Fig. 4
Multimodality imaging of MR-HIFU ablation. a–c T 2 -weighted MRI of femurs before (a), at 7 days (b), and at 1 month (c) after ablations. b Edema was observed around the treated bone while mixed hypo- and hyper-intense signal was present in the intramedullary space. b–c, f, i Yellow arrows show lines with hypo-intense signal, which are similar to cortical bone, in the intramedullary space. d–i T1-weighted MRI prior to (d–f) and after (g–i) contrast agent injections. h Non-perfused region was observed around the treated bone after contrast agent administration. i Hypo-intense region in the intramedullary space suggest bone marrow damage. j–l SPECT/CT images before (j) and at 7 days (k) as well as 1 month (l) after HIFU ablation. k–l Areas with increased 99mTc-MDP accumulation (yellow arrows) were detected within the intramedullary space and on the cortical surface. m–o μCT images of femurs before (m) and after (n–o) HIFU ablation. n–o Woven bone formation (yellow arrow) was observed in the intramedullary space at 7 days and 1 month post treatments. o Cortical thickening (white arrows) was present at 1 month after treatments