Respiratory-Gated MRgHIFU in Upper Abdomen Using an MR-Compatible In-Bore Digital Camera
Figure 4
Thermal ablation with fixed focus, intercostal sonication in sheep liver and semichronic followup. K: kidney; L: liver; R: ribs; W: water; (a) and (b) transverse and, respectively, coronal MR thermometry at the sonication end point (40 sec time base), for the respiratory-gated sonication and MR acquisition. FOV is 128 mm square and a colour code for the measured temperature elevation is provided (range of +5°C to +16°C). (c) and (d) MPR sagittal and transverse, respectively, from isotropic 3D VIBE after contrast agent injection (early phase) at day 7 after treatment, shown FOV = 300 mm. (e) and (f) The frames (c) and (d), respectively, zoomed-in by a factor of 4. (g) Gross pathology after 3 weeks of formalin fixation of the liver tissue, shown , sagittal slice. (h) HES microscopic staining, using the same distance scale as frame (f). Note the inset zoom-in by a factor of 3 (the upper right corner), demonstrating a very sharp transition margin between ablated and normal tissue, in the order of 100 microns.
