scholarly journals Label-Free Macroscopic Fluorescence Lifetime Imaging of Brain Tumors

2021 ◽  
Vol 11 ◽  
Author(s):  
Maria Lukina ◽  
Konstantin Yashin ◽  
Elena E. Kiseleva ◽  
Anna Alekseeva ◽  
Varvara Dudenkova ◽  
...  
Keyword(s):  
White Matter ◽  
Brain Tumors ◽  
Fluorescence Lifetime ◽  
Fluorescence Lifetime Imaging ◽  
Label Free ◽  
Time Resolved ◽  
Lifetime Imaging ◽  
Endogenous Fluorophores ◽  
Optical Markers ◽  
Brain Tissues

Advanced stage glioma is the most aggressive form of malignant brain tumors with a short survival time. Real-time pathology assisted, or image guided surgical procedures that eliminate tumors promise to improve the clinical outcome and prolong the lives of patients. Our work is focused on the development of a rapid and sensitive assay for intraoperative diagnostics of glioma and identification of optical markers essential for differentiation between tumors and healthy brain tissues. We utilized fluorescence lifetime imaging (FLIM) of endogenous fluorophores related to metabolism of the glioma from freshly excised brains tissues. Macroscopic time-resolved fluorescence images of three intracranial animal glioma models and surgical samples of patients’ glioblastoma together with the white matter have been collected. Several established and new algorithms were applied to identify the imaging markers of the tumors. We found that fluorescence lifetime parameters characteristic of the glioma provided background for differentiation between the tumors and intact brain tissues. All three rat tumor models demonstrated substantial differences between the malignant and normal tissue. Similarly, tumors from patients demonstrated statistically significant differences from the peritumoral white matter without infiltration. While the data and the analysis presented in this paper are preliminary and further investigation with a larger number of samples is required, the proposed approach based on the macroscopic FLIM has a high potential for diagnostics of glioma and evaluation of the surgical margins of gliomas.

scholarly journals Label-free sensing of cells with fluorescence lifetime imaging: the quest for metabolic heterogeneity

2022 ◽  
Author(s):  
Evgeny A Shirshin ◽  
Marina V Shirmanova ◽  
Alexey V Gayer ◽  
Maria M Lukina ◽  
Elena E Nikonova ◽  
...  
Keyword(s):  
Fluorescence Lifetime ◽  
Fluorescence Decay ◽  
Fluorescence Lifetime Imaging ◽  
Label Free ◽  
Biomedical Sciences ◽  
Lifetime Imaging ◽  
Endogenous Fluorophores ◽  
Novel Approach ◽  
Metabolic Heterogeneity ◽  
Decay Parameters

Molecular, morphological and physiological heterogeneity is the inherent property of cells, which governs differences in their response to external influence. The tumor cells metabolic heterogeneity is of a special interest due to its clinical relevance to the tumor progression and therapeutic outcomes. Rapid, sensitive and non-invasive assessment of metabolic heterogeneity of cells is of a great demand for biomedical sciences. Fluorescence lifetime imaging (FLIM), which is an all-optical technique is an emerging tool for sensing and quantifying cellular metabolism by measuring fluorescence decay parameters (FDPs) of endogenous fluorophores, such as NAD(P)H. To achieve the accurate discrimination between metabolically diverse cellular subpopulations, appropriate approaches to FLIM data collection and analysis are needed. In this report, the unique capability of FLIM to attain the overarching goal of discriminating metabolic heterogeneity has been demonstrated. This has been achieved using a novel approach to data analysis based on the non-parametric analysis, which revealed a much better sensitivity to the presence of metabolically distinct subpopulations as compare more traditional approaches of FLIM measurements and analysis. The new approach was further validated for imaging cultured cancer cells treated with chemotherapy. Those results pave the way for an accurate detection and quantification of cellular metabolic heterogeneity using FLIM, which will be valuable for assessing therapeutic vulnerabilities and predicting clinical outcomes.

scholarly journals The biochemical resolving power of fluorescence lifetime imaging

