What is the optimal way to manage this CT finding? Should we adopt surgical removal or just observation? An optimal solution is to determine a clearly defined standard of care that is easy to learn. We propose a method called "three plus two". The 'Three' is a three-step testing method, and the 'Two' means two alternative solutions. Three-step testing method includes collecting medical history, non-invasive examination, and invasive examination. The two alternative solutions are surgical removal and follow-up observation. We have independently developed an application based on a smartphone platform. This platform will provide a novel evidence-based research method for observing the dynamic evolution of the lung nodules in patients. There have been no prior studies about managing this CT scan finding, either in China or internationally.