Method for generating a magnetic resonance synthetic computer tomography image

A method for generating a contrast image using MRI comprising a three-echo steady state free precession, SSFP, sequence, the method comprising:

• generating a pulse train of excitation pulses having a repetition time;
• generating between two subsequent excitation pulses of the pulse train a first S+ echo;
• a second S+ echo and a first S− echo;
• sampling between the two subsequent excitation pulses the first S+ echo;
• the second S+ echo and the first S− echo;
• generating the contrast image based on the sampled first S+ echo, the sampled second S+ echo and the sampled first S− echo;
• wherein the contrast image comprises a synthetic Computer Tomography, CT, image, and
• wherein the method comprises, between the two subsequent excitation pulses,
• generating a readout gradient of the first S+ echo and a readout gradient of the second S+ echo, wherein the readout gradients of the first S+ echo and second S+
• echo have opposite polarities, and wherein a time integral of the readout gradient of the first S+ echo and a time integral of the readout gradient of the second S+ echo have a same absolute value,
• generating a readout gradient of the first S− echo,
• wherein the readout gradient of a latest of the first and second S+ echo's and the readout gradient of the first S− echo have a same polarity and a same value of the time integral,
• generating a dephasing gradient in a readout direction before an earliest of the first and second S+ echo's, and
• generating a rephasing gradient in the readout direction after the first S− echo, wherein a time integral of the readout gradients, the dephasing gradient and the rephasing gradient over the repetition time provides for one cycle of dephasing per voxel.

A control device for controlling a magnetic resonance imaging apparatus, the control device configured to control the magnetic resonance imaging apparatus to:

• generate a pulse train of excitation pulses having a repetition time;
• generate between two subsequent excitation pulses of the pulse train a first S+ echo;
• a second S+ echo;
• a first S− echo;
• and a second S− echo;
• sample between the two subsequent excitation pulses the first S+ echo;
• the second S+ echo;
• the first S− echo;
• and the second S− echo;
• and
• generate a contrast image based on the sampled first S+ echo, the sampled second S+ echo, the sampled first S− echo, and the sampled second S− echo,
• wherein the contrast image comprises a synthetic Computer Tomography, CT, image, and
• wherein the control device is further configured to control the magnetic resonance imaging apparatus to, between the two subsequent excitation pulses,
• generate a readout gradient of the first S+ echo and a readout gradient of the second S+ echo, wherein the readout gradients of the first S+ echo and second S+ echo have opposite polarities, and wherein a time integral of the readout gradient of the first S+ echo and a time integral of the readout gradient of the second S+ echo have a same absolute value,
• generate a readout gradient of the first S− echo and a readout gradient of the second S− echo, wherein the readout gradients of the first S− echo and second S− echo have opposite polarities, and wherein a time integral of the readout gradient of the first S− echo and a time integral of the readout gradient of the second S− echo have a same absolute value,
• wherein the readout gradient of a latest of the first and second S+ echo's and the readout gradient of an earliest of the first and second S− echo's have a same polarity,
• generate a dephasing gradient in a readout direction before an earliest of the first and second S+ echo's, and
• generate a rephasing gradient in the readout direction after a latest of the first and second S− echo's,
• wherein a time integral of the readout gradients, the dephasing gradient and the rephasing gradient over the repetition time provides for one cycle of dephasing per voxel.