Multi-modality measurement and comprehensive analysis of hepatocellular carcinoma using synchrotron-based microscopy and spectroscopy

The visualization and data mining of tumor multidimensional information may play a major role in the analysis of the growth,metastasis,and microenvironmental changes of tumors while challenging traditional imaging and data processing techniques.In this study,a general trans-scale and multi-modality measurement method was developed for the quantitative diagnosis of hepatocellular carcinoma(HCC)using a combination of propagation-based phase-contrast computed tomography(PPCT),scanning transmission soft X-ray microscopy(STXM),and Fourier transform infrared micro-spectroscopy(FTIR).Our experimental results reveal the trans-scale micro-morpho-logical HCC pathology and facilitate quantitative data analysis and comprehensive assessment.These results include some visualization features of PPCT-based tissue microenvironments,STXM-based cellular fine structures,and FTIR-based bio-macromolecular spectral characteris-tics during HCC tumor differentiation and proliferation.The proposed method provides multidimensional feature data support for constructing a high-accuracy machine learning algorithm based on a gray-level histogram,gray-gradient co-occurrence matrix,gray-level co-occurrence matrix,and back-propagation neural network model.Multi-dimensional information analysis and diagnosis revealed the morphological pathways of HCC pathological evolution and we explored the relationships between HCC-related feature changes in inflammatory microenviron-ments,cellular metabolism,and the stretching vibration peaks of biomolecules of lipids,proteins,and nucleic acids.Therefore,the proposed methodology has strong potential for the visualization of complex tumors and assessing the risks of tumor differentiation and metastasis.

基于机器学习方法的肝癌X射线相衬CT图像分类研究

肝癌是我国恶性肿瘤发病率和死亡率较高的癌症之一,传统医学影像设备因成像机制导致成像分辨率不足,对肝癌的检查和诊断具有较大的影响。基于同步辐射的X射线相衬显微CT成像具有极高的灵敏度和分辨率,结合机器学习方法建立肝癌分类模型,为肝癌辅助诊断提供参考。收集弥漫型和溃疡型肝肿瘤X射线相衬图像各500幅,归一化和中值滤波后提取灰度直方图、灰度共生矩阵、灰度-梯度共生矩阵和灰度差分统计等灰度及纹理特征,并组合成融合特征,采用十折交叉验证法进行机器学习方法的训练和分类。使用支持向量机、随机森林和神经网络等3种分类算法对肝癌图像进行分类,灰度共生矩阵特征和神经网络分类算法下分类准确率最高,达到99.5%,取得较好的分类效果,有望帮助医生准确完成肝肿瘤类型的鉴别。

Performance analysis of quantitative phase retrieval method in Zernike phase contrast X-ray microscopy

Since the invention of Zernike phase contrast method in 1930,it has been widely used in optical microscopy and more recently in X-ray microscopy.Considering the image contrast is a mixture of absorption and phase information,we recently have proposed and demonstrated a method for quantitative phase retrieval in Zernike phase contrast X-ray microscopy.In this contribution,we analyze the performance of this method at different photon energies.Intensity images of PMMA samples are simulated at 2.5 keV and 6.2 keV,respectively,and phase retrieval is performed using the proposed method.The results demonstrate that the proposed phase retrieval method is applicable over a wide energy range.For weakly absorbing features,the optimal photon energy is 2.5 keV,from the point of view of image contrast and accuracy of phase retrieval.On the other hand,in the case of strong absorption objects,a higher photon energy is preferred to reduce the error of phase retrieval.These results can be used as guidelines to perform quantitative phase retrieval in Zernike phase contrast X-ray microscopy with the proposed method.

Explosion Event of Cavitation in Intact Xylem Conduit

Cavitation in plant conduits only involves two processes of air bubbles: the gradual expansion and elongation, and the explosion event. An explosion event of cavitation, which can only occur in intact conduit at water tension, trigs acoustic (or ultrasound) emission and induces air to diffuse with high speed, simultaneously. Synchrotron X-ray phase contrast microscopy (XPCM) was used to capture cavitation event in intact conduits of leaves of corn and rice. Cavitation events occur in certain areas of leaves and have a certain time frame. Before XPCM experiment, several preliminary experiments were done as follows: 1) Paraffin sections of leaves of different species were observed to select samples and to determine the occurrence area of cavitation event of leaves. 2) The time frame of cavitation occurrence was determined by ultrasonic emission. 3) The water potentials of leaves were determined, to know the water state of the leaves during cavitation. Locked the area and time frame of cavitation event in the leaves, consecutive XPCM images of cavitation process were more easily acquired. The images show that the phenomenon of gas bubble fully filling conduits for an instant took place in intact conduits of detached leaves of corn and rice more easily. It is that the gas diffusing in a moment was caused by the explosion of the air seeds which had entered in the intact conduits of the leaves. For living plants, it is suggested that the explosion event of cavitation is the most important for embolism formation.

基于同步辐射X射线相衬显微CT技术的煤孔隙结构表征

以上海同步辐射装置产生的同步X射线束为光源,对3种不同变质程度煤样的相位衬度CT成像和重构二维横截面投影,得到煤样和煤中矿物质的三维立体图像,经定量分析可知煤样的总孔隙体积、单个矿物质最大体积、矿物质总数以及矿物质平均体积等参数。结果表明:随着变质程度的加深,煤中总孔隙体积和矿物质平均体积均呈逐渐减少趋势,煤中孔隙从大孔逐渐过渡到大中孔和微孔,呈逐渐紧密化的物理结构特征。

X-ray computed tomography of adhesive wicking into carbon foam

Laser target components consist of multicomponent porous and nonporous materials that are adhesively bonded together.In order to assess the extent and quantity of adhesive wicking into porous foam, micro X-ray computed tomography(CT)and image processing software have been utilized. Two different laser target configurations have been assessed in situ and volume rendered images of the distribution and quantities of adhesive have been determined for each.