Competing interests
Jeong Hee Yoon: Honoraria from Accuzen, Bayer and Philips Healthcare. Consulting fee from Bayer. Jeong Min Lee: Grant from Bayer, Bracco, Canon, Central Medical Servis, Dongkuk Pharma, GE Healthcare, Guerbet, Philips Healthcare, Samsung Medison, Siemens Healthineers; Consulting fees from Sansumg medison; Honoraria from Bayer, Claripi, GE Healthcare, Guerbet, Philips Healthcare, Samsung Medison, Siemens Healthineers. Other authors (J.Y.P., S.M.L., E.S.L., J.H.K.) declared no competing interests.