Homogenized tissue phantoms for quantitative evaluation of subsurface fluorescence contrast

Roy, Mathieu; Kim, Anthony; Dadani, Farhan N.; Wilson, Brian C.

doi:10.1117/1.3528646

Cited by 17 publications

(27 citation statements)

References 28 publications

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“…2.2 and 4.2, subsurface imaging was performed for all tissue samples, but, for the sake of brevity, the results are not reported above, since this was examined in detail in phantoms and homogenized tissues previously 10 and, as noted, most subsurface measurements suffered from lack of QD signal due to strong tissue attenuation, as considered elsewhere. 23 Despite this suboptimal data quality, it was still possible to identify and confirm general trends on the effect of depth on wavelength optimization.…”

Section: Impact Of Target Depthmentioning

confidence: 99%

“…Images were corrected for the camera noise, excitation lamp spectrum, exposure time and spatial illumination profile, and analysed as previously described. 10 The measured image contrast, or target-to-background ratio (TBR), is defined as the ratio of fluorescence signals emitted by the target (in this case the QD-filled capillary) and background regions of interest:…”

Section: Fluorescence Imaging and Image Analysismentioning

confidence: 99%

“…10 All measurements were done under high signal-to-noise conditions, using 12 excitation filters ranging from 385 to 620 nm (average bandwidth 20 nm) and five emission filters corresponding to the QD emission peaks at 500, 550, 600, 650, and 700 nm (bandwidth 50 nm). Images were corrected for the camera noise, excitation lamp spectrum, exposure time and spatial illumination profile, and analysed as previously described.…”

Section: Fluorescence Imaging and Image Analysismentioning

confidence: 99%

“…10 Here, in order to validate the method further using tissues with a range of optical properties, fresh (not previously frozen) porcine kidney and liver, and bovine brain and lung were used. Each tissue was homogenized and diluted following the previous protocol.…”

Section: Tissue Preparationmentioning

confidence: 99%

“…10 In a previous study, we demonstrated the validity of this approach using artificial liquid phantoms of known optical properties and homogenized liver as a proof-of-principle model tissue. This led to the following provisional conclusions regarding contrast optimization: 1. it is advantageous for surface imaging to use an excitation wavelength corresponding to a tissue absorption peak, since this reduces the tissue autofluorescence background and 2. the contrast falls rapidly with depth of the QDs, at a rate that increases predominantly with tissue absorption, leading to spectral shifts and overall flattening of the spectral contrast.…”

Section: Introductionmentioning

confidence: 99%

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Effect of tissue optics on wavelength optimization for quantum dot-based surface and subsurface fluorescence imaging

et al. 2012

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Abstract. Optimization is an important but relatively unexplored aspect of contrast-enhanced fluorescence imaging, since minimizing contrast agent usage reduces the associated cost and potential toxicity. In a previous study, the authors developed a quantitative experimental approach to optimize quantum dot (QD)-based imaging using homogenized liver as a model tissue. In this follow-up study, the authors further extend and validate the approach using eight different tissues and five QDs emission wavelengths, and introduce quantitative imaging performance metrics, namely the threshold QD concentration and wavelength optimization gain. These metrics allow quantification of the improvements through spectral optimization in terms of reduced QD dose and identify the conditions that make the optimization process worthwhile. The authors show that, for most tissues, the most important parameter to optimize is the emission wavelength, yielding improvements of up to four orders of magnitude, followed by the excitation wavelength (up to 20-fold improvement) and the excitation filter bandwidth (up to 50% improvement). The authors also observe, by means of the optimization gain metric, that tissues exhibiting both high autofluorescence and strong pigmentation are generally better candidates for excitation wavelength optimization. This work contributes to the development of robust and quantitative dosimetry for QD-based fluorescence imaging near to the tissue surface.

