Method for performing an imaging examination of a patient by means of a computer tomograph, comprising the steps: - capturing a respiratory movement of the patient, wherein a respiration-correlated parameter T cycle which describes a time duration of a respiratory cycle of the respiratory movement is determined from the respiratory movement of the patient, - specifying a measurement region of the imaging examination, wherein the measurement region has at least one z-position, - automatically calculating at least one measurement parameter in accordance with the respiratory movement, wherein the respiration-correlated parameter T cycle is used as an input parameter for the automatic calculation of the at least one measurement parameter, such that when the imaging examination is performed in accordance with the at least one measurement parameter, projection data at the at least one z-position can be captured over the complete time duration of the respiratory cycle, and - performing the imaging examination of the patient in accordance with the at least one measurement parameter in the measurement region by means of the computer tomograph, wherein the projection data is acquired which depicts the respiratory cycle of the patient at the at least one z-position over the complete time duration of the respiratory cycle, wherein the automatic calculation of the at least one measurement parameter comprises calculating a tube current I tube of the computer tomograph during the imaging examination in such a way that the tube current I tube is indirectly proportional to the respiration-correlated parameter T cycle, wherein an overall dose I ges according to a product from the tube current I tube is kept constant with the respiration-correlated parameter T cycle. - capturing a respiratory movement of the patient, wherein a respiration-correlated parameter T cycle which describes a time duration of a respiratory cycle of the respiratory movement is determined from the respiratory movement of the patient, - specifying a measurement region of the imaging examination, wherein the measurement region has at least one z-position, - automatically calculating at least one measurement parameter in accordance with the respiratory movement, wherein the respiration-correlated parameter T cycle is used as an input parameter for the automatic calculation of the at least one measurement parameter, such that when the imaging examination is performed in accordance with the at least one measurement parameter, projection data at the at least one z-position can be captured over the complete time duration of the respiratory cycle, and - performing the imaging examination of the patient in accordance with the at least one measurement parameter in the measurement region by means of the computer tomograph, wherein the projection data is acquired which depicts the respiratory cycle of the patient at the at least one z-position over the complete time duration of the respiratory cycle, wherein the automatic calculation of the at least one measurement parameter comprises calculating a tube current I tube of the computer tomograph during the imaging examination in such a way that the tube current I tube is indirectly proportional to the respiration-correlated parameter T cycle, wherein an overall dose I ges according to a product from the tube current I tube is kept constant with the respiration-correlated parameter T cycle. wherein the automatic calculation of the at least one measurement parameter comprises calculating a tube current I tube of the computer tomograph during the imaging examination in such a way that the tube current I tube is indirectly proportional to the respiration-correlated parameter T cycle, wherein an overall dose I ges according to a product from the tube current I tube is kept constant with the respiration-correlated parameter T cycle.