Average fluorescence intensity is affected by distance and penetration depth with near-infrared fluorescence imaging with indocyanine green in an ex vivo model.
Adrianna K Szostek, Janet A Grimes, Mandy L Wallace
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引用次数: 0
Abstract
Objective: The objective of this study was to evaluate the effect of indocyanine green (ICG) concentration, distance, angle, and penetration depth on average fluorescence intensity (AFI) when using 2 imaging devices in a canine ex vivo model.
Methods: 3 concentrations of ICG were evaluated (0.006, 0.011, and 0.022 mg/mL) for the effect of distance, penetration depth, angle, and ambient light on AFI. Penetration depth was assessed using serially stacked 1-mm sheets of a gelatin phantom. Each set of conditions was tested using a VITOM 3D and 30° 10-mm laparoscope. Polynomial regression was used to evaluate for significance.
Results: Average fluorescence intensity increased with increasing distance for the 30° 10-mm laparoscope. The VITOM 3D displayed higher AFIs at closer and farther distances. Average fluorescence intensity decreased as penetration depth increased for both devices. Ambient light had no effect on AFI, and AFI varied by angle, but statistical analysis for these variables was limited by insufficient data points.
Conclusions: Average fluorescence intensity was affected by distance, penetration depth, and angle for each ICG concentration and imaging device. There was no apparent effect on AFI with or without ambient light.
Clinical relevance: The interest in near-infrared fluorescence with ICG is growing in veterinary medicine. Optimization of protocols using these techniques can provide veterinarians with guidelines for the implementation of near-infrared fluorescence with ICG. Further studies are needed to assess the relationship between distance, depth, angle, and ambient light with AFI in vivo.
期刊介绍:
The American Journal of Veterinary Research supports the collaborative exchange of information between researchers and clinicians by publishing novel research findings that bridge the gulf between basic research and clinical practice or that help to translate laboratory research and preclinical studies to the development of clinical trials and clinical practice. The journal welcomes submission of high-quality original studies and review articles in a wide range of scientific fields, including anatomy, anesthesiology, animal welfare, behavior, epidemiology, genetics, heredity, infectious disease, molecular biology, oncology, pharmacology, pathogenic mechanisms, physiology, surgery, theriogenology, toxicology, and vaccinology. Species of interest include production animals, companion animals, equids, exotic animals, birds, reptiles, and wild and marine animals. Reports of laboratory animal studies and studies involving the use of animals as experimental models of human diseases are considered only when the study results are of demonstrable benefit to the species used in the research or to another species of veterinary interest. Other fields of interest or animals species are not necessarily excluded from consideration, but such reports must focus on novel research findings. Submitted papers must make an original and substantial contribution to the veterinary medicine knowledge base; preliminary studies are not appropriate.