Simultaneous single‐quantum and triple‐quantum‐filtered MRI of 23Na (SISTINA)

The low MR sensitivity of the sodium nucleus and its low concentration in the human body constrain acquisition time. The use of both single-quantum and triple-quantum sodium imaging is, therefore, restricted. In this work, we present a novel MRI sequence that interleaves an ultra-short echo time radial projection readout into the three-pulse triple-quantum preparation. This allows for simultaneous acquisition of tissue sodium concentration weighted as well as triple-quantum filtered images. Performance of the sequence is shown on phantoms. The method is demonstrated on six healthy informed volunteers and is applied to three cases of brain tumors. A comparison with images from tumor specific O-(2-[18F]fluoroethyl)-L-tyrosine positron emission tomography and standard MR images is presented. The combined information of the triple-quantum-filtered images with single-quantum images may enable a better understanding of tissue viability. Future studies can benefit from the evaluation of both contrasts with shortened acquisition times.