Response to Letter to the editor: Interrater Reliability of Ultrasound in the Diagnosis of Sialolithiasis: Methodological Issues. Interrater Reliability of Ultrasound: Methodological Issues - Goncalves, Miguel; Mantsopoulos, Konstantinos; Schapher, Mirco Lothar; Iro, Heinrich; Koch, Michael (Ultraschall in der Medizin - European Journal of Ultrasound, 2019)