Fig. 4From: The correlation between tumor radiological features and spread through air spaces in peripheral stage IA lung adenocarcinoma: a propensity score-matched analysisThe smooth fitting curve between the CTR of the primary tumor and STAS. The smooth fitting curve showed that CTR tended to be linearly associated with STAS after adjusting for sex, age, BMI. The X-abscissa represented the CTR value, and the Y-ordinate represented the risk of primary tumor STAS. The solid black line represented CTR was linearly associated with STAS, and the black dotted lines above and below represent the 95% CIBack to article page