Fig. 2
![Fig. 2](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs13089-022-00284-4/MediaObjects/13089_2022_284_Fig2_HTML.png)
Color Doppler twinkling artifact to visualize the angiocath and cryoprobe positioning. The images belong to a 77-year-old female (Figures A and B) and a 63-year-old male (Figures C and D) undergoing lobectomy by u-VATS. A Contour of the angiocath catheter (without internal stylet) is visible as a hypoechoic line highlighted by adjusting US contrast. B Injection of local anesthetic makes angiocath contour evident by the twinkling artifact. C Cryoprobe within the angiocath is not visualized despite tilting and US gray-scale image adjustments (faint shadow marked by red arrows). D Twinkling artifact localizing the tip above the pleura