Fluorescence spectroscopy is widely used for biomedical optical diagnosis and surgical resection of tumours. This work investigates laser-induced fluorescence spectroscopy of fluorescence inclusions that are embedded in turbid media. 405 nm laser diode is used for exciting buried protoporphyrin- (PpIX) based inclusions in brain-like optical phantoms. Effects of scattering and absorption of the turbid medium on the recorded fluorescence signal and depth-resolved fluorescence were studied. Results show that optical properties of the surrounding turbid medium influence the intensity of the fluorescence signal. Absorption coefficient of the surrounding medium is the major contributor to the fluorescent signal. Analysis of the recorded fluorescence spectra shows that the effect of absorption coefficient is larger than the effect of scattering coefficient on the fluorescence intensity by nearly fivefold. The findings indicate that the fluorescence signal could be used as a biomarker of optical property variations through different stages of malignancy. This can enhance the detectability of malignant tissue for diagnostic and surgical purposes as well.

中文翻译：

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吸收和散射对埋藏肿瘤荧光的影响

荧光光谱法广泛用于生物医学光学诊断和肿瘤手术切除。这项工作研究了嵌入浑浊介质中的荧光夹杂物的激光诱导荧光光谱。405 nm激光二极管用于激发类似大脑的幻影中的隐埋原卟啉（PpIX）。研究了混浊介质的散射和吸收对记录的荧光信号和深度分辨荧光的影响。结果表明，周围混浊介质的光学性质会影响荧光信号的强度。周围介质的吸收系数是荧光信号的主要贡献者。对记录的荧光光谱的分析表明，吸收系数的影响比散射系数对荧光强度的影响大近五倍。这些发现表明，荧光信号可以用作通过恶性肿瘤的不同阶段的光学特性变化的生物标记。这也可以增强用于诊断和手术目的的恶性组织的可检测性。