In Vivo Evaluation of MRgHIFU Volumetric Sonication Using Interleaved Electronic-And-Mechanical Displacement of Focus

Lorena Petrusca^1,2, Jacqueline Ngo¹, Vincent Auboiroux^1,2, Francois Cotton, ²³, Jean-Yves Chapelon¹, Rares Salomir¹

Phased-array HIFU transducer under MR-guidance can bring important improvements in actual clinical strategy for prostate cancer treatment. The performances of a MR-compatible transrectal HIFU device with 16 circular rings were in vivo investigated on rabbit thigh. Dual-mode displacements of the focus was performed: electronically, along the ultrasound propagation axis and mechanically XZ 2D-translations and rotation around B0. Online fast MR-thermometry in 2 orthogonal planes, MRI assessment 5 days after the treatment and the histological analyze showed that a homogenous lesion was induced in the predefined zone. Dual-mode sonication paradigm offer the possibility to induce the lesion desired shape in a reasonable time period, and minimizing the side-effects.