Navigation of Colorectal Cancer.

Despite recent advancements in colorectal cancer (CRC) treatment, the prognosis remains unfavorable primarily due to high recurrence and liver metastasis rates. Fluorescence molecular imaging technologies, combined with specific probes, have gained prominence in facilitating real-time tumor resection guided by fluorescence. Hepatocyte growth factor (HGF) is overexpressed in CRC, but the advancement of HGF fluorescent probes has been impeded by the absence of effective HGF-targeting small-molecular ligands. Herein, we present the targeted capabilities of the novel V-1-GGGK-MPA probe labeled with a near-infrared fluorescent dye, which targets HGF in CRC. The V-1-GGGK peptide exhibits high specificity and selectivity for HGF-positive in vitro tumor cells and in vivo tumors. Biodistribution analysis of V-1-GGGK-MPA revealed tumor-specific accumulation with low background uptake, yielding signal-to-noise ratio (SNR) values of tumor-to-colorectal >6 in multiple subcutaneous CRC models 12 h postinjection. Quantitative analysis confirmed the probe's high uptake in SW480 and HT29 orthotopic and liver metastatic models, with SNR values of tumor-to-colorectal and -liver being 5.6 ± 0.4, 4.6 ± 0.5, and 2.1 ± 0.3, 2.0 ± 0.5, respectively, enabling precise tumor visualization for surgical navigation. Pathological analysis demonstrated the excellent tumor boundaries discrimination capacity of the V-1-GGGK-MPA probe at the molecular level. With its rapid tumor targeting, sustained tumor retention, and precise tumor boundary delineation, V-1-GGGK-MPA merges as a promising HGF imaging agent, enriching the toolbox of intraoperative navigational fluorescent probes for CRC.

Group sparse-based Taylor expansion method for liver pharmacokinetic parameters imaging of dynamic fluorescence molecular tomography

Objective. Pharmacokinetic parametric images obtained through dynamic fluorescence molecular tomography (DFMT) has ability of capturing dynamic changes in fluorescence concentration, thereby providing three-dimensional metabolic information for applications in biological research and drug development. However, data processing of DFMT is time-consuming, involves a vast amount of data, and the problem itself is ill-posed, which significantly limits the application of pharmacokinetic parametric images reconstruction. In this study, group sparse-based Taylor expansion method is proposed to address these problems. Approach. Firstly, Taylor expansion framework is introduced to reduce time and computational cost. Secondly, group sparsity based on structural prior is introduced to improve reconstruction accuracy. Thirdly, alternating iterative solution based on accelerated gradient descent algorithm is introduced to solve the problem. Main results. Numerical simulation and in vivo experimental results demonstrate that, in comparison to existing methods, the proposed approach significantly enhances reconstruction speed without a degradation of quality, particularly when confronted with background fluorescence interference from other organs. Significance. Our research greatly reduces time and computational cost, providing strong support for real-time monitoring of liver metabolism.