Application of whole-body diffusion-weighted MRI (WB-DWI) in diagnosis of bone metastases from lung cancer

Objective: In view of the characteristics of Whole-Body Diffusion-Weighted MRI (WB-DWI) and the difficulties in the diagnosis of bone metastases from lung cancer, our study aimed to explore the possible application of WB-DWI in diagnosis of bone metastases from lung cancer. Methods: 70 patients with lung cancer were selected in our hospital from August 2012 to June 2014. All the patients were subjected to both WB-DWI and bone scintigraphy within one week after admission. Images obtained using those two methods were analysed by two physicians using a double-blind method. Sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV) and accuracy rate of the two methods were compared. Results: 210 lesions and 83 affected areas were detected by WB-DWI, while 179 lesions and 83 affected areas were detected by bone scintigraphy. Sensitivity, specificity, PPV, NPV and accuracy rate of WBDWI were 90.7%, 96.30%, 97.5%, 86.67% and 92.86%, respectively, and values for bone scintigraphy were 86.05%, 88.89%, 92.5%, 80% and 87.14%, respectively. Those two methods showed similar sensitivity, PPV and NPV. Specificity of WB-DWI was slighter higher than that of bone scintigraphy, but the difference was not statistically significant (McNemar test, p=1). WB-DWI showed significantly better result in ROC curve analysis than that of bone scintigraphy. Conclusion: WB-DWI showed good agreement with bone scintigraphy in diagnosis of bone metastases from lung cancer. WB-DWI avoids the application of radiation, and also showed better result in ROC curve analysis compared bone scintigraphy. So WB-DWI is worth to be popularized in clinical study.