A driving method of SAR-optimized control of a coil array

A control means (7) of a magnetic resonance system controls the coils (6) of a transmit array (4) and a gradient magnet system (3) of the magnetic resonance system in accordance with an excitation pulse (P '). Characterized in an excitation volume (2) of the magnetic resonance system is generated a magnetization that has a first Istinhomogenitat (I2). The controller (7) determines the excitation pulse (P ') based on a start pulse (P) and one in the excitation volume (2) of the magnetic resonance system maximum acceptable inhomogeneity (I *). The start pulse (P) has an overall length of time (T '). In the case that the control device (7) drives the coil (6) of the transmit array (4) and the gradient (3) corresponding to the start pulse (P), in the excitation volume (2) magnetization is created, a second Istinhomogenitat (I1 ) which is smaller than the maximum allowable inhomogeneity (I *). The controller (7) determines an intermediate position (Z) of the start pulse (P), so that the seed pulse (P) in a first pulse part (P1) and a corresponding complementary second pulse part (P2) is divided. The first pulse portion (P1) corresponds to a low-energy part of the start pulse (P), the second pulse part (P2) with a high-energy part of the start pulse (P). Said control means (7) reaches the second pulse portion (P2) in time and compresses it hereby corresponding in amplitude (A). The time-stretched and in amplitude (A), compressed ...