Figure 2 Schematic view of splenic-triggering multi-detector row computed tomography (MDCT) scanning protocol. For the multiphase MDCT protocol, patients with different levels of body mass index (BMI) received 352 or 440 or 550 mg I/kg of contrast medium. The injection duration was fixed at 25 s (Group A) or 30 s (Groups B and C), using the same flow rate to inject the contrast medium, followed by 30 ml of saline. The late hepatic arterial phase (HAP) scan was started 15 safter the trigger threshold (set at an increase of 50 HU) was reached in an ROI drawn within the splenic parenchyma at the level of the splenic artery. The portal venous phase (PVP) and delay phase (DP) image scanning started automatically 70 sand 180 safter the injection of contrast medium. HU – Hounsfield units; ROI – region of interest.