Characterization of focal pancreatic lesions using normalized apparent diffusion coefficient at 1.5-Tesla: Preliminary experience

AbstractPurposeTo compare the capabilities of apparent diffusion coefficient (ADC) and normalized ADC using the pancreatic parenchyma as reference organ in the characterization of focal pancreatic lesions.Patients and methodsThirty-six patients with focal pancreatic lesions (malignant, n=18; benign tumors, n=10; focal pancreatitis, n=8) underwent diffusion-weighted MR imaging (DWI) at 1.5-Tesla using 3 b values (b=0, 400, 800s/mm2). Lesion ADC and normalized lesion ADC (defined as the ratio of lesion ADC to apparently normal adjacent pancreas) were compared between lesion types using nonparametric tests.ResultsSignificant differences in ADC values were found between malignant (1.150×10−3mm2/s) and benign tumors (2.493×10−3mm2/s) (P=0.004) and between benign tumors and mass-forming pancreatitis (1.160×10−3mm2/s) (P=0.0005) but not between malignant tumors and mass-forming pancreatitis (P=0.1092). Using normalized ADC, significant differences were found between malignant tumors (0.933×10−3mm2/s), benign tumors (1.807×10−3mm2/s) and mass-forming pancreatitis (0.839×10−3mm2/s) (P