共查询到18条相似文献,搜索用时 140 毫秒
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采用Er:YAG激光(波长为2 940 nm,能量密度为:2.5 J/cm2单光斑,扫描次数为4)照射活体小白鼠皮肤,利用光学相干层析成像(optical coherence tomography,OCT)技术在活体小鼠上观察其皮肤组织在激光作用之前及作用之后光热损伤修复的整个过程,得到了激光光热作用下引起损伤的皮肤组织在此过程中皮肤光学特性参数的变化情况,发现皮肤修复过程中光学参数有显著差异,并分析了这些差异引起的原因,以揭示激光美容中并发症主要因素。 相似文献
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皮肤光老化是一个极其复杂的渐进过程,不仅有临床及组织学方面变化,还有生物化学方面变化。无损、非侵入式的皮肤光老化评价技术和组织热损伤定量技术促进了光学治疗技术的发展,有助于优化选择非消融性光治疗参数。评述了基于光学方法的皮肤光老化评价和治疗技术研究进展。 相似文献
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建立小鼠皮肤的Ⅱ度烫伤的模型,分别于烫伤前、烫伤后1 min、8 h、1 d、3 d、5 d、7 d、9 d、11 d、13 d、15 d、17 d,用光学相干层析成像技术(OCT)对烫伤的创面进行动态的监测,同时对创面进行组织病理学的检测,对结果进行分析。利用OCT单次散射模型获得皮肤在烫伤前后光衰减系数的变化情况,结果显示光衰减系数的值在烫伤后是呈先减小后增大的趋势,待修复完全后又恢复到烫伤前相近的值。该结果与组织病理学的结果相吻合,这表明OCT技术可以用于实时诊断烫伤的皮肤。 相似文献
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应用光学相干层析成像技术对大鼠乙酸胃溃疡模型的愈合过程进行初步检测,探讨光学层析成像技术在消化性溃疡疾病中的诊断价值及其意义.实验中应用乙酸局部刺激法建立大鼠胃溃疡模型,应用光学相干层析成像系统于模型复制后不同时期进行扫描,观察在其自然愈合过程中溃疡组织的变化情况,并且对其图像进行比较分析.结果显示:利用光学相干层析成像技术能够很准确的区别正常和非正常的胃组织,并且能够区分不同的愈合时期胃溃疡组织的图像,以及对病变组织进行一定深度的扫描.研究表明:光学相干层析成像系统对乙酸胃溃疡的愈合和复发情况的观察是一种很有发展潜力的检测手段,对其愈合质量判定亦具有一定的价值. 相似文献
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用蒙特卡罗方法模拟光在多层组织中的吸收特性 总被引:2,自引:0,他引:2
在讨论目前新颖的组织功能成像打骂能性(例如光声成像)时,光子在组织中的吸收和散射特性是一个很重要的问题,鉴于这一点,本文利用一个多层模型研究了光子在皮肤,脂肪和肌肉组织中的吸收和散射特性,得到了在组织中某一深度处光子在一个平面上的吸收分布,以及在不同吸收系数和散射系数的情况下,光子的反射,吸收和透射几率,结果表明在经过多次散射后,大部分的光子被吸收,在本文的模型中只有7.3%的光子从表面反射(包括镜面反射和漫反射),还讨论了不同光学参灵敏对参流分布的影响。 相似文献
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建立了描述温控加热方式下激光诱导肿瘤间质热疗过程中动态光热作用的二维圆柱坐标下的数学模型,采用基于网格的蒙特卡罗方法数值模拟热疗过程中激光能量在非均质生物组织内的传输过程,基于Pennes生物传热方程和Arrhen ius方程数值求解组织内的温度场和热损伤体积的变化。通过数值模拟的方法分析了激光波长、激光功率、温控范围等因素对激光诱导肿瘤间质热疗中热损伤体积的影响。数值模拟的结果表明,通过选择合适的治疗参数,可以得到各种不同大小的热疗区域。本文的结果和结论对于临床治疗方案的制定具有一定的理论指导意义。 相似文献
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Marcello M. Amaral Denise M. Zezell Adamo F. G. Monte Ana C. B. de Cara Jeann C. R. Araújo Andrea Antunes Anderson Z. Freitas 《Journal of biophotonics》2019,12(10)
We present the proof of concept of a general model that uses the tissue sample transmittance as input to estimate the depth‐resolved attenuation coefficient of tissue samples using optical coherence tomography (OCT). This method allows us to obtain an image of tissue optical properties instead of intensity contrast, guiding diagnosis and tissues differentiation, extending its application from thick to thin samples. The performance of our method was simulated and tested with the assistance of a home built single‐layered and multilayered phantoms (~100 μm each layer) with known attenuation coefficient on the range of 0.9 to 2.32 mm?1. It is shown that the estimated depth‐resolved attenuation coefficient recovers the reference values, measured by using an integrating sphere followed by the inverse adding doubling processing technique. That was corroborated for all situations when the correct transmittance value is used with an average difference of 7%. Finally, we applied the proposed method to estimate the depth‐resolved attenuation coefficient for a thin biological sample, demonstrating the ability of our method on real OCT images. 相似文献
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Ranit Shacham Idan Steinberg Amir H. Gandjbakhche Israel Gannot 《Journal of biophotonics》2014,7(6):381-391
Real‐time monitoring of the thermal penetration depth (TPD) is essential in various clinical procedures, such as Laser Interstitial Thermal Therapy (LITT). MRI is commonly used to this end, though bulky and expensive. In this paper, we present an alternative novel method for an optical feedback system based on changes in the diffused reflection from the tissue during treatment. Monte‐Carlo simulation was used to deduce the relations between the backscattered pattern and the TPD. Several methods of image analysis are developed for TPD estimation. Each yields a set of parameters which are linearly dependent on the TPD. In order to test these experimentally, tissue samples were monitored in‐vitro during treatment at multiple wavelengths. The SNR and coefficient of determination were used to compare the various methods and wavelengths and to determine the preferred method. Such system and algorithms may be used for real‐time in‐vivo control during laser thermotherapy and other clinical procedures. