Duan Jinghao, Hu Chunhong, Qiu Qingtao, Zhang Jing, Meng Huipeng, Wang Keqiang, Dong Huajiang, Wei Hong, Yin Yong
School of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin 300072, China.
Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Ji'nan 250117, China.
Quant Imaging Med Surg. 2019 Jun;9(6):1037-1046. doi: 10.21037/qims.2019.06.12.
Hepatocellular carcinoma (HCC) is a cancer with a poor prognosis, and approximately 80% of HCC cases develop from cirrhosis. Imaging techniques in the clinic seem to be insufficient for revealing the microstructures of liver disease. In recent years, phase contrast imaging CT (PCI-CT) has opened new avenues for biomedical applications owing to its unprecedented spatial and contrast resolution. The aim of this study was to present three-dimensional (3D) visualization of human healthy liver, cirrhosis and HCC using a PCI-CT technique called in-line phase contrast imaging CT (ILPCI-CT) and to quantitatively evaluate the variations of these tissues, focusing on the liver parenchyma and microvasculature.
Tissue samples from 9 surgical specimens of normal liver (n=3), cirrhotic liver (n=2), and HCC (n=4) were imaged using ILPCI-CT at the Shanghai Synchrotron Radiation Facility (SSRF) without contrast agents. 3D visualization of all liver samples are presented. To quantitatively evaluate the vessel features, the vessel branch angles of each sample were clearly depicted. Additionally, radiomic features of the liver parenchyma extracted from the 3D images were measured. To evaluate the stability of the features, the percent coefficient of variation (%COV) was calculated for each radiomic feature. A %COV <30 was considered to be low variation. Finally, one-way ANOVA, followed by Tukey's test, was used to determine significant changes among the different liver specimens.
ILPCI-CT allows for a clearer view of the architecture of the vessels and reveals more structural details than does conventional radiography. Combined with the 3D visualization technique, ILPCI-CT enables the acquisition of an accurate description of the 3D vessel morphology in liver samples. Qualitative descriptions and quantitative assessment of microvessels demonstrated clear differences among human healthy liver, cirrhotic liver and HCC. In total, 38 (approximately 51%) radiomic features had low variation, including 11 first-order features, 16 GLCM features, 6 GLRLM features and 5 GLSZM features. The differences in the mean vessel branch angles and 3 radiomic features (first-order entropy, GLCM-inverse variance and GLCM-sum entropy) were statistically significant among the three groups of samples.
ILPCI-CT may allow for morphologic descriptions and quantitative evaluation of vessel microstructures and parenchyma in human healthy liver, cirrhotic liver and HCC. Vessel branch angles and radiomic features extracted from liver parenchyma images can be used to distinguish the three kinds of liver tissues.
肝细胞癌（HCC）预后较差，约80%的HCC病例由肝硬化发展而来。临床中的成像技术在揭示肝脏疾病微观结构方面似乎存在不足。近年来，相衬成像CT（PCI-CT）凭借其前所未有的空间和对比度分辨率，为生物医学应用开辟了新途径。本研究的目的是使用一种名为在线相衬成像CT（ILPCI-CT）的PCI-CT技术对人类健康肝脏、肝硬化和HCC进行三维（3D）可视化，并定量评估这些组织的变化，重点关注肝实质和微血管系统。
在上海同步辐射装置（SSRF）使用ILPCI-CT对9个手术标本（正常肝脏n=3、肝硬化肝脏n=2、HCC n=4）的组织样本进行成像，无需使用造影剂。展示了所有肝脏样本的3D可视化。为了定量评估血管特征，清晰描绘了每个样本的血管分支角度。此外，测量了从3D图像中提取的肝实质的放射组学特征。为了评估特征的稳定性，计算了每个放射组学特征的变异系数百分比（%COV）。%COV<30被认为变异低。最后，使用单因素方差分析，随后进行Tukey检验，以确定不同肝脏标本之间的显著变化。
与传统放射成像相比，ILPCI-CT能更清晰地显示血管结构并揭示更多结构细节。结合3D可视化技术，ILPCI-CT能够准确描述肝脏样本中3D血管形态。对微血管的定性描述和定量评估表明，人类健康肝脏、肝硬化肝脏和HCC之间存在明显差异。总共有38个（约51%）放射组学特征变异低，包括11个一阶特征、16个灰度共生矩阵（GLCM）特征、6个灰度游程长度矩阵（GLRLM）特征和5个灰度大小区域矩阵（GLSZM）特征。三组样本之间平均血管分支角度和3个放射组学特征（一阶熵、GLCM-逆方差和GLCM-和熵）的差异具有统计学意义。
ILPCI-CT可能允许对人类健康肝脏、肝硬化肝脏和HCC中的血管微观结构和实质进行形态学描述和定量评估。从肝实质图像中提取的血管分支角度和放射组学特征可用于区分这三种肝脏组织。
