An injector head (1) with rotation mechanism allows selection between a state in which a syringe (510A, 510B) assumes a priming orientation with a through hole (512) of the syringe (510A, 510B) positioned upper than the injector head body (100), and a state in which the syringe (510A, 510B) assumes a contrast agent injectable orientation with the through hole (512) of the syringe (510A, 510B) positioned lower than the injector head body (100).
