The utility of DW-MRI in the diagnosis of pancreatic focal lesions

Abstract

Background: Early diagnosis is crucial in management of pancreatic malignancy. DWMRI could be used in differentiating pancreatic lesions and judge about tumor aggressiveness. Patients & methods: Fifty patients were included in this prospective study with mean age ±43 years. Histopathology & follow up clinical results revealed 34 malignant and 16 benign lesions. All patients underwent non-contrast MRI examination and DWI at different b-values with ADC value measurements. Results: Conventional MRI poorly diagnosed pancreatic focal lesions with 79% Sensitivity, 68% specificity & 76% accuracy. In DWI with high b-value of 1000, 31/34 malignant lesions showed restricted diffusion with low ADC value (≤1.5 × 10−3 mm2/s) while 14/16 benign lesions showed mixed diffusion with higher ADC values (≥1.7 × 10−3 mm2/s). DWI at high b-value of 1000 with chosen ADC value of 1.5 as a cut-off value revealed high sensitivity (91.18%), 87.5% specificity, 93.84% PPV, 82.35% NPV and 90% accuracy in differentiating benign from malignant pancreatic lesions. Conclusion: DWMRI found to be a simple and non-invasive tool that aid in the diagnosis of pancreatic pathology with recommended high b-value and a cut-off ADC value of 1.5 that approved the highest sensitivity & specificity in differentiating benign from malignant pancreatic focal lesions. Keywords: DW-MRI pancreas, Pancreatic focal lesions