Correction to: On the reproducibility of expert-operated and robotic ultrasound acquisitions. - Risto Kojcev; Ashkan Khakzar; Bernhard Fuerst; Oliver Zettinig; Carole Fakhry; Robert DeJong; Jeremy Richmon; Russell H. Taylor; Edoardo Sinibaldi; Nassir Navab (Int. J. Comput. Assist. Radiol. Surg., 2019)