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Optical Methods for Diabetic Foot Ulcer Screening
Published in Andrey V. Dunaev, Valery V. Tuchin, Biomedical Photonics for Diabetes Research, 2023
Robert Bartlett, Gennadi Saiko, Alexandre Yu. Douplik
The ultimate utility of fluorescence imaging is to assist in treatment selection. Studies have shown that fluorescence imaging can prompt changes in the proposed treatment plans, including alterations in antimicrobial prescribing [111], decisions around negative pressure wound therapy [112], and timing of grafting or applications of skin substitutes [113]. It may lead to changes in the treatment plan in as many as 73% of cases.
Small Animal Imaging and Therapy
Published in George C. Kagadis, Nancy L. Ford, Dimitrios N. Karnabatidis, George K. Loudos, Handbook of Small Animal Imaging, 2018
In optical imaging, two phenomena (fluorescence and bioluminescence) are used to produce light originating from tissues, which is then monitored by a common CCD camera and recorded for processing. Typically, molecules are labeled with fluorescent moieties (i.e., cyanine-based Cy3 or Cy5 dyes), injected to the biological system, and their biodistribution is followed in vivo using 2D or 3D optical system scanners. Another method uses transfection of cells with a gene (i.e., green fluorescence protein [GFP] gene), which can be used to study cell function in vivo. Despite the clear advantages of fluorescence imaging, such as relatively easy usability, high throughput, inexpensive, and lack of ionizing radiation, its clinical translation is limited by reduced depth of penetration (in millimeters), surface reflectance, absorption (i.e., by hemoglobin), scattering, and autofluorescence. On the other hand, bioluminescence is more sensitive and is not affected by surface reflectance or scattering, although it still suffers from limited penetration depth. All of these disadvantages practically excluded optical techniques from clinical whole-body 3D imaging and limited their use to only local investigations including image-guided surgery applications or postmortem tissue analyses (Lee et al. 2012).
Introduction to optical imaging
Published in Ahmad Fadzil Mohamad Hani, Dileep Kumar, Optical Imaging for Biomedical and Clinical Applications, 2017
Dileep Kumar, Ahmad Fadzil Mohamad Hani
Fimaging and bioluminescence imaging are used to obtain whole body imaging. Fluorescence imaging is the technique in which molecules of the tissue are excited with external light source and because of the fluorescence material the molecule gets excited and releases longer wavelength light ranging in between UV to NIR range when settling down to ground state. Similarly, the bioluminescence is the natural property of certain living tissues that emit light when it meets certain substrate.
Evaluation of tissue-clearing techniques for intraorgan imaging of distribution of polymeric nanoparticles as drug carriers
Published in Drug Development and Industrial Pharmacy, 2020
Kiyomi Ishizawa, Kohei Togami, Hitoshi Tada, Sumio Chono
Drug delivery systems using nanocarriers, such as polymeric nanoparticles [1–3] and liposomes [4–6], have been developed to enhance therapeutic effects and reduce systemic side effects in the treatment of various diseases. For achieving effective drug delivery, the delivery efficiency must be evaluated through both quantitation at organ, tissue, and cellular scales and visualization at the focus sites. In this context, various imaging methods, such as positron emission tomography (PET), single-photon emission computed tomography (SPECT), X-ray computed tomography (CT), and fluorescence imaging, are used for evaluating the distribution of nanocarriers [7–10]. Although PET, SPECT, and X-ray CT enable noninvasive three-dimensional (3D) imaging due to the high tissue penetration of radiation, cellular-scale observation is difficult due to their low resolution [11]. Fluorescence imaging methods enable both macro- and micro-scale observation using fluorescence imaging instruments, including in vivo imagers and microscopes. However, since fluorescence imaging is limited by the problem of light attenuation, fluorescence imaging of intraorgans is difficult without damaging the tissue. Therefore, despite the widespread use of fluorescence imaging for observing thin tissue sections [12–14], this method is not accurate because of the possibility of the loss of distributed nanoparticles due to the damages in tissues and cells caused by slicing.
Clinical role of fluorescence imaging in colorectal surgery - an updated review
Published in Expert Review of Medical Devices, 2020
Amandeep Ghuman, Sandra Kavalukas, Stephen P. Sharp, Steven D. Wexner
The role of fluorescence imaging has been expanding. It was initially used to assess bowel perfusion to ensure well-vascularized anastomoses were created with the hypothesis this objective assessment may lead to reduction in AL. Although the results of the two RCTs are conflicting and the preliminary data from PILLAR III did not establish a clear correlation, likely due to small sample size since study was terminated early, the potential benefits may still exist. Establishing a clear role for ICG in AL reduction will require consistency in the definition of AL used in the literature, along with standardized anastomotic measurements, as more distal (lower) anastomoses are known to carry higher risk of AL than are the more proximal (higher) ones. In the current literature there does appear to be a reduction in AL with ICG for rectal cancer resections, which could be due to higher AL at baseline with these lower anastomoses. Given the multifactorial nature of risk factors for colorectal AL, larger multi-center RCTs may be required to delineate a clear role.
Nanotheranostics, a future remedy of neurological disorders
Published in Expert Opinion on Drug Delivery, 2019
Manju Sharma, Taru Dube, Sonika Chibh, Avneet Kour, Jibanananda Mishra, Jiban Jyoti Panda
In the past few years, a surge in the application of nanotheranostics as therapeutic or diagnostic/imaging entity has been witnessed in the treatment/diagnosis of various neural ailments. Major components of a nanotheranostic system include imaging/diagnostic agents and nanocarriers. Diagnostic nano-agents such as quantum dots (QDs), fluorescent dyes, iron oxides, radionuclides, heavy metals, etc., have been combined with various brain imaging techniques such as PET, MRI, X-ray CT, SPECT, etc., for the in-depth investigation of the pathology of neural diseases. However, PET and SPECT are disadvantageous over other imaging methods, as they employ radioactive probes that emit ionizing radiation, which may affect the surrounding healthy tissues. In this context, fluorescence imaging is encouraging with the benefits of being cost-effective, superior contrast/signal generation, elevated sensitivity and safety, and real-time assessment of unhealthy tissues. This tool can be strategically designed for specific markers overexpressed at the affected region and subsequent activation at the target sites. Additionally, employment of fluorescent probes in the infrared region can engender an augmented pervasion with diminished signal scattering; hence in-depth visualization of diseased tissues would be feasible.