Comparison of the Variability of Hepatic Load Quantification in Iron and Fat Estimated by MRI at 1.5 and 3 Tesla

Quantification of hepatic iron by MRI is validated at 1.5 Tesla on a small number of subjects with some discrepancies between the two most used techniques (liver to muscle ratio or calculation of the decay rate of the T2 * signal). Since the initial publications at 1.5 Tesla, new technical innovations have emerged which can allow better quantification. Recently, the investigators have applied these innovations to Rennes and have validated (SURFER study) the possibility of making a quantification of iron and fat on two 3 Tesla devices with good results in a single apnea acquisition. But it is not uncommon to have, in a structure, different magnetic field devices, and it is important to ensure that the results are transposable. It is also crucial for multicentre or cohort studies to ensure consistency. It is therefore proposed to compare the results of two examinations at 1.5 and 3 Tesla obtained on the same day on a series of 80 patients.

Inclusion criteria

• Adult 18 years of age or older;
• Having an MRI indication of iron and fat quantification;
• Benefiting from social security;
• Having given a free, informed and written consent.

Exclusion criteria

Related to MRI

• Implantable cardiac pacemaker or defibrillator;
• Non-MRI cardiac valve compatible;
• Clips, stents, coils, etc ... no MRI compatible;
• Cochlear implants;
• Neuronal or peripheral stimulator;
• Foreign bodies metallic intra orbital or encephalic, foreign body close to the eyes, wound by metallic lash (war, ball);
• Endoprostheses placed for less than 4 weeks and osteosynthesis materials placed less than 6 weeks old;
• Claustrophobia;
• Pumps, tattoos, permanent make-up, intrauterine device, patches;
• Metallic, magnetic, non-removable material and close to the analysis field.

Other criteria

• unstable hemodynamic status, acute respiratory failure, general precarious condition or a need for continuous monitoring incompatible with MRI constraints;
• Persons subject to major legal protection (safeguarding justice, guardianship, trusteeship), persons deprived of liberty.
• Known pregnancy, breastfeeding.