The Application Of MR Diffusion-weighted Imaging In The Differentiation Of Benign And Pathologic Vertebral Fractures

Objective: To investigate the value in distinguishing benign and pathologic vertebral compression fractures with MR diffusion - weighted imaging(DWI). Methods: 63 patients with 105 vertebral fractures were underwent routine MRI scanning and echo–planar DWI(EPI/DWI).The materials were divided into benign group(n=44,25 cases),pathologic group (n=61,38cases),and normal vertebral body group (n=61,61).The image quality with different b values was analyzed and compared,quantitatively by signal-to-noise ratio (SNR).Signal intensities on DWI were compared and apparent diffusion coefficient (ADC) values of normal and abnormal vertebral bodies were calculated. ADC values among the three abnormal vertebral group were quantitatively analyzed and compared.Results:The ADC values of benign, malignant, and normal vertebral bodies were (2.40±0.75)×10^-3 mm²/s, (1.52±0.47)×10^-3 mm²/s, and (0.97±0.29)×10^-3 mm²/s,respectively. The smaller the b value was,the better the DWI image quality would be. Mean SNR of images obtained with b value 0,100,300,500,and 700s/mm² were 22.20±3.3,24.8±3.5,18.9±2.8,9.0±2.7å’Œ5.9±1.6,respectively.The difference among them was statistically significant.The ADC values of the tow abnormal groups were higher than normal group (P<0.01),and benign group higher than pathologic one (P<0.01).Conclusion:(1)A b value about 300 s/ mm² is recommended when diffusion-weighted MRI scanning is used to differentiate benign from pathologic vertebral compression fractures.(2)MR quantitative ADC measurement is helpful to a certain degree in differentiating the causes of vertebral fractures.(3)Qualitative diffusion weighted MR imaging can not accurately distinguish pathologic with benign vertebral compression fractures.