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Section: Impact Of Target Depthmentioning

confidence: 99%

Section: Fluorescence Imaging and Image Analysismentioning

confidence: 99%

Section: Fluorescence Imaging and Image Analysismentioning

confidence: 99%

Section: Tissue Preparationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Effect of tissue optics on wavelength optimization for quantum dot-based surface and subsurface fluorescence imaging

et al. 2012

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A Novel Solid Lipid Nanoparticle Formulation for Active Targeting to Tumor α_vβ₃ Integrin Receptors Reveals Cyclic RGD as A Double‐Edged Sword

Shuhendler

Prasad

Leung

et al. 2012

Adv Healthcare Materials

102

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The overexpression of α(v) β(3) integrin receptors on tumor cells and tumor vascular endothelium makes it a useful target for imaging, chemotherapy and anti-angiogenic therapy. However integrin-targeted delivery of therapeutics by nanoparticles have provided only marginal, if any, enhancement of therapeutic effect. This work was thus focused on the development of novel α(v) β(3) -targeted near infrared light-emitting solid lipid nanoparticles (SLN) through conjugation to the α(v) β(3) integrin-specific ligand cyclic Arg-Gly-Asp (cRGD), and the assessment of the effects of α(v) β(3) targeting on nanoparticle biodistribution. Since our previously developed non-targeted "stealth" SLN showed little hepatic accumulation, unlike most reported liposomes and micelles, they served as a reference for quantifying the effects of cRGD-conjugation on tumor uptake and whole animal biodistribution of SLN. Non-targeted SLN, actively targeted (RGD-SLN) and blocked RGD-SLN were prepared to contain near infrared quantum dots for live animal imaging. They were injected intravenously to nude mice bearing xenograft orthotopic human breast tumors or dorsal window chamber breast tumors. Tumor micropharmacokinetics of various SLN formulations were determined using intravital microscopy, and whole animal biodistribution was followed over time by optical imaging. The active tumor targeting with cRGD was found to be a "double-edged sword": while the specificity of RGD-SLN accumulation in tumor blood vessels and their tumor residence time increased, their distribution in the liver, spleen, and kidneys was significantly greater than the non-targeted SLN, leaving a smaller amount of nanoparticles in the tumor tissue. Nevertheless the enhanced specificity and retention of RGD-SLN in tumor neovasculature could make this novel formulation useful for tumor neovascular-specific therapies and imaging applications.

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AAPM Task Group Report 311: Guidance for performance evaluation of fluorescence‐guided surgery systems

Pogue,

Zhu,

Ntziachristos

et al. 2023

Medical Physics

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The last decade has seen a large growth in fluorescence‐guided surgery (FGS) imaging and interventions. With the increasing number of clinical specialties implementing FGS, the range of systems with radically different physical designs, image processing approaches, and performance requirements is expanding. This variety of systems makes it nearly impossible to specify uniform performance goals, yet at the same time, utilization of different devices in new clinical procedures and trials indicates some need for common knowledge bases and a quality assessment paradigm to ensure that effective translation and use occurs. It is feasible to identify key fundamental image quality characteristics and corresponding objective test methods that should be determined such that there are consistent conventions across a variety of FGS devices. This report outlines test methods, tissue simulating phantoms and suggested guidelines, as well as personnel needs and professional knowledge bases that can be established. This report frames the issues with guidance and feedback from related societies and agencies having vested interest in the outcome, coming from an independent scientific group formed from academics and international federal agencies for the establishment of these professional guidelines.

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Homogenized tissue phantoms for quantitative evaluation of subsurface fluorescence contrast

Cited by 17 publications

References 28 publications

Effect of tissue optics on wavelength optimization for quantum dot-based surface and subsurface fluorescence imaging

Effect of tissue optics on wavelength optimization for quantum dot-based surface and subsurface fluorescence imaging

A Novel Solid Lipid Nanoparticle Formulation for Active Targeting to Tumor α_vβ₃ Integrin Receptors Reveals Cyclic RGD as A Double‐Edged Sword

AAPM Task Group Report 311: Guidance for performance evaluation of fluorescence‐guided surgery systems

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Homogenized tissue phantoms for quantitative evaluation of subsurface fluorescence contrast

Cited by 17 publications

References 28 publications

Effect of tissue optics on wavelength optimization for quantum dot-based surface and subsurface fluorescence imaging

Effect of tissue optics on wavelength optimization for quantum dot-based surface and subsurface fluorescence imaging

A Novel Solid Lipid Nanoparticle Formulation for Active Targeting to Tumor αvβ3 Integrin Receptors Reveals Cyclic RGD as A Double‐Edged Sword

AAPM Task Group Report 311: Guidance for performance evaluation of fluorescence‐guided surgery systems

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A Novel Solid Lipid Nanoparticle Formulation for Active Targeting to Tumor α_vβ₃ Integrin Receptors Reveals Cyclic RGD as A Double‐Edged Sword