Characterization of Pancreatic Tumors with Quantitative Perfusion Analysis in Contrast-Enhanced Harmonic Endoscopic Ultrasonography

Objectives: This study evaluated whether quantitative perfusion analysis with contrast-enhanced harmonic (CH) endoscopic ultrasonography (EUS) characterizes pancreatic tumors, and compared the hemodynamic parameters used to diagnose pancreatic carcinoma. Methods: CH-EUS data from pancreatic tumors of 76 patients were retrospectively analyzed. Time-intensity curves (TIC) were generated to depict changes in signal intensity over time, and 6 parameters were assessed: baseline intensity, peak intensity, time to peak, intensity gain, intensity at 60 s (I 60 ), and reduction rate. These parameters were compared between pancreatic carcinomas (n = 41), inflammatory pseudotumors (n = 14), pancreatic neuroendocrine tumors (n = 14), and other tumors (n = 7). All 6 TIC parameters and subjective analysis for diagnosing pancreatic carcinoma were compared. Results: Values of peak intensity and I 60 were significantly lower and time to peak was significantly longer in the groups with pancreatic carcinomas than in the other 3 tumor groups (p < 0.05). Reduction rate was significantly higher in pancreatic carcinomas than in pancreatic neuroendocrine tumors (p < 0.05). Areas under the receiver-operating characteristic curves for the diagnosis of pancreatic carcinoma using subjective analysis, baseline intensity, peak intensity, intensity gain, I 60 , time to peak, and reduction rate, were 0.817, 0.664, 0.810, 0.751, 0.845, 0.777, and 0.725, respectively. I 60 was the most accurate parameter for differentiating pancreatic carcinomas from the other groups, giving values of sensitivity/specificity of 92.7/68.6% when optimal cutoffs were chosen. Conclusions: In pancreatic carcinomas, TIC patterns were markedly different from the other tumor types, with I 60 being the most accurate diagnostic parameter. Quantitative perfusion analysis is useful for differentiating pancreatic carcinomas from other pancreatic tumors.