MRI Presentation of Malignant Bone Tumors After High-intensity Focused Ultrasound Therapy

摘要

Objective The purposes of this paper are to explore the MRI changes of malignant bone tumors before and afterrnhigh-intensity focused ultrasound (HIFU) therapy, and to investigate the possibility of MRI as a method to evaluate thernshort-term effect after HIFU treatment of malignant bone tumors.rnMethods A totals of 35 patients with malignant bone tumors underwent MRI examination before and two weeks afterrnHIFU, and signal changes of plain T1WI, T2WI and Gd-DTPA enhanced T1WI were evaluated. Patient data followed: 21rnmale and 14 female aging 5-70 (mean 19) years old; 31 were primary bone tumor, surgical stage: 23 at stage Ⅱb and 8 at atrnⅢ; 4 cases of bone metastases, TNM stage: 2 at stage Ⅳ and 2 at stage Ⅳb; pathological types: 21 typical osteosarcoma, 1rnjuxtacortical osteosarcoma, 1 parosteal osteosarcoma, 2 chondrosarcoma, 3 Ewing's sarcoma, 2 bone metastases from lungrncancer, 2 from renal clear cell carcinoma and 3 with no clear histological sources.rnResults After HIFU therapy, signals of plain T1 and T2 in the treated region became shorter, and no intensification wasrnfound in enhanced images. There was a thin intensification tape around the treated region and a clear and sharp marginrnbetween the treated and untreated region.rnConclusions Signal changes of MRI before and after HIFU are rather apparent. It is possible to use MRI as a noninvasivernmethod to evaluate short-term effect of HIFU therapy.