ABSTRACT
Objective To investigate the feasibility of pancreatic DWI at a 3T MR imager and its value for the qualitative diagnosis of pancreatic tumors. Methods For 20 normal healthy volunteers and 47 patients with pancreatic tumors [21 pancreatic carcinoma (PC), 7 mass-forming chronic pancreatitis (MFCP)and 19 cystic lesions), routine pancreatic MRI and pancreatic DWI using b values (500 and 1000 mm2/s)were obtained, the DWI signal intensity (SI) and apparent diffusion coefficient (ADC) value of pancreatic lesions and adjacent tissue was measured. Results In the b = 500 and 1000 mm2/s DWI images, there was no significant difference in ADC value between different parts of normal pancreas. But PC and MFCP were shown as hyperintensity mass, in addition, the related SI1000 of PC at b = 1000 mm2/s DWI was significantly higher than that of MFCP (1.238 +0.448 vs. 0.371 +0.293, P＜0. 01). Compared with normal pancreas,beth PC and MFCP presented as decreased ADC500 and ADC1000 value. The ADC1000 of PC was significantly lower than that of MFCP [ ( 1. 087 + 0. 175 ) mm2/s vs. ( 1. 279 ± 0.213 ) mm2/s]. Pancreatic cystic lesions were shown as hyperintensity in DWI at b = 500 mm2/s, but were depicted as iso-intense signal or low-signal lesions in DWI using b = 1000 mm2/s. Both ADC500 and ADC1000 of pancreatic cystic lesions were higher than that of normal pancreas. Conclusions 3T-MR DWI is helpful to differentiate pancreatic lesions. High b value DWI is more valuable for the qualitative diagnosis of pancreatic mass.