Objective: To contrastive analyze the population characteristics and individual variations of enhancement modes of normal pancreas and aorta at intravenous injection rates of 3 mL/s and 2 mL/s.
Methods: Sixty-seven patients with normal pancreas were selected, and were divided randomly into 2 groups with different intravenous injection rates (3 mL/s for 35 patients in Group A and 2 mL/s for 32 patients in Group B). Single-level serial dynamic CT scan was performed at the level where the pancreas was best demonstrated. The enhancement values of pancreas and aorta for each time point of each patient were calculated, and the time-density curves of enhancement of pancreas and aorta of each patient were obtained. The peak enhancement and the time to reach the peak enhancement of pancreas and aorta of each individual patient were evaluated, and the 2 groups were compared. The individual variations of the enhancement modes of pancreas and aorta in each group were analyzed.
Results: The peak enhancement of pancreas was (75.7+/-17.0) Hu at (43.9+/-6.6) s for Group A, and (66.5+/-16.0) Hu at (55.2+/-5.0) s for Group B; the peak enhancement of aorta was (226.2+/-35.2) Hu at (35.4+/-4.5) s for Group A, (182.8+/-32.8) Hu at (48.0+/-3.7) s for Group B. There were significant differences in both the peak enhancement and the time to reach the peak enhancement of pancreas and aorta between the 2 groups. The coefficients of variation of time to reach the peak enhancement for pancreas and aorta were 15.0% and 12.7% in Group A, and 9.2% and 7.7% in Group B, respectively. The temporal windows of the optimal enhancement of pancreas were (9.7+/-4.5)s and (13.7+/-3.6)s in Group A and B, respectively.
Conclusion: Better enhancement of pancreas and aorta is obtained at 3 mL/s than 2 mL/s, the time to reach the peak enhancement of pancreas and aorta is comparatively earlier at 3 mL/s than 2 mL/s, and the temporal windows of optimal enhancement of pancreas and aorta are comparatively shorter at 3 mL/s than 2 mL/s.