Values of Apparent Diffusion Coefficient and Fractional Anisotropy in the Diagnosis of Brucella Spondylitis / 中国医学科学院学报

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. 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 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. 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 mm /s,(1.35±0.03)×10 mm /s,(1.26±0.05)×10 mm /s,respectively] were significantly higher than those in the control group [(1.06±0.09) ×10 mm /s](=2.538,=0.009;=1.998,=0.032;=1.575,=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) (=2.440,=0.012; =1.847,=0.041;=2.102,=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:=12.100,<0.001;=8.439,=0.005;=9.704,=0.004,respectively;FA:=7.080,=0.002;=6.607;=0.003;=8.868,=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 (=332.14,<0.001),and the FA values were significantly higher than those before treatment or at a previous time point after treatment (=134.26,<0.001). 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.

Diffusion Tensor Imaging in Early Diagnosis and Prognostic Prediction of Intervertebral Disc Change in Patients with Brucella Spondylitis / 中国医学科学院学报

Objective To explore the value of fractional anisotropy(FA) and apparent diffusion coefficient(ADC) in the early diagnosis of intervertebral disc change in patients with Brucella spondylitis(BS) and in the assessment of BS disc changes after treatment and to further investigate the imaging features of BS in its acute,subacute,and chronic stages. Methods Totally 60 serologically or pathologically confirmed BS patients who were treated in the First Hospital Affiliated to Hebei North University(n=20) or ZhangJiakou Infectious Diseases Hospital(n=40) were enrolled. BS patients were scanned by CT,magnetic resonance imaging,and diffusion tensor imaging,and the FA and ADC values of the disc were measured using the DTI Fiber Trak package. The FA and ADC values were compared in each period and after treatment. Results The ADC value significantly increased and the FA value significantly decreased in different stages(P<0.01). Six months after treatment,the ADC value was significantly lower than the pre-treatment,and the FA value was significantly increased(P<0.01). The ADC value 12 months after treatment for patients in acute or subacute stage and the FA value 12 months after treatment for patients in all stages were significantly different from those in the 6 month after treatment(P<0.01),and the only exception was that the ADC value in the chronic stage was not significantly different between 12 and 6 month after treatment(P=0.089).Conclusion FA and ADC values are more sensitive than conventional MRI sequences in the diagnosis of BS intervertebral disc change and therefore can be used for the early diagnosis and prognostic prediction.