The CT Angiography Of The Pancreatic Artery With 64-detector Spiral CT

Part one. Correlation between enhanced CT value of abdominal aortaand the visualization ratios of pancreatic arteriesObject: To investigate the correlation between artery phase CT value of abdominal aorta using 64-Detector Spiral CT with the visualization ratios of pancreatic arteries.Materials and Methods: 152 cases who underwent abdominal artery phase scanning were enrolled. All cases were divided into 3 groups according to the different enhanced CