Relaxometry phantoms: Are there alternatives to paramagnetic additives?

Phantoms used for relaxometry usually consist of a gelling agent doped with paramagnetic salt. However, since the use of paramagnetic additives can be disadvantageous for certain purposes, there is a great interest in finding other suitable substances. In this work, soy-lecithin-agar gels are presented and evaluated as an alternative phantom material for the construction of relaxometry phantoms with tissue-like relaxation times. They were found to work quite well. Soy-lecithin-agar gels are easy to prepare and allow independent adjustment of T1 and T2. Relaxation times of different tissues (muscle, liver, pancreas, kidney) could be successfully mimicked.