| Objective To explore the incidence and significance of bone marrow edema associated with malignant bone tumors,quantify the volume of the edema surrouding the lesions,compare it with the tumor and grade the edema,identify its relevance to pathology of different kinds of malignant bone tumors.Methods Magnetic resonance imaging(MRI)data of 218 patients with malignent bone tumors diagnosed by pathology were retrospectively reviewed.Borderline tumors(such as giant cell tumor of bone),cases associated with surgical treatment,radiation therapy and chemotherapy,and skull lesions were excluded from the study.Recurrent cases and those with pathological fractures were also excluded.Bone marrow edema were defined on T2 WI with fat suppression or STIR with fat suppression on MRI in all cases,combining T1 WI to identify the border of the lesion.The maximum diameter of the edema and the lesion were measured in axial,sagittal or coronal section,no matter whether they were in the same section.The extent of edema and the size of the tumors were compared and analyzed.The amount of the edema was graded,grade Ⅰ: edema was present but smaller than the tumor size;grade Ⅱ: edema was equivalent to the tumor size;grade Ⅲ: edema was greater than the tumor size.The analysis of the incidence rate of edema in the malignent bone tumors and the grade of edema relative to the underlying lesion size were performed using Univariate analysis of variance.Result Among 218 cases,there were 137 males and 81 females,with an age range of 6-86years(mean 50.66±19.74 years).The ratio of men to women was 1.69:1.The most commen site was femur which accounted for 46.33%(101/218),tibia accounted for 16.06%(35/218),humerus accounted for11.47%(25/218),the total of three accounted for73.85%(161/218).Of all 218 cases,there were 169 lesions with edema,the total incidence rate of edema was 77.52%(169/218),including 97.5%(39/40)osteosarcoma,86.67%(13/15)chondrosarcoma,33.33%(5/15)myeloma,73.98%(91/123)metastasis,66.67%(4/6lymphoma,75%(3/4)fibrosarcoma.1case of chordoma,there was no obvious edema around it.The others have edema to some extent.The incidence of edema in osteosarcoma was the highest,and myeloma had the lowest incidence of edema.In osteosarcoma,there were 27 grade Ⅰ cases,which accounted for 67.5%(27/40).In chondrosarcoma,there were 12 grade Ⅰ cases,which accounted for 80%(12/15).In metastasis,there were 68 grade Ⅰ cases,which accounted for 55.28%(68/123).In myeloma,there were 3 grade Ⅰ cases,which accounted for 20%(3/15).There were 32 cases with no edema,which accounted for 26.02%(23/123)in metastasis.In myeloma,there were10 cases with no edema,which accounted for 66.67%(10/15).Osteosarcoma was mainly characterized by grade Ⅰ edema,metastasis was mainly characterized by grade Ⅰ and without edema,myeloma was mainly characterized without edema.Of all 169 cases with edema,there were 76.92%(130/169)grade Ⅰ edema,8.88% (15/169)grade Ⅱ edema,14.20%(24/169)grade Ⅲ edema.Of all 218 tumors in this study,grade Ⅰ edema accounted for 59.63%(130/218),without edema was 22.48%(49/218),grade Ⅲ edema was 11.01%(24/218),grade Ⅱ edema was 6.88%(15/218).Grade Ⅰ and without edema accounted for 82.11%.Conclusion Bone marrow edema is a commom finding associated with malignant bone tumors,and they are frequently detected in osteosarcoma,chondrosarcoma,metastasis.If the bone marrow edema surrounding the tumors is smaller than the lesion itself(gradeⅠ edema),the lesion might be malignant. |
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