A method of operating a magnetic resonance imaging system (10) being connectable to a respiration monitoring means (46) which is configured to provide an output signal (48) whose level represents a respiration state of the subject of interest (20), the method comprising: a step (54) of providing a prospective acquisition scheme for acquiring magnetic resonance images at each respiration state of a set of selected respiration states of the subject of interest (20), the triggering on the selected respiration states being based on predetermined threshold output signal levels of the respiration monitoring means (46), and, during executing magnetic resonance image acquisition pursuant to the prospective acquisition scheme, a step (58) of comparing actual respiration states at which magnetic resonance images were actually acquired, with the selected respiration states according to the prospective acquisition scheme and predetermined ranges of tolerance (52) of the selected respiration states, a step (60) of modifying the prospective acquisition scheme, if one of the actual respiration states lies outside the predetermined range of tolerance (52) of the selected respiration state, and a step (62) of proceeding execution of magnetic resonance imaging acquisition pursuant to the modified prospective acquisition scheme; and a magnetic resonance imaging system (10) comprising a control unit (26) that is configured to carry out steps of an embodiment of such a method.