Diagnostic Significance of Diffusion-Weighted MRI in Renal Cancer.

BACKGROUND: This study aimed to investigate whether diffusion-weighted imaging (DWI) could contribute to the discrimination between benign and malignant renal cancer. METHODS: We searched the PubMed electronic database for eligible studies. STATA 12.0 software was used for statistical analysis. The SMD and 95% CI were calculated. RESULTS: Decreased ADC signal was seen in all renal cancer patients (cancer tissue versus normal tissue: SMD = 1.63 and 95% CI = 0.96~2.29, P < 0.001; cancer tissue versus benign tissue: SMD = 2.22 and 95% CI = 1.53~2.90 and P < 0.001, resp.). MRI machine type-stratified analysis showed that decreased ADC signal was found by all included MRI machine types in cancer tissues compared with benign cancer tissues (all P < 0.05). The ADC values of renal cancer patients were significantly lower than those of normal controls for all included P values (all P < 0.05), and there was a decreased ADC signal at b-500, b-600, b-1000, b-500, and 1000 gradients compared with benign cancer tissues (all P < 0.05). CONCLUSION: Our study concluded that decreased ADC signal presented in DWI may be essential for the differential diagnosis of renal cancer.