the application of apparent diffusion coefficient and chemical shift images in differentiation of benign and malignant vertebral lesions

Background: one of the most common clinical problems is the differentiation of vertebral marrow lesions, particularly in the elderly patients. since clinical staging, treatment strategy, and prognosis in malignant and benign lesions are different, it is very essential to determine the benign and malignant nature of vertebral pathologies. objectives: the aim of this study was to assess the value of diffusion weighted magnetic resonance imaging and chemical shift in the diagnosis, characterization, and differentiation of benign and malignant vertebral bone marrow lesions and to define the sensitivity and the specificity in differentiating benign and malignant vertebral lesions according to the optimal cut-off apparentdiffusion- coefficient (adc) values and signal intensity ratio (sir). methods: this study included 39 patients with 86 untreated vertebral lesions that underwent the routine mri sequences of the spine as well as the two non-routine sequences (dwi and in/opposed phase). the optimal cut-off adc value and sir were determined for the differentiation of benign and malignant lesions. we used the biopsy results and clinical follow-up, as the gold standard to classify the vertebral marrow lesions as benign and malignant. results: of the examined 39 patients, 67 focal lesions were included that 42 lesions proved to be malignant and 25 lesions diagnosed as benign. the results of this study showed that the adc values of benign lesions were significantly (p < 0.001) higher than untreated metastatic lesions. sir values were calculated 1.155 ± 0.183 in malignant lesions, while it was 0.649 ±0.341 in benign lesions. threshold analysis yield optimal cut-off point that showed adc min and adc mean and sir had high sensitivity, specificity, and accuracy in the discrimination of benign and malignant lesions. conclusions: quantitative diffusion weighted and chemical shift mr imaging are effective non-invasive technique in differentiating benign from malignant vertebral bone marrow lesions that provide additional information to the routine mri sequences.