Measurement of the apparent diffusion coefficient in intraductal mucin-producing tumor of the pancreas by diffusion-weighted echo-planar MR imaging

Background: We investigated whether diffusion-weighted echo-planar magnetic resonance (MR) imaging can help differentiate intraductal mucin-producing tumors of the pancreas from other cystic lesions. Methods: Diffusion-weighted echo-planar MR imaging was performed in patients with mucin-producing tumors (n = 19), pseudocysts (n = 9), chronic pancreatitis with diffuse main pancreatic dilatation (n = 5), and serous cystadenomas (n = 2). Images were obtained with diffusion sensitizing gradients of 30, 300, and 900 s/mm(2). The apparent diffusion coefficient (ADC) was calculated. Results: The mean (+/- standard deviation) ADCs of mucin-producing tumors (2.8 x 10(-3) mm(2)/s +/- 1.0 x 10(-3)), pseudocysts (2.9 x 10(-3) mm(2)/S +/- 1.2 x 10(-3)), dilated main pancreatic duct in chronic pancreatitis (3.3 x 10(-3) mm(2)/s +/- 1.2 x 10(-3)), serous cystadenomas (2.9 x 10(-3) and 2.6 x 10(-3) mm(2)/s), and cerebrospinal fluid (3.5 x 10(-3) mm(2)/s +/- 1.1 x 10(-3)) were not statistically different. Conclusion: It is difficult to differentiate between mucin-producing tumors and other cystic lesions by ADC measurements when using diffusion-weighted echo-planar MR imaging.