Fig. 4
![Fig. 4](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs13075-018-1686-9/MediaObjects/13075_2018_1686_Fig4_HTML.png)
Comparisons of total skin thickness (TST) evaluated by high-frequency ultrasound in healthy control and patients with systemic sclerosis (SSc) with scales of the modified Rodnan skin score (mRSS). Boxes represent the 25th and 75th percentile of measures, and the median (line within the box) and the minimum and maximum values (whiskers) are shown. TST with mRSS = 0, mRSS = 1 and mRSS = 2 in the patients were all significantly higher than in the controls (P = 0.0012, P <0.0001 and P < 0.0001, respectively). No significant difference was found between patients with mRSS = 3 and the controls (P = 0.0578)