Can diffusion-weighted MRI replace conventional contrast enhanced MRI in the differentiation between benign and malignant pancreatic masses?

Purpose: To evaluate the role of diffusion weighted MRI (DW MRI) in the differentiating between benign and malignant pancreatic masses Patients and Methods: Sixty patients (36 men, mean age, 62 years; range, 48-72 years], 24 women (mean age, 64 years; range, 54-69 years] suspected to have solid pancreatic masses were examined by conventional and DWI. None of our patients had a history of pancreatic disease. DWI of the pancreas was performed in addition to the routine liver MR. Final diagnosis was obtained by diagnostic biopsy, lab. data and follow up. Results: 38 patients had a benign lesion and 22 patients had a malignant lesion. Using DWI, 36 cases were diagnosed to have benign lesions and 24 cases were diagnosed to have malignant lesions. There were two false positive cases due to low ADC value. The mean ADC values of malignant lesions were lower compared with benign lesion. The mean ADC value for malignant lesions was 1.1 +/- 0.201 multiplication sign 10^-3 mm²/sec, and for benign lesions it was 1.6 + l - 0.121 multiplication sign 10^-3 mm²/sec. Conclusion: DWI and ADC values can help differentiate between benign and malignant pancreatic masses. Also DWI can be used for investigating patients for whom contrast-enhanced CT or MRI studies are contraindicate