Differentiation of chronic focal pancreatitis from pancreatic carcinoma by in vivo proton magnetic resonance spectroscopy

Objective: To determine the differences between the in vivo proton magnetic resonance spectroscopy (H-1-MRS) features of chronic focal pancreatitis and pancreatic carcinoma and to evaluate the possibility of discriminating chronic focal pancreatitis from pancreatic carcinoma by analysis of in vivo H-1-MR spectra. Methods: The H-1-MR spectra from 36 human pancreases were evaluated in vivo. This series included 15 cases of chronic focal pancreatitis and 21 cases of pancreatic carcinoma. All cases were confirmed histopathologically after surgical resection. The ratios of the peak area (P) of all peaks at 1.6-4.1 ppm to lipid (0.9-1.6 ppm) (P [1.6-4.1 ppm]/P [0.9-1.6 ppm]) in the chronic focal pancreatitis and pancreatic carcinoma groups were evaluated, and the results were compared. The sensitivity and specificity of the analysis were also evaluated by in vivo H-1-MR spectra for discriminating between chronic focal pancreatitis and pancreatic carcinoma. Results: In vivo 'H-MR spectra showed significantly less lipid in chronic focal pancreatitis than in pancreatic carcinoma. The ratio of P (1.6-4.1 ppm)/P (0.9-1.6 ppm) in chronic focal pancreatitis was significantly higher than that in pancreatic carcinoma (P < 0.05) because of a decreased peak area of lipids. The means +/- SDs of P (1.6-4.1 ppm)/P (0.9-1.6 ppm) in the chronic focal pancreatitis and pancreatic carcinoma groups were 2.78 +/- 1.67 and 0.51 +/- 0.49, respectively. Using a value of < 2.5 as positive for pancreatic cancer, the sensitivity and the specificity for pancreatic cancer were 100% and 53.3%, respectively. Conclusion: Chronic focal pancreatitis and pancreatic carcinoma can be distinguished from each other by analysis of in vivo 'H-MR spectra, and in vivo H-1-MRS can be a useful method for making a differential diagnosis between chronic focal pancreatitis and pancreatic carcinoma.