Grating-based phase-contrast imaging of tumor angiogenesis in lung metastases.

Huimin Lin,Bei Ding,Yujie Wang,Rongbiao Tang,Fuhua Yan,Binquan Kou,Huanhuan Liu,Xiangting Li,Huan Zhang,Jianqi Sun,Chen Shi

doi:10.1371/journal.pone.0121438

Abstract

PurposeTo assess the feasibility of the grating-based phase-contrast imaging (GPI) technique for studying tumor angiogenesis in nude BALB/c mice, without contrast agents.MethodsWe established lung metastatic models of human gastric cancer by injecting the moderately differentiated SGC-7901 gastric cancer cell line into the tail vein of nude mice. Samples were embedded in a 10% formalin suspension and dried before imaging. Grating-based X-ray phase-contrast images were obtained at the BL13W beamline of the Shanghai Synchrotron Radiation Facility (SSRF) and compared with histological sections.ResultsWithout contrast agents, grating-based X-ray phase-contrast imaging still differentiated angiogenesis within metastatic tumors with high spatial resolution. Vessels, down to tens of microns, showed gray values that were distinctive from those of the surrounding tumors, which made them easily identifiable. The vessels depicted in the imaging study were similar to those identified on histopathology, both in size and shape.ConclusionsOur preliminary study demonstrates that grating-based X-ray phase-contrast imaging has the potential to depict angiogenesis in lung metastases.

Highlights

Angiogenesis is traditionally known as the growth of new capillary blood vessels from preexisting ones
Our preliminary study demonstrates that grating-based X-ray phase-contrast imaging has the potential to depict angiogenesis in lung metastases
There was a significant difference in the gray values between the blood vessels and the surrounding tumor tissue [Fig. 2E]

Summary

Introduction

Angiogenesis is traditionally known as the growth of new capillary blood vessels from preexisting ones. Because new blood vessels carry nutrients and oxygen into tumors and transport catabolites and carbon dioxide away from them, angiogenesis plays a critical role in the growth of cancer [2,3], from the initial growth to a clinical detectable size, to the development of a metastatic or lethal phenotype, until eventually killing its host [4,5,6,7,8]. Treatment efforts have been made to disturb this process [9,10]. These therapies have inspired many research activities in the assessment of tumor vascularity to monitor therapeutic effects, e.g., histological assessment of microvessel density (MVD) and angiogenesis imaging

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Results

Conclusion