Measurement of T2 transversal relaxation time by magnetic resonance has a major interest in cardiac imagery. It has been initially used for quantitative evaluation of heart viability and more recently for edema characterization. It allows to prematurely detect a cardiac transplant rejection. This technique needs successively around ten FSE sequences during apnea. Weak reproducibility of successive apneas and discomfort of patient limit the precision of this measurement and consequently its use in standard care. The ARTEMIS study method allows the examination during free respiration without prolonging the duration of examination compared to the examination during apnea. Moreover, image processing is simplified and correction of respiratory movements renders results more reliable.

This is a pilot study of evaluation of ARTEMIS technique of image reconstruction. ARTEMIS is a method of MRI image reconstruction for measurements of T2 transversal relaxation. It allows to obtain diagnostic images without movement artifacts.

The primary objective si to show the feasibility of ARTEMIS method for measurement of myocardial T2 relaxation time during free respiration in cardiac transplant patients.

The secondary objective is to collect quantitative data to compare ARTEMIS method of measurement of T2 during free respiration and standard clinical practice during apnea.

Inclusion Criteria:

• To have had a heart transplant, whenever
• To have an MRI scan of heart with measurement of T2 relaxation time (whatever the reason for examination)
• Major
• To be aware and cooperative
• Affiliation to social security plan
• To have given written consent after having received oral and written, clear and intelligible information

Exclusion Criteria:

• All contraindications to MRI (implantable defibrillator, cochlear implant, neurosurgical clip, intraorbital or encephalic metallic foreign body, endoprosthesis installed since less than 4 weeks, osteosynthesis materials installed since less than 6 weeks…)
• Instable hemodynamic status, acute respiratory failure, uncertain general status or necessity of continuous monitoring incompatible with MRI examination
• Minors or being under juridical protection or absence of social security
• Refusal or impossibility of informed consent of patient