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Abstract For the quantification of rotating frame relaxation times, the T 2ρ relaxation pathway plays an essential role. Nevertheless, T 2ρ imaging has been studied only to a small extent compared with T 1ρ , and preparation techniques for T 2ρ have so far been adapted from T 1ρ methods. In this work, two different preparation concepts are compared specifically for the use of T 2ρ mapping. The first approach involves transferring the balanced spin‐locking (B‐SL) concept of T 1ρ imaging. The second and newly proposed approach is a continuous‐wave Malcolm‐Levitt (CW‐MLEV) pulse train with zero echo times and was motivated from T 2 preparation strategies. The modules are tested in Bloch simulations for their intrinsic sensitivity to field inhomogeneities and validated in phantom experiments. In addition, myocardial T 2ρ mapping was performed in mice as an exemplary application. Our results demonstrate that the CW‐MLEV approach provides superior robustness and thus suggest that established methods of T 1ρ imaging are not best suited for T 2ρ experiments. In the presence of field inhomogeneities, the simulations indicated an increased banding compensation by a factor of 4.1 compared with B‐SL. Quantification of left ventricular T 2ρ time in mice yielded more consistent results, and values in the range of 59.2–61.1 ms (R 2 = 0.986–0.992) were observed at 7 T.
Gram et al. (Mon,) studied this question.