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Various tissue optical clearing techniques have sprung up for large volume imaging. However, there are few methods showed clearing and imaging data on different organs while most of them were focused on mouse brain, and as a result, it is difficult to select the suitable method for organs in practical applications due to lack of quantitative evaluation and comprehensive comparison. Therefore, it is necessary to evaluate and compare the performances of clearing methods for different organs. In this paper, several typical optical clearing methods were applied, including 3DISCO, uDISCO, SeeDB, FRUIT, CUBIC, ScaleS and PACT to clear intact brain, heart, kidney, liver, spleen, stomach, lung, small intestine, skin and muscle. The clearing efficiency, sample deformation, fluorescence preservation and imaging depth of these methods were quantitatively evaluated. Finally, based on the systemic evaluation of various parameters described above, the appropriate clearing method for specific organ including kidney or intestine was screened out. This paper will provide important references for selection of appropriate clearing methods in related researches. 相似文献
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Pixel classification method in optical coherence tomography for tumor segmentation and its complementary usage with OCT microangiography
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Alexander Moiseev Ludmila Snopova Sergey Kuznetsov Natalia Buyanova Vadim Elagin Marina Sirotkina Elena Kiseleva Lev Matveev Vladimir Zaitsev Felix Feldchtein Elena Zagaynova Valentin Gelikonov Natalia Gladkova Alex Vitkin Grigory Gelikonov 《Journal of biophotonics》2018,11(4)
A novel machine‐learning method to distinguish between tumor and normal tissue in optical coherence tomography (OCT) has been developed. Pre‐clinical murine ear model implanted with mouse colon carcinoma CT‐26 was used. Structural‐image‐based feature sets were defined for each pixel and machine learning classifiers were trained using “ground truth” OCT images manually segmented by comparison with histology. The accuracy of the OCT tumor segmentation method was then quantified by comparing with fluorescence imaging of tumors expressing genetically encoded fluorescent protein KillerRed that clearly delineates tumor borders. Because the resultant 3D tumor/normal structural maps are inherently co‐registered with OCT derived maps of tissue microvasculature, the latter can be color coded as belonging to either tumor or normal tissue. Applications to radiomics‐based multimodal OCT analysis are envisioned. 相似文献
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Sergey M. Zaytsev Yulia I. Svenskaya Ekaterina V. Lengert Georgy S. Terentyuk Alexey N. Bashkatov Valery V. Tuchin Elina A. Genina 《Journal of biophotonics》2020,13(4)
Hair follicles (HF) represent a drug delivery reservoir for improved treatment of skin disorders. Although various particulate systems play an important role in HF‐targeting, their optical monitoring in skin is challenging due to strong light scattering. Optical clearing is an effective approach allowing the increasing of particle detection depth in skin. The enhancement of optical probing depth (OPD) and optical detection depth (ODD) of particle localization using optical coherence tomography (OCT) was evaluated under application of various optical clearing agents (OCAs) together with skin permeability enhancers ex vivo in rats. Efficient OPD increasing was demonstrated for all investigated OCAs. However, skin dehydration under action of hyperosmotic agents led to the worsening of OCT‐contrast in dermis decreasing the ODD. Lipophilic agents provided optical clearing of epidermis without its dehydration. The highest ODD was obtained at application of a PEG‐400/oleic acid mixture. This OCA was tested in vivo showing beneficial ODD and OPD enhancement. 相似文献
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目的:探讨活体组织液体含量的改变对OCT成像的影响,以期提高OCT在诊断组织病理性质方面的能力。方法:实验中复制脱水大鼠病理模型,应用光学相干层析成像设备,进行大鼠舌浅表组织在体显微成像检测,并对图像中组织的信号衰减特性进行量化分析。结果:正常对照组大鼠体重明显增加,病理模型组显著下降,病理模型组于脱水3天和5天后组织的平均OCT信号衰减系数明显高于正常对照组(P<0.01),且5天较3天的病理模型组组织的信号衰减系数变化尤其显著(P<0.01)。结论:改变组织含液量,可显著改变OCT成像效果,且通过对OCT图像中信号的衰减系数分析,可获得组织细微的散射变化,从而有望提高OCT技术在组织性质方面的诊断能力。 相似文献