良恶性骨肿瘤的MRI鉴别诊断

目的：通过MRI表现与病理学的对照研究，寻找良恶性骨肿瘤的MRI鉴别诊断征象。材料与方法回顾手术病理证实典型的良恶性骨肿瘤156例，其中良恶性骨肿瘤各78例，（已剔除良恶性交界性肿瘤或侵袭性肿瘤，如韧带样纤维瘤、骨巨细胞瘤等），进行MRI征象及病理学对照，找出良恶性骨肿瘤的鉴别点。全部病例平扫采用包括T1WI、T2WI、T2WI脂肪抑制序列、扩散成像（DWI）。81例行增强扫描采用T1WI。对各种征象在良恶性骨肿瘤中的出现率做统计学分析。结果骨骼为中心的软组织肿块98.5%（64/65）为恶性，1.5%（1/65）为良性，两者有显著性差别（u=2.98，P〈0.01）。肿瘤边界清楚者47.6%（39/82）为恶性，52.4%（43/82）为良性，两者无显著性差别（u=1.45，P〉0.05）。DWI高信号者，51.6%（65/126）出现于恶性骨肿瘤，48.4%（61/126）出现于良性骨肿瘤，两者无显著性差别（u=1.27，P〉0.05）。有肿瘤周围水肿者66.7%（60/90）为恶性，33.3%（30/90）为良性，两者有显著性差异（u=2.65，P〈0.05）。出现放射状骨膜反应与骨膜三角者93.8%（45/48）为恶性，6.2%（3/48）为良性，两者有显著性差异（u=2.83，P〈0.01）。病变区域明显强化者，71.0%（49/69）出现于恶性骨肿瘤，29.0%（20/69）出现于良性骨肿瘤，两者有显著性差别（u=2.33，P〈0.05）。结论骨内病变周围软组织肿块是恶性骨肿瘤的可靠征象。放射状骨膜反应与骨膜三角强烈提示恶性骨肿瘤，少数情况下也可见于良性肿瘤。异常信号边界清楚与否、病变周围水肿、DWI高信号对骨肿瘤良恶性鉴别意义不大。病变区域明显强化者，以恶性骨肿瘤居多。

The differential diagnosis between benign and malignant bone tumors

Objective：To ifnd out the speciifc signs of differential diagnosis between benign and malignant bone tumors by comparing study of MR and pathology. Materials and Methods：Review 156 cases of bone tumors that are proved by surgical procedure and pathology, which include 78 cases of benign and malignant bone tumors respectively （borderline and aggressive tumors like giant cell tumor and desmoplastic ifbroma are excluded from the study）. The MRI signs were compared with pathological results, the different points between malignant and benign tumors were detected. All the 156 cases were performed MR plain scan using T1WI, T2WI, T2WI with fat suppression and DWI sequences. 81 cases were performed MR enhanced scan using T1WI. The occurrence rates of all the signs in benign and malignant bone tumors are analyzed statistically. Results：Abnormal signals inside bone together with solid soft tissue mass around, 98.5%（64/65） were found in malignant bone tumors, 1.5%（1/65） were found in benign bone tumors, the difference between the two was obvious （u=2.98, P〈0.01）. Lesions with clear margin, 47.6%（39/82） were malignant, 52.4% （43/82） were benign, there was no demonstrated difference between the two （u=1.45, P〉0.05）. DWI high signal 51.6%（65/126） was found in the malignant, 48.4%（61/126） in the benign, there was no signiifcant difference between the two （u=1.27, P〉0.05）. Edema around the tumor, 66.7%（60/90） appeared in the malignant, 33.3%（30/90） appeared in the benign, the difference between the two was obvious （u=2.65, P〈0.05）. Radial periosteal reaction and Codman triangle：93.8%（45/48） were displayed in malignant, 6.2%（3/48） were shown in benign bone tumors, the difference between the two was obvious （u=2.83, P〈0.01）. Remarkable enhancement 71.0%（49/69） demonstrated in the malignant, 29.0%（20/69） in the benign, signiifcant difference existed between the two （u=2.33, P〈0.05）. Conclusions：The reliable sign of malignant bone tumors