Abstract: BACKGROUND: Although the clinical manifestations of spinal tuberculosis and Brucella spondylitis are similar, the treatment options are different, and traditional imaging examinations are difficult to accurately distinguish them. Diffusion-weighted imaging can quantify the diffusion differences of water molecules in tissues through apparent diffusion coefficient, which may provide a new way for early identification. However, the correlation between apparent diffusion coefficient and inflammatory markers under different diffusion sensitivity coefficients is not clear.
OBJECTIVE: To explore the clinical value of diffusion-weighted imaging with different diffusion sensitivity coefficients in the diagnosis of spinal tuberculosis and Brucella spondylitis, and to analyze the correlation between apparent diffusion coefficient and inflammatory indicators.
METHODS: Sixty patients with spinal tuberculosis and 60 patients with Brucella spondylitis who were admitted and diagnosed in Shengjing Hospital Affiliated to China Medical University from June 2021 to June 2024 were randomly selected as the research objects. Among them, there were 35 males and 25 females in the spinal tuberculosis group, with an average age of (53.36±5.45) years. There were 38 males and 22 females in the Brucella spondylitis group, with an average age of (55.47±6.43) years. The area under the curve was used to evaluate the diagnostic value of diffusion-weighted imaging-apparent diffusion coefficient under different diffusion sensitivity coefficients in differentiating spinal tuberculosis from Brucella spondylitis. Pearson correlation analysis was used to test the relationship between variables. The apparent diffusion coefficients between operator A and operator B were compared using a paired t-test. The intraclass correlation coefficient was used to analyze the consistency of measurement between different operators and the same operator.
RESULTS AND CONCLUSION: (1) There were significant differences in erythrocyte sedimentation rate, C-reactive protein, white blood cell level, and the distribution of lumbar and thoracic vertebrae involved between the two groups (P < 0.05). Spinal tuberculosis was most likely to affect the lumbar and thoracic vertebrae, and Brucella spondylitis was most likely to affect the lumbar spine. (2) The apparent diffusion coefficients of different vertebral bodies in spinal tuberculosis group were significantly higher than those in Brucella spondylitis group under different diffusion sensitivity coefficients (P < 0.05). In the same group, the apparent diffusion coefficient of lesion vertebral body and paravertebral abscess was significantly different under different diffusion sensitivity coefficients (P < 0.05). (3) When the diffusion sensitivity coefficient was 400 s/mm2, the apparent diffusion coefficient had the highest differential diagnostic efficacy. The sensitivity was 95.00% and the specificity was 96.67%. (4) The intraclass correlation coefficients of diffusion weighted imaging-apparent diffusion coefficient in patients with spinal tuberculosis and patients with Brucella spondylitis by different operators were all greater than 0.75. (5) Pearson correlation analysis showed that the apparent diffusion coefficient of the diseased vertebral body under different diffusion sensitivity coefficients (1.03×10-3-1.49×10-3 mm2/s) 
was significantly correlated with erythrocyte sedimentation rate, C-reactive protein, and white blood cell level (P < 0.001). (6) It is concluded that diffusion weighted imaging is a simple and stable method for the detection of spinal tuberculosis and Brucella spondylitis. When the diffusion sensitivity coefficient is 400 s/mm2, the apparent diffusion coefficient of diffusion weighted imaging has the highest diagnostic efficiency for the differentiation of spinal tuberculosis and Brucella spondylitis, and the apparent diffusion coefficient of the diseased vertebral body under different diffusion sensitivity coefficients is closely related to the state of inflammation.

Key words: spinal tuberculosis, Brucella spondylitis, diffusion-weighted imaging, diffusion sensitivity coefficient, inflammatory state