Application Study Of MR Diffusion Weighted Imaging In Musculoskeletal Tumors

Objective:To investigate the applied value of3.0T magnetic resonance diffusion weighted imaging (MR-DWI) in the qualitative diagnosis of musculoskeletal benign and malignant tumors.Methods:60patients with musculoskeletal tumors pathologically confirmed by surgery or biopsy underwent conventional MRI and DWI (different b values of300,600and900s/mm2). Array spatial sensitivity the encoding technique (ASSET) and single-shot echo planar imaging (SS EPI) sequence were applied to DWI. The DWI signal intensity of benign and malignant musculoskeletal tumors with different b values was analyzed and the apparent diffusion coefficient (ADC) values of the lesions were measured. The difference of ADC values of musculoskeletal benign and malignant tumors was compared among different b values. Receiver operating characteristic curves (ROC) were analyzed.Results:①On DWI imaging, there was no significant differences of the signal intensity musculoskeletal benign and malignant tumors with different b values (X2=3.791,p>0.05).②There was significant differences of ADC values between musculoskeletal benign and malignant tumors with b value of300s/mm2,600s/mm2and900s/mm, respectively(p<0.05); There was significant difference in the ADCs of the same lesion between b=300s/mm2and b=600and900s/mm2but no difference between600s/mm2and900s/mm2.③The area under curve (AUC) values of ROC curve were0.910,0.916,0.944(b=300s/mm2,600s/mm2and900s/mm2, respectively), all with diagnostic significance. The AUC with b value of900s/mm2was the largest, and the high sensitivity (93.33%) and specificity (86.67%) were obtained when the optimal threshold of ADC value was1.26X10-3mm2/s in the differentiation of benign and malignant tumors.Conclusion:ADC values play an important role in differentiating musculoskeletal benign tumors from malignant lesions, b values have influence on ADC values. The optimal b value is900s/mm2.