Label-Free Assessment of Premalignant Gastric Lesions Using Multimodal Nonlinear Optical Microscopy

In this paper, a nonlinear optical microscopy employing two-photon excited fluorescence and second-harmonic generation was used for the detection of premalignant gastric lesions. It was found that gland morphology and collagen structure in mucosa will change with the progression of gastric diseases from normal to intestinal metaplasia, to low-grade intraepithelial neoplasia, and to high-grade intraepithelial neoplasia, and this microscopy was able to directly distinguish these warning symptoms. Furthermore, two features were quantified from nonlinear optical images to demonstrate the changes of gland size and collagen content during the development process of preneoplastic lesions. These results clearly show that nonlinear optical microscopy can effectively differentiate normal and precancerous gastric tissues without contrast agents, which would be helpful for early diagnosis and treatment of gastric diseases. This study may provide the groundwork for further application of nonlinear optical microscopy in clinical practice.