表观扩散系数值在区分肌肉骨骼系统良、恶性肿瘤中的作用

目的 探讨ADC值在区分肌肉骨骼系统肿瘤良恶性中的作用.方法 对33例患有肌肉骨骼系统肿瘤的患者进行MR常规T1加权,T2加权,压脂T2加权检查,以及3D Fast SPGR动态增强成像.MR扩散加权成像采用SS-EPI序列,b值分别取0、700 s/mm2,在动态增强扫描图像上强化明显的区域作为扩散加权成像图上的感兴趣区,测定肿瘤的ADC值.结果 在33例肿瘤中,良性肿瘤为17例,平均ADC值为(1.54±0.35)×10-3mm2/s,恶性肿瘤共有16例,平均ADC值为(1.45±0.45)×10-3mm2/s,二者之间无显著性差异(P>0.05).在33例病例中,共有6例软骨类肿瘤,平均ADC值(1.945±0.51)X10-3mm2/s;非软骨类肿瘤共有27例,平均ADC值(1.41±0.29)×10-3mm2/s,二者之间有显著差异(P<0.05).除1例软骨类肿瘤外,所有软骨类肿瘤的ADC值均大于2.0×10-3mm2/s.结论 以MR动态增强图像来选取DWI图像上肿瘤的感兴趣区(ROI)而测得的ADC值不能区分肌肉骨骼系统肿瘤的良恶性;但是高ADC值(>2.0×10-3mm2/s)对诊断软骨类肿瘤有一定价值.

Value of apparent diffusion coefficient in MR diffusion-weighted imaging for differential diagnosis of benign and malignant musculoskeletal tumors

Objective The purpose of this study was to determine whether the apparent diffusion coefficient (ADC) in diffusion-weighted imaging of MRI was useful for differential diagnosis of benign and malignant musculoskeletal tumors. Methods Thirty-three patients with musculoskeletal tumors underwent 1.5T conventional T1 weighted, T2 weighted, fat-suppressed T2 weighted, and dynamic-enhanced 3D Fast SPGR imaging to identify the lesions. Diffusion weighted images of the region of interest (ROI) were acquired by using a SS-EPI sequence with b values of 0 and 700 s/mm². The ROIs on the diffusion-weighted images were selected as the maximal enhanced areas in the dynamic-enhanced images, and the ADC values were calculated. Results There were 17 benign tumors and 16 malignant tumors. The mean ADC values were (1.54±0.35)×10^-3 mm² /s and (1.45±0.45)×10^-3 mm² /s for benign tumors and malignant tumors, respectively. The difference was not significant (P>0.05). There were 6 cartilaginous tumors and 27 non-cartilaginous tumors. The mean ADC values were (1.94±0.51)×10^-3 mm²/s for cartilaginous tumors and (1.41±0.29)×10^-3 mm²/s for non-cartilaginous tumors, the difference was significant (P<0.05). Five patients with cartilaginous tumors had ADC values higher than 2.0×10^-3 mm²/s. Conclusion The ADC values are not useful for differential diagnosis of benign and malignant musculoskeletal tumors. When the ADC value is higher than 2.0×10^-3 mm²/s, there is an indication for cartilaginous tumors.