OBJECTIVETo investigate the perfusion characteristics of normal pancreas and insulinoma on multi-slice spiral CT (MSCT).

METHODSTotally 21 subjects with suspected insulinoma were enrolled. Sixteen-slice spiral CT was used for perfusion scan following a standard contrast-enhanced scan. The surgical and pathological outcomes were collected for comparison. Perfusion characteristics, including blood flow (BF), patlak blood volume (pBV), time to peak (TTP), permeability, and peak enhancement (PE) of insulinomas and normal pancreas parenchyma were analyzed based on the MSCT data sets subsequently.

RESULTSBenign insulinoma was pathologically confirmed in 12 out of the 21 subjects, while the remaining 9 subjects were normal. Technical failures were experienced in 2 (9.5%) subjects. In both normal and tumor-suffered subjects (n = 19), perfusion parameters of normal pancreatic parachyma were measured as follows: BF (p) = 104. 9 +/- 28.9, pBV (p) = 166.4 +/- 41.8, TrP (p) = 133.3 +/- 24.4, Permeability (p) = 81.3 +/- 24.4, and peak enhancement (p) = 121.3 +/- 31.1. In subjects with insulinoma (n = 11), perfusion parameters of tumor tissue were measured as follows: F (i) = 206.5 +/- 42.2, BV (i) = 315.9 +/- 79.0, TFP (i) = 123.2 +/- 18.8, Permeability (i) = 102.5 +/- 54. 8, and peak enhancement (i) = 221.3 +/- 48.5. Results of F, BV, and peak enhancement in these two kinds of tissue showed significant differences (P < 0.01), while there were no significant difference (P > 0.05) in TTP and permeability between normal pancreatic parenchyma and insulinoma.

CONCLUSIONSBenign insulinoma has perfusion characteristics of increased blood flow and blood volume, but its TTP is consistent with normal pancreas and has normal permeability. MSCT allows further understanding of the blood flow of the normal pancreas and its benign tumor insulinoma.