表观扩散系数和分数各向异性定量研究在布鲁斯菌脊柱炎诊断中的价值

目的 比较治疗前不同时期布鲁斯菌脊柱炎(BS)与正常对照组表观扩散系数(ADC)值和分数各向异性(FA)值差异,同时评价治疗前、治疗后不同时间点的ADC值和FA值变化。方法 53例经常规磁共振成像(MRI)检查疑似为BS患者,后经血清学实验确诊为BS患者。对BS患者进行常规MRI和扩散张量成像扫描后测量ADC值、FA值。采用独立样本t检验比较各期BS组与正常对照组、各期BS组间ADC值和FA值。采用重复测量方差分析比较治疗前与治疗后不同测量时间点ADC值及FA值。结果 FA图显示BS彩码不同于正常对照组,BS治疗后FA图彩码信号增高。急性期组、亚急性期组及慢性期组ADC值分别为(1.45±0.02)×10 ^-3 mm ²/s、(1.35±0.03)×10 ^-3 mm ²/s、(1.26±0.05)×10 ^-3 mm ²/s,均高于正常对照组的(1.06±0.09)×10 ^-3 mm ²/s(t=2.538,P=0.009;t=1.998,P=0.032;t=1.575,P=0.004),FA值分别为0.55±0.02、0.65±0.03、0.71±0.04,均低于对照组的0.78±0.02(t=2.440,P=0.012; t=1.847,P=0.041;t=2.102,P=0.003)。重复测量分析显示,急性期组、亚急性期组和慢性期组治疗前和治疗后不同测量时间点ADC值和FA值差异均有统计学意义(ADC值分别为:F=12.100,P<0.001;F=8.439,P=0.005;F=9.704,P=0.004。FA值分别为:F=7.080,P=0.002;F=6.607,P=0.003;F=8.868,P=0.001),治疗后不同测量时间点ADC值低于治疗前或治疗后前一个时间点(F=332.14,P<0.001),FA值高于治疗前或治疗后前一个时间点(F=134.26,P<0.001)。结论 FA图彩码能够直观显示BS和正常椎体差异,同时能够显示治疗前、后彩码变化情况,ADC值和FA值能量化不同时期BS与正常椎体的差异,亦能量化BS病变椎体治疗前、后变化情况,尤其在治疗后BS患者恢复情况下,能够评估常规MRI难以显示微观水肿变化情况,因此,扩散张量成像有望成为评价BS疗效的客观指标。

Values of Apparent Diffusion Coefficient and Fractional Anisotropy in the Diagnosis of Brucella Spondylitis

Objective To compare the differences in apparent diffusion coefficient (ADC) and fractional anisotropy (FA) between brucella spondylitis (BS) groups at different stages before treatment and the normal control group and to evaluate the change trend of ADC value and FA value at different time points before and after treatment. Methods Totally 53 patients suspected of BS by conventional magnetic resonance imaging (MRI) and later confirmed as BS patients by serological tests were enrolled in this study. These patients underwent conventional MRI and diffusion tensor imaging scans,and the ADC value and FA value were measured. Independent sample t test was used to compare the ADC value and FA value between the BS group and the control group,the ADC value and FA value between the BS group at each stage. Repeated measurement ANOV was used to compare the ADC values and FA values at different time points before and after treatment. Results FA imaging showed that the color code of BS was different from that of the normal control group,and the color code of FA imaging showed increased singal. The ADC values of BS in the acute,subacute,and chronic stages (1.45±0.02)×10 ^-3 mm ²/s,(1.35±0.03)×10 ^-3 mm ²/s,(1.26±0.05)×10 ^-3 mm ²/s,respectively] were significantly higher than those in the control group (1.06±0.09) ×10 ^-3 mm ²/s](t=2.538,P=0.009;t=1.998,P=0.032;t=1.575,P=0.004),and the FA value (0.55±0.02,0.65±0.03,0.71±0.04,respectively) were significantly lower than those of the control group (0.78±0.02) (t=2.440,P=0.012; t=1.847,P=0.041;t=2.102,P=0.003). Repeated measurement analysis showed that there were statistically significant differences in ADC values and FA values at different time points before and after treatment in the acute,subacute,and chronic stages (ADC:F=12.100,P<0.001;F=8.439,P=0.005;F=9.704,P=0.004,respectively;FA:F=7.080,P=0.002;F=6.607;P=0.003;F=8.868,P=0.001,respectively). The ADC values at different time points after treatment were significantly lower than those before treatment or at a previous time point after treatment (F=332.14,P<0.001),and the FA values were significantly higher than those before treatment or at a previous time point after treatment (F=134.26,P<0.001). Conclusions FA color code can intuitively display differences in BS and normal vertebral bodies and show change of color code before and after treatment. Also,the ADC values and FA values can quantitatively reveal differences between BS and normal vertebral body in different time points and quantify BS vertebral lesion changes before and after treatment. In particular,in BS patients who are recovering from treatment,it can quantify microscopic edema. Therefore,diffusion tensor imaging may be useful objective indicator in evaluating the effectiveness of a specific treatment for BS.