Diagnostic value of diffusion-weighted imaging with different diffusion sensitivity coefficients for spinal tuberculosis and Brucellar spondylitis

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; and 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 at different diffusion sensitivity coefficients in differentiating spinal tuberculosis and Brucella spondylitis. Pearson correlation analysis was used to test the relationships between variables. Paired t-test was used to compare the apparent diffusion coefficients between operator A and B. Intraclass correlation coefficient was used to analyze the consistency of measurements 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 distribution of lumbar and thoracic involvement between the two groups (P < 0.05). Spinal tuberculosis most commonly involved the lumbar and thoracic spine, while Brucella spondylitis most commonly involved the lumbar spine. (2) The apparent diffusion coefficients of the affected vertebral bodies in the spinal tuberculosis group were significantly higher than those in the Brucella spondylitis group at all diffusion sensitivity coefficients (P < 0.05). Within the same group, there were significant differences in apparent diffusion coefficients between the affected vertebral body and paravertebral abscess at different diffusion sensitivity coefficients (P < 0.05). (3) The diagnostic efficiency of apparent diffusion coefficient was the highest at a diffusion sensitivity coefficient of 400 s/mm2, with a sensitivity of 95.00% and specificity of 96.67%. (4) The intraclass correlation coefficients of diffusion-weighted imaging-apparent diffusion coefficient between different operators for both spinal tuberculosis and Brucella spondylitis were greater than 0.75. (5) Pearson correlation analysis showed that the apparent diffusion coefficients of the affected vertebral bodies at different diffusion sensitivity coefficients (1.03×10-3-1.49×10-3 mm2/s) were significantly correlated with erythrocyte sedimentation rate, C-reactive protein, and white blood cell level (P < 0.001). (6) These findings indicate that diffusion-weighted imaging is a simple and stable method for detecting spinal tuberculosis and Brucella spondylitis. The diffusion-weighted imaging-apparent diffusion coefficient at a diffusion sensitivity coefficient of 400 s/mm2 has the greatest diagnostic efficacy in differentiating spinal tuberculosis from Brucella spondylitis, and the apparent diffusion coefficients of the affected vertebral bodies at different diffusion sensitivity coefficients are closely related to inflammatory status.

1. Introduction

Spinal tuberculosis, a non-suppurative granulomatous spinal infection, is prevalent worldwide and primarily caused by Mycobacterium tuberculosis. It often affects individuals with poor habits and low immunity. In contrast, Brucellar spondylitis results from Brucella infection transmitted from animals to humans. Both conditions can lead to spinal cord compression due to vertebral destruction or paravertebral abscess, causing lower limb numbness and muscle weakness, which complicates differential diagnosis.

In recent years, diffusion-weighted imaging (DWI) has played a significant role in diagnosing spinal infectious diseases. DWI can detect early signal abnormalities in bone and surrounding soft tissues and accurately assess the extent, severity, and stability of lesions. The apparent diffusion coefficient (ADC) derived from DWI reflects the diffusion speed and range of water molecules in tissues, which is restricted in structures with cell membranes. Different b-values in DWI can reflect the diffusion characteristics of water molecules, thereby indirectly indicating microstructural changes. Selecting an appropriate b-value is crucial for the accurate diagnosis of spinal tuberculosis and Brucellar spondylitis.