目的：探讨动态增强磁共振成像（dynamic contrast enhanced magnetic resonance imaging，DCE-MRI）的药代动力学参数［如容量转移常数（volume transfer constant，Ktrans）、血管外细胞外容积分数（extravascular extracellular space distribute volume per unit tissue volume, Ve）和返流速率常数（microvascular permeability reflux constant，Kep）］用于肌骨系统肿瘤定性诊断中的可行性。方法： 选择2013年10月至2014年9月来北京积水潭医院就诊的肌骨系统肿瘤患者共34例进行回顾性分析，患者使用1.5T MR扫描仪进行检查，DCEMRI使用脂肪抑制3D VIBE(volumetric interpolated breath-hold exam)序列。根据病理诊断结果，将肿瘤分为良性、交界性及恶性，病灶所在层面的正常肌肉组织作为对照组，对每组肿瘤与对照组的Ktrans、Ve和Kep的差异进行配对t检验，对3组病变数据中的差异进行单因素方差分析，P＜0.05认为差异具有统计学意义。结果： 良性肿瘤Ktrans和Kep值与对照组的差异无统计学意义，而Ve值与对照组比较有所升高。交界性肿瘤的Ktrans和Ve值明显高于对照组，而Kep与对照组差异无统计学意义(P>0.05)。恶性肿瘤的Ktrans、Kep和Ve值明显高于对照组。恶性肿瘤的Ktrans (P<0.001)和Kep (P<0.01)均高于良性和交界性肿瘤，Ve高于良性肿瘤(P<0.05)，而与交界性肿瘤差异无统计学意义(P>0.05)。良性和交界性肿瘤的Ktrans、Kep和Ve值之间的差异无统计学意义(P>0.05)。结论： DCEMRI药代动力学参数Ktrans和Kep可以反映肌骨系统良性、交界性和恶性肿瘤在毛细血管渗透性方面存在的差异，这将有助于肿瘤的定性诊断。

Objective： To investigate the feasibility of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters in differentiating musculoskeletal tumors with different behaviours of pathological findings before therapy. Methods: A total of 34 subjects of musculoskeletal tumors were involved in this retrospective analysis. DCE-MRI was performed using a fat-saturated 3D VIBE (volumetric interpolated breath-hold exam) imaging sequence with following parameters: FA, 10 degree; TR/TE, 5.6/2.4 ms; slice thickness, 4.0 mm with no intersection gap; field of view, 310 mm×213 mm; matrix, 256×178; voxel size, 1.2 mm×1.2 mm×4.0 mm; parallel imaging acceleration factor. The actuation time for the DCE-MRI sequence was 255 s with a temporal resolution of 5 s and 40 image vo-lumes. Using pathological results as a gold standard, tumors were divided into benign, borderline and malignant tumors. Toft’s model was used for calculation of Ktrans (volume transfer constant), Ve (extravascular extracellular space distribute volume per unit tissue volume) and Kep (microvascular permeability reflux constant). Those parameters were compared between the lesions and the control tissues using paired t-tests. The one-way analysis of variance was used to assess the difference among benign, borderline and malignant tumors. P values ＜0.05 difference was statistically significant. Results: Based on the WHO Classification of Tumours of Soft Tissue and Bone(2012) criteria, 34 patients were divided into three groups: 11 for benign tumors, 12 for borderline tumors, and 11 for malignancies. Compared with control tissues, Ktrans and Kep showed no difference, but Ve was increased in benign tumors, Kep showed no diffe-rence, but Ktrans and Ve were increased in borderline tumors,Ktrans, Kep and Ve were increased in malignant tumors. Ktrans (P<0.001) and Kep (P<0.01) were significantly higher in malignant tumors than in benign and borderline tumors, but did not show any difference between benign tumors and borderline tumors. Ve was significantly higher in malignant tumors than in benign (P<0.05), but did not show any difference between malignant and borderline tumors, benign tumors and borderline tumors (P>0.05). Conclusion: DCE-MRI technique is useful to evaluate the pathological behaviour of musculoske-letal tumors. The quantitative analysis of DCE parameters in conjunction with conventional MR images can improve the accuracy of musculoskeletal tumor qualitative analysis.