Volumetric MR-HIFU Ablation of Uterine Fibroids: Factors Influencing Intraprocedural Thermal Parameters

Preprocedural predictors of treatment efficacy will be useful for excluding in advance patients who would not benefit from this treatment, thereby contributing to improved overall clinical outcomes. During ablathermy treatment lost of energy depend of tissue perfusion and thermic diffusion while energy laying depend of tissue absorption coefficient. Study these parameters before treatment could bring important information to the treatment difficulty and its efficacy. The investigators will study and compare fibroid perfusion with dynamic contrast-enhanced magnetic resonance imaging and contrast-enhanced ultrasound (CEUS). CEUS will be performed with contrast agent (SONOVUE). Thermic diffusion could be linked with fibroid stiffness. Fibroid stiffness will be quantified with velocity of shear wave measured by acoustic radiation force impulse (ARFI). Tissue absorption coefficient is correlated with the architecture and the cellularity of the tissue so the investigators think that apparent diffusion coefficient (computed with diffusion weighted imaging) could be correlated with ablathermy efficiency and other intra procedural thermal parameters.