Dynamic study of the Pancreas with Spiral CT: Comparison of Amount of The Contrast Medium

Nam, Kyung Jin; Ahn, Seung Eon; Yoon, Seong Kuk; Kim, Jae Ik; Choi, Jong Cheol; Lee, Young Il

Abstract

PURPOSE: To determine the hemodynamics of the pancreas by investigating the enhancement patterns of pancreaticparenchyma, as seen on spiral CT, after the administration of various amounts of contrast medium, and to determineoptimal scan time by knowing the peak time of normal pancreatic parenchyma.
MATERIALS AND METHODS
Between January1995 and April 1997 55 cases of normal abdominal CT with dynamic enhancement study on pancreas, the subject were38 cases(28 persons) with good image, aged 21-65 years, men were twenty-one and women were seven. Non-ioniccontrast medium, 30ml(n=15), 60ml(n=9), 990ml(n=7), and 120ml(n=7) were injected at a rate of 3ml/sec. From 20sec. after the start of injection, 15 images were obtained at 3-sec intervals. Before and after injection, R.O.I.was applied to each image, and for the aorta and pancreatic parenchyma, Hounsfield units(H.U.) were measured; timeof enhancement and maximal H.U. were also measured.
RESULTS
After 30, 60, 90, and 120ml of contrast mediuminjection, mean maximal H.U. of pancreatic parenchyma was 36+/-7, 54+/-6, 68V13, and 92+/-8, respectively; mean valueat peak parenchymal enhancement of the pancreas was 27+/-3, 32+/-3, 42+/-3, and 52+/-3, respectively. Time intervalsof maximal enhancement of aorta and pancreatic parenchyma could not be obtained in 30ml injection, but 5,4+/-2.5,4.2+/-1.6, and 6.0+/-2.1sec in 60, 90, and 120ml injection, respectively.
CONCLUSION
Maximal H.U. of parenchymalenhancement of the pancreas is directly proportional to the amount of injected contrast medium and the peak timeof parenchymal enhancement was 12sec after the injection of contrast material. Time interval of maximalenhancement of aorta and pancreatic parenchyma was 5.2+/-2.1sec.