In Vivo Characterization of Tissue Thermal Properties of the Kidney by HIFU Local Hyperthermia Under MR-Thermometry with Modulation of the Arterial Flow

Franois Cornelis^1,2, Nicolas Grenier^1,2, Chrit Moonen¹, Bruno Quesson¹

The purpose was to evaluate in vivo quantitatively the tissue thermal properties (perfusion, absorption, thermal diffusivity). A total of 42 localized HIFU heating were performed in the kidney of 6 pigs monitored by MR thermometry. Arterial flow was modulated by an angioplasty balloon in the aorta. The resulting temperature data were analyzed with the Bio Heat Transfer model and an excellent correspondence was observed. Absorption and thermal diffusivity were found independent from the flow, whereas perfusion was directly linked to arterial flow. This method could improve the quality of the planning of the non invasive therapy with MR guided HIFU.