2021 ◽  
Author(s):  
Andrew L. Trinh ◽  
Alessandro Esposito
Keyword(s):  
Fluorescence Lifetime ◽  
Resolving Power ◽  
Fluorescence Lifetime Imaging ◽  
Time Resolved ◽  
Instrument Response Function ◽  
Lifetime Imaging ◽  
Use Of Time ◽  
Single Living Cells ◽  
Microscopy Techniques

AbstractA deeper understanding of spatial resolution in microscopy fostered a technological revolution that is now permitting us to investigate the structure of the cell with nanometer resolution. Although fluorescence microscopy techniques enable scientists to investigate both the structure and biochemistry of the cell, the biochemical resolving power of a microscope is a physical quantity that is not well-defined or studied. To overcome this limitation, we carried out a theoretical investigation of the biochemical resolving power in fluorescence lifetime imaging microscopy, one of the most effective tools to investigate biochemistry in single living cells. With the theoretical analysis of information theory and Monte Carlo simulations, we describe how the ‘biochemical resolving power’ in time-resolved sensing depends on instrument specifications. We unravel common misunderstandings on the role of the instrument response function and provide theoretical insights that have significant practical implications in the design and use of time-resolved instrumentation.

scholarly journals Macroscopic fluorescence-lifetime imaging of NADH and protoporphyrin IX improves the detection and grading of 5-aminolevulinic acid-stained brain tumors

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mikael T. Erkkilä ◽  
David Reichert ◽  
Johanna Gesperger ◽  
Barbara Kiesel ◽  
Thomas Roetzer ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Brain Tumors ◽  
Fluorescence Lifetime ◽  
Tumor Tissue ◽  
Aminolevulinic Acid ◽  
Protoporphyrin Ix ◽  
Low Grade ◽  
Wide Field ◽  
Fluorescence Lifetime Imaging ◽  
Lifetime Imaging

AbstractMaximal safe tumor resection remains the key prognostic factor for improved prognosis in brain tumor patients. Despite 5-aminolevulinic acid-based fluorescence guidance the neurosurgeon is, however, not able to visualize most low-grade gliomas (LGG) and infiltration zone of high-grade gliomas (HGG). To overcome the need for a more sensitive visualization, we investigated the potential of macroscopic, wide-field fluorescence lifetime imaging of nicotinamide adenine dinucleotide (NADH) and protoporphyrin IX (PPIX) in selected human brain tumors. For future intraoperative use, the imaging system offered a square field of view of 11 mm at 250 mm free working distance. We performed imaging of tumor tissue ex vivo, including LGG and HGG as well as brain metastases obtained from 21 patients undergoing fluorescence-guided surgery. Half of all samples showed visible fluorescence during surgery, which was associated with significant increase in PPIX fluorescence lifetime. While the PPIX lifetime was significantly different between specific tumor tissue types, the NADH lifetimes did not differ significantly among them. However, mainly necrotic areas exhibited significantly lower NADH lifetimes compared to compact tumor in HGG. Our pilot study indicates that combined fluorescence lifetime imaging of NADH/PPIX represents a sensitive tool to visualize brain tumor tissue not detectable with conventional 5-ALA fluorescence.

A Time-Resolved Four-Tap Lock-In Pixel CMOS Image Sensor for Real-Time Fluorescence Lifetime Imaging Microscopy

2018 ◽  
Vol 53 (8) ◽  
pp. 2319-2330 ◽  
Author(s):  
Min-Woong Seo ◽  
Yuya Shirakawa ◽  
Yoshimasa Kawata ◽  
Keiichiro Kagawa ◽  
Keita Yasutomi ◽  
...  
Keyword(s):  
Real Time ◽  
Fluorescence Lifetime ◽  
Cmos Image Sensor ◽  
Image Sensor ◽  
Fluorescence Lifetime Imaging Microscopy ◽  
Fluorescence Lifetime Imaging ◽  
Time Resolved ◽  
Lifetime Imaging ◽  
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