表观扩散系数值鉴别良恶性骨肿瘤及肿瘤样病变的价值

The role of apparent diffusion coefficient in the differentiation between benign and malignant bone tumors

目的探讨MRDWI的ADC值鉴别良、恶性骨肿瘤及肿瘤样病变的价值。方法对18例良性骨肿瘤及肿瘤样病变和26例恶性骨肿瘤行DWI。采用单激发EPI序列，3个扩散敏感梯度，b值分别为0、500、1000s／mm^2。在ADC图上测量每个病变的最低、最高和整体ADC值。结果良性骨肿瘤及肿瘤样病变的最低ADC值[（1．28±0．49）×10^-3mm^2／s]高于恶性骨肿瘤[（0．92±0．35）×10^-3mm^2／s，t=2．839，P〈0．01]，整体ADC值[（1．62±0．51）×10^-3mm^2／s]也高于恶性骨肿瘤[（1．21±0．36）×10^-3 mm^2／s，t=3．092，P〈0．01]，但两者都有很大重叠。良性骨肿瘤及肿瘤样病变的最高ADC值[（2．02±0．55）×10^-3mm^2／s]与恶性骨肿瘤的最高ADC值[（1．71±0．65）×10^-3mm^2／s]差异无统计学意义（t=1．669，P〉0．05）。去掉以囊腔为主的骨囊肿及动脉瘤样骨囊肿病例，则良性骨肿瘤及肿瘤样病变的最低、最高和整体ADC值分别为（1．11±0．31）×10^-3mm^2／s、（1．88±0．49）×10^-3mm^2／s和（1．45±0．35）×10^-3mm^2／s，与恶性骨肿瘤比较差异无统计学意义（t值分别为1．728、0．964、2．012，P值均〉0．05）。结论ADC值不能鉴别良、恶性骨肿瘤及肿瘤样病变。

Objective To explore the role of apparent diffusion coefficient （ADC） value of diffusion-weighted imaging （DWI） in the differentiation between benign and malignant bone tumors. Methods Echo planar imaging DWI was performed in 18 patients with benign tumor or tumorous lesion and 26 patients with malignant tumor of bone. Three b-values （0, 500 and 1000 s/mm^2） were applied. The lowest, highest, and whole ADC values were measured for each lesion, respectively. Results The lowest ADC values of benign bone tumor[ mean（ 1.28 ± 0.49） × 10^-3 mm^2/s] were significantly higher than that of malignant tumor [ mean （0. 92 ±0. 35） ×10^-3 mm^2/s, t = 2. 839, P 〈 0. 01 1. The whole ADC values of benign bone tumor [ mean （ 1.62 ± 0. 51 ） × 10^-3 mm^2/s ] were significantly higher than that of malignant tumor [mean （1.21 ±0. 36） × 10^-3mm^2/s,t =3. 092,P 〈0. 01]. However, there were much overlapping between benign and malignant bone tumor in the lowest and whole ADC values. There was no significant difference for the highest ADC values between benign [ mean （2. 02 ± 0. 55 ） ×10^-3 mm^2/s] and malignant bone tumor[ mean（ 1.71 ±0. 65 ）×10^-3 mm2/s, t = 1. 669, P 〉 0. 05]. Excluding cases of bone cyst and aneurismal bone cyst, the lowest, highest, and whole ADC values of benign bone tumor was （ 1.11 ± 0. 31 ） × 10^-3mm^2/s, （ 1.88±0. 49 ）× 10^-3 mm^2/s, and （ 1.45±0. 35 ） × 10^-3 mm2/s, respectively. There was no significant difference for the lowest, highest, or whole ADC values between benign and malignant bone tumor （ t = 1. 728, 0. 964, and 2. 012, respectively, P 〉 0. 05 ）. Conclusion ADC value is useless for the differentiation between benign and malignant bone tumors.