[The value of dual-source dual-energy CT with iodine overlay in the diagnosis of acute necrotizing pancreatitis].

Objective: To investigate the clinical value of dual-source computed tomography dual-energy Iodine overlay technique in the imaging diagnosis of acute necrotizing pancreatitis.
Methods: The imaging data were retrospectively analyzed in 67 cases of acute necrotizing pancreatitis underwent contrast-enhanced dual-source dual-energy CT in portal venous phase. The CT imaging parameters, including the difference of CT value between pancreatic parenchyma and necrotic lesion, contrast-to-noise ratio of pancreatic parenchyma-to-necrosis, area of pancreatic necrosis and score of subjective diagnosis, were measured and assessed on CT images of 80 kV, 140 kV, weighted-average 120 kV as well as Iodine overlay.
Results: The differences of CT value between pancreatic parenchyma and necrosis in the images of 80 kV, 140 kV, weighted-average 120 kV and Iodine overlay were (67.40 +/- 20.82) HU, (42.87 +/- 14.99) HU, (48.69 +/- 15.82) HU, (33.01 +/- 10.26) HU, respectively; contrast-to-noise ratios of pancreatic parenchyma-to-necrosis of each group were 8.36 +/- 3.58, 5.85 +/- 2.65, 7.68 +/- 3.51, 10.60 4.34; area of pancreatic necrosis of each group was (3.78 +/- 2.68) cm2, (3.28 +/- 2.59) cm2, (3.37 +/- 2.46) cm2, (2.42 +/- 1.98) cm2; the score of subjective diagnosis of each group was 3.88 +/- 0.33, 3.31 +/- 0.80, 3.58 +/- 0.66, 2.81 +/- 0.76, respectively. The four indexes in the images of Iodine overlay were significantly different from those of another three groups (P < 0.05). Contrast-to-noise ratio of pancreatic parenchyma-to-necrosis in the images of Iodine overlay was significantly higher than that of another three groups, while the difference of CT value, area of pancreatic necrosis and score of subjective diagnosis were lower. CONCLUSION; Dual-source CT dual-energy Iodine overlay is not helpful to improve subjective judgment in the diagnosis of pancreatic necrosis, but contributes to the display of hypoperfusion area around the necrosis.