Discrimination between benign and malignant in vertebral marrow lesions with diffusion weighted MRI and chemical shift

摘要

Background Although the spine is the most common site of bone metastasis and the third most common site for metastatic disease following the lung and the liver, benign vertebral fracture due to osteopenia occurs in one third of cancer patients making it essential to determine whether the cause of vertebral collapse is benign or malignant. Objective To detect and differentiate benign from malignant vertebral marrow lesions with the use of Diffusion weighted MRI and chemical shift in order to optimize the protocol needed for the accurate diagnosis. Materials and methods In our study, we interpreted and analyzed the imaging data of 30 patients with suspected vertebral marrow lesion. They performed the routine MRI sequences of the spine (T1 , T 2, STIR, T 1 fat sat post-contrast enhancement) as well as the two non-routine sequences (DWI & in/opposed phase). We used the biopsy results or results of clinical and radiologic follow-up for at least 6 months, as the gold standard to classify the vertebral marrow infiltrative lesions as benign or malignant. Results Statistical analysis of the collected results was performed using DWI with its quantitative best cutoff ADC value being 0.67 × 10 ?3 mm 2 /s and chemical shift imaging with its quantitative best cutoff SIR being 0.94 showed their diagnostic value in discrimination between benign and malignant lesions with overall 94% sensitivity, 79% specificity, 87% accuracy for ADC value and 94% sensitivity, 71% specificity, 83% accuracy for SIR. Conclusion The addition of the two evolving MRI sequences (DWI and CSI) to the routine MRI protocol of cancer patients who examine the spine as part of their metastatic work-up promises to be an effective implement for characterization of vertebral marrow lesions being benign versus malignant.