- Workshop presentation
- Open Access
Standardized phantoms for quantitative cardiac MRI
© Keenan et al; licensee BioMed Central Ltd. 2015
- Published: 3 February 2015
- Left Ventricle
- Future Design
- Relaxation Property
- Regular Quality
- Vendor System
To test quantitative cardiac MR sequences, the phantom must mimic both the T1 and T2 relaxation properties in the same sample. The phantom must be stable, preferably for five years, and be reliably produced. Agarose gel is difficult to produce free of air bubbles and has a limited shelf life.
We think the relaxation times can be mimicked using paramagnetic salts and metallic oxides in aqueous solution. By our calculations for 1.5 T, the post-contrast myocardium relaxation properties (T1 ~ 200 ms, T2 ~ 50 ms) can be mimicked using an aqueous solution of 8.32 mM NiCl2 and 0.36 mM MnCl2 or by 0.25 mM Feraheme solution. The pre-contrast myocardium and blood pool relaxation properties are more difficult. Based on experiments in our lab at 1.5 T, the pre-contrast myocardium relaxation properties (T1 ~ 1000 ms, T2 ~ 50 ms) can be mimicked using an aqueous solution of 0.1 mM FeRex. The blood pool relaxation properties (T1 ~ 1500 ms, T2 ~ 200 ms) can likely be mimicked using a combination of NiCl2 and Al2O3. Our work using Al2O3 is at a preliminary stage. The nano-iron solutions (Feraheme and FeRex) do have stability and susceptibility concerns that need to be explored further.
Future design could be an injection molded object with three compartments to better match the geometry of the left ventricle and healthy to diseased myocardium wall thickness (6 to 15 mm). In addition, a chest cavity material could surround future designs for proper loading of the coils.
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