Search results for "Autofluorescence"

A device for multimodal imaging of skin

2013

A compact prototype device for diagnostic imaging of skin has been developed and tested. Polarized LED light at several spectral regions is used for illumination, and round skin spot of diameter 30mm is imaged by a CMOS sensor via crossoriented polarizing filter. Four consecutive imaging series are performed: (1) RGB image at white LED illumination for revealing subcutaneous structures; (2) four spectral images at narrowband LED illumination (450nm, 540nm, 660nm, 940nm) for mapping of the main skin chromophores; (3) video-imaging under green LED illumination for mapping of skin blood perfusion; (4) autofluorescence video-imaging under UV (365nm) LED irradiation for mapping of the skin fluor…

Ion-induced fluorescence imaging of endosomes

2013

Abstract Imaging laboratories at Jyvaskyla and Singapore are collaborating on the development of fluorescence imaging of cytoplasmic endosomes using a combination of proton induced fluorescence (PIF) with direct Scanning Transmission Ion Microscopy (direct-STIM) for sub-cellular structural imaging. A549 lung carcinoma cells were cultivated and stained for epidermal growth factor receptor (EGFR) and receptor α2β1 integrin. In this paper, we demonstrate that cells can be imaged at sub-150 nm resolution using the PIF technique. In addition, the same target cell was imaged at 50 and 25 nm resolution by using proton and He-STIM, respectively. The combination of both techniques offer a powerful t…

High-Resolution Fluorescence Spectra of Airborne Biogenic Secondary Organic Aerosols: Comparisons to Primary Biological Aerosol Particles and Implica…

2021

Aqueous extracts of biogenic secondary organic aerosols (BSOAs) have been found to exhibit fluorescence that may interfere with the laser/light-induced fluorescence (LIF) detection of primary biological aerosol particles (PBAPs). In this study, we quantified the interference of BSOAs to PBAPs by directly measuring airborne BSOA particles, rather than aqueous extracts. BSOAs were generated by the reaction of d-limonene (LIM) or α-pinene (PIN) and ozone (O3) with or without ammonia in a chamber under controlled conditions. With an excitation wavelength of 355 nm, BSOAs exhibited peak emissions at 464–475 nm, while fungal spores exhibited peak emissions at 460–483 nm; the fluorescence intensit…

Diagnosis of oral squamous cell carcinoma and its precursor lesions

2007

Improvement of survival rate and quality of life after treatment of oral squamous cell carcinoma as well as cost reduction requires reliable early diagnosis of the tumor and its precursor lesions. Four different screening methods are primarily employed: toluidine blue staining (visually detected lesions: sensitivity 70-100%, specificity 25-67%), photodynamic diagnosis (sensitivity 94-99%, specificity 60-89%), autofluorescence (no data published so far) and modern oral cytology (sensitivity 80%,specificity 95-100%). Additional analytic procedures such automated image analysis, DNA image cytometry and immunocytochemistry can be used to enhance the low sensitivity of conventional oral cytology…

Autofluorescence Imaging of the Skin Is an Objective Non-Invasive Technique for Diagnosing Pseudoxanthoma Elasticum

2021

Pseudoxanthoma elasticum (PXE) is a rare multisystemic autosomal recessive connective tissue disease. In most cases, skin manifestations of PXE are the first to develop, followed later by severe ocular and cardiovascular complications. In our present study, in addition to dermoscopy, we introduced novel techniques, autofluorescence (AF) and diffuse reflectance (DR) imaging for the assessment of affected skin sites of five PXE patients. PXE-affected skin areas in most skin sites showed a previously observed pattern upon dermoscopic examination. With the novel imaging, PXE-affected skin lesions displayed high AF intensity. During our measurements, significantly higher mean, minimum and maximu…

Combination of Autofluorescence imaging and salivary protoporphyrin in Oral precancerous and cancerous lesions: non-invasive tools

2014

Background: Normal and cancerous tissues have distinct auto-fluorescence properties because of differences in their biophysical and biochemical agents. Scientific evidences related to diagnostic fluorescence imaging for detection of oral precancerous and cancerous lesions are very limited. Objectives: The aim of this study was to find out potential relationships between serum, salivary and tissue protoporphyrin IX ( PX) levels in subjects with or without oral precancerous and cancerous lesions. Also, to find out diagnostic value of fluorescence imaging (VELscope® system, LED Dental Inc., White Rock, B.C.) and salivary protoporphyrin IX (PX) in oral precancerous and cancerous lesions. Furthe…

089 Autofluorescence imaging for non-invasive visualization and quantification of skin lesions of patients with pseudoxanthoma elasticum

2021

Autofluorescence imaging of basal cell carcinoma by smartphone RGB camera

2015

The feasibility of smartphones for in vivo skin autofluorescence imaging has been investigated. Filtered autofluorescence images from the same tissue area were periodically captured by a smartphone RGB camera with subsequent detection of fluorescence intensity decreasing at each image pixel for further imaging the planar distribution of those values. The proposed methodology was tested clinically with 13 basal cell carcinoma and 1 atypical nevus. Several clinical cases and potential future applications of the smartphone-based technique are discussed.

Multispectral, Fluorescent and Photoplethysmographic Imaging for Remote Skin Assessment

2017

Optical tissue imaging has several advantages over the routine clinical imaging methods, including non-invasiveness (does not change the structure of tissues), remote operation (avoids infection) and ability to quantify the tissue condition by means of specific image parameters. Dermatologists and other skin experts need compact (preferably pocket-size), self-sustained and easy-to-use imaging devices. The operational principles and designs of ten portable in-vivo skin imaging prototypes developed at the Biophotonics Laboratory of Institute of Atomic Physics and Spectroscopy, University of Latvia during the recent five years are presented in this paper. Four groups of imaging devices are con…

Estimating the chance of success of archaeometric analyses of bone: UV-induced bone fluorescence compared to histological screening

2011

Abstract For most archaeometric analyses on archaeological bone material, such as the determination of the isotopic composition or genetic approaches, an advanced degree of diagenetic alteration can make designated analysis impossible. Since the lack of a positive signal is mostly seen only after time consuming and cost intensive sample processing, the need for an easy-to-apply screening method that allows a pre-selection of samples containing well-preserved biomolecules is obvious. In this study, we visually determined the UV-induced autofluorescence of 76 horse bone cross-sections, all from prehistoric archaeological sites of varying environmental and chronological background. In order to…