■在背侧皮褶窗室(DSWC)中生长的鼠肿瘤模型的高光谱成像(HSI)提供了对肿瘤微环境的宝贵见解。然而,玻璃盖玻片中的光损失经常被忽视,并且特定的组织特征被不正确地建模,导致从高光谱图像中提取的组织特性误差。
■我们强调了DSWC模型的HSI中光谱重新归一化的重要性,并证明了在皮肤组织模型中掺入增强的绿色荧光蛋白(EGFP)激发和发射对于表达基因的肿瘤产生EGFP的益处。
■我们使用HSI系统在DSWC中对患有4T1乳腺癌的小鼠进行了14天的活体成像。我们根据测得的玻璃盖玻片的反射光谱对高光谱图像进行了光谱归一化处理,并利用了双层鼠类皮肤模型的反向倍加(IAD)算法,提取组织参数,如总血红蛋白浓度和组织氧合(StO2)。升级模型以考虑EGFP荧光激发和发射。此外,我们进行了其他涉及组织体模的实验,人类前臂皮肤成像,和数值模拟。
■高光谱图像归一化和在小鼠皮肤模型中添加EGFP荧光可将拟合和测量光谱的平均绝对百分比误差(MAPE)在组织体模中降低多达10%,在人体前臂实验和数值模拟中,0.55%至1.5%,在4T1肿瘤中高达0.7%。同样,在人类前臂和数值模拟中,通过IAD提取的组织参数的MAPE降低了3%.对于某些参数,在4T1肿瘤中观察到统计学显著差异(p<0.05)。最终,我们已经表明,荧光发射可能有助于4T1肿瘤分割。
■结果有助于改善使用HSI对DWSC模型的活体监测,并为更准确和精确的定量成像铺平道路。
UNASSIGNED: Hyperspectral imaging (HSI) of murine tumor models grown in dorsal skinfold window chambers (DSWCs) offers invaluable insight into the tumor microenvironment. However, light loss in a glass coverslip is often overlooked, and particular tissue characteristics are improperly modeled, leading to errors in tissue properties extracted from hyperspectral images.
UNASSIGNED: We highlight the significance of spectral renormalization in HSI of DSWC models and demonstrate the benefit of incorporating enhanced green fluorescent protein (EGFP) excitation and emission in the skin tissue model for tumors expressing genes to produce EGFP.
UNASSIGNED: We employed an HSI system for intravital imaging of mice with 4T1 mammary carcinoma in a DSWC over 14 days. We performed spectral renormalization of hyperspectral images based on the measured reflectance spectra of glass coverslips and utilized an inverse adding-doubling (IAD) algorithm with a two-layer murine skin model, to extract tissue parameters, such as total hemoglobin concentration and tissue oxygenation ( StO 2 ). The model was upgraded to consider EGFP fluorescence excitation and emission. Moreover, we conducted additional experiments involving tissue phantoms, human forearm skin imaging, and numerical simulations.
UNASSIGNED: Hyperspectral image renormalization and the addition of EGFP fluorescence in the murine skin model reduced the mean absolute percentage errors (MAPEs) of fitted and measured spectra by up to 10% in tissue phantoms, 0.55% to 1.5% in the human forearm experiment and numerical simulations, and up to 0.7% in 4T1 tumors. Similarly, the MAPEs for tissue parameters extracted by IAD were reduced by up to 3% in human forearms and numerical simulations. For some parameters, statistically significant differences ( p < 0.05 ) were observed in 4T1 tumors. Ultimately, we have shown that fluorescence emission could be helpful for 4T1 tumor segmentation.
UNASSIGNED: The results contribute to improving intravital monitoring of DWSC models using HSI and pave the way for more accurate and precise quantitative imaging.