MR imaging findings of osteosarcomas treated with high intensity focused ultrasound / 中华放射学杂志

ABSTRACT

Objective To evaluate the usefulness of MR imaging in follow-up of osteosarcomas treated with high intensity focused ultrasound (HIFU). Methods The images of nonenhanced and multiphase gadolinium-enhanced MR imaging before and after HIFU treatment in 16 patients with osteosarcomas pathologically confirmed were interpreted prospectively and correlated with the results of ~ 99mTc-MDP bone scan. Results The results of HIFU in 14 osteosarcomas were evaluated correctly. Before HIFU, 16 osteosarcomas demonstrated hypointensity on T1WI and heterogenous hyperintensity on T2WI and obvious enhancement during capillary and delayed phases and abnormal radioactivity accumulation were detected.One to Four weeks after HIFU treatment, the osteosarcomas became slightly hyperintense on T1WI and heterogenously hyperintense on T2WI, and no enhancement during capillary and delayed phase was noted. There was a clear boundary presenting between the targeted and untreated areas, and abnormal radioactivity accumulation disappeared. Both the signal intensity on T2WI and the tumor size reduced gradually after HIFU treatment 3 to 25 months. Conclusion HIFU is an effective local therapy for osteosarcomas, and MRI can accurately evaluate the efficacy of HIFU.