Figure 3

In vivo ballistic marker in rabbit thigh followed by HIFU sonication. a) - c): T1w 3D (VIBE) images of the ballistic target model, shown in situ just before MRgHIFU sonication. The sagittal (feet first), coronal and axial planes are shown from left to right, respectively. The RF-affixed marker appears as a bright spot. d) - f): Gd-enhanced T1w 3D (VIBE) images 7 days post-treatment of the same animal, showing the necrotic and fibrotic lesion. The multi planar reconstruction crossing point indicates the approximate position of the pre-defined ballistic target model. g) Macroscopic findings corresponding to the same rabbit treatment (3 weeks formalin fixation, followed by toluene bath dehydration and 8 months conservation). The piece was sliced along the sagittal plane (head first) and the dashed contour delineates the ablative lesion. The methylene blue staining is seen to be misaligned with the center of the actual MRgHIFU thermal lesion by approximately 1 cm. Coagulation necrosis showed a complete loss of striation (down in the corner, zoomed view). h) Macroscopic illustration of another rabbit thigh sliced after 3 weeks post mortem formalin fixation. The MRgHIFU volumetric lesion (delineated manually by dots) is here perfectly centered on the ballistic target model, the latter visible as a dark stained spot.