The value of multidetector-row CT in the preoperative detection of pancreatic insulinomas

The authors sought to quantitatively analyse enhancement characteristics of pancreatic insulinomas in different phases and determine the value of multidetector-row computed tomography (CT) for detecting insulinomas. Forty-six patients with surgically proven insulinomas diagnosed between 2002 and 2007 were retrospectively reviewed. These patients underwent single-phase (group 1) or dual-phase (group 2) helical CT scanning. Sensitivity for detecting insulinomas in group 2 was superior to that in group 1 (p < 0.05).The sensitivity for insulinoma detection in the arterial phase was superior to that in the portal-venous phase (p < 0.05). The mean attenuation values of the insulinomas and normal pancreas during the unenhanced arterial and portal-venous phases were, respectively, 40.5 +/- 8.75 HU (Hounsfield units), 114.48 +/- 27.30 HU, 112.19 +/- 19.52 HU and 44.56 +/- 6.48 HU, 81.16 +/- 15.22 HU, 90.54 +/- 13.80 HU, and there was statistical difference between them (p=0.000). The contrast enhancement of insulinomas in the arterial and portal-venous phases was 74.03 +/- 29.51 HU and 70.90 +/- 21.93 HU, respectively, and there was no statistical difference between them (p=0.499). The tumour to normal-pancreas attenuation differences in the arterial and portal-venous phases were respectively 33.32 +/- 20.96 HU and 20.58 +/- 16.32 HU, respectively, and there was statistical difference between them (p=0.011). Dual-phase CT has a promising sensitivity in detecting pancreatic insulinomas. The acquisition of images in the arterial phase is more helpful for detecting insulinomas.