关键词: 肌肉骨骼系统, 肿瘤, 磁共振成像, 诊断

Abstract:

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.

Key words: Musculoskeletal system, Neoplasms, Magnetic resonance imaging, Diagnosis