Study Of Scanning Parameters On Pancreas CT Enhancement

Objective To assess the effects of different scanning parameters on pancreatic enhancement CT and to find an appropriate protocols for examining the pancreas. Materials and Methods 1. Twenty patients were injected by 1.5 ml / kg of contrast material (Omnipaque 300 mg I/mi) and the injection rate was 3m1/s. Scans were obtained in arterial phase, pancreatic phase and portal venous phase, delay 15-1 8s, 40s and 70s ,respectiveiy. Mean CT enhancement values of pancreas were measured for three phases. 2. Fifty patients were randomly divided into five groups with different injection rates and doses. Group I (1.5 mi/kg, 3 mi/s ) , Groupll(1.Smi/kg, 2.5 mi/s), Group 111 (1 mi/kg, 3 mi/s) ,Group N (1 mi/kg, 2.5 mi/s ) and Group V (fixed dose 75m1, 2.5 ml!s) , each group has ten cases. Scans were obtained in pancreatic phase and portal venous phase, delay 40s, 70s. Mean CT enhancement values of pancreas were obtained for five groups. Results In the pre-test , mean pancreatic enhancement value was significantly greater in the pancreatic phase (69.8 13.13 Hu) than both in arterial phase (24.72 11 .86Hu )(p<0.05) and portal venous phase (52.28 l0.55Hu )(p<0.05). Mean CT enhancement values of pancreas in pancreatic phase was 71.05 9.64 Hu in Group I, 64.04 9.61 Hu in Groupll, 45.16.98 Hu in Group III , 44.1611.27 Hu in Group N and 50.20 13.59 Hu in Group V .There were significant differences in mean pancreatic enhancement value between Group I and Group III (p<0.05) , between Group II and Group N (p<0.05) ,and between Group II and Group V (p<0.05). There was not significant differences between Group I and Group II ,between Group Ill and Group N, and between Group N and Group V. Conclusion Pancreatic enhancement value was significantly greater in the pancreatic phase than both in arterial phase and in portal venous phase , higher dose increased the pancreatic enhancement value 1 .Smi/kg of contrast material, 2.5-3m1/s is an appropriate scanning parameter.