Calculation of Stopping-Power Ratio from Multiple CT Numbers Using Photon-Counting CT System: Two- and Three-Parameter-Fitting Method. - Sung Hyun Lee; Naoki Sunaguchi; Akie Nagao; Yoshiyuki Hirano; Hiroshi Sakurai; Yosuke Kano; Masami Torikoshi; Tatsuaki Kanai; Mutsumi Tashiro (Sensors, 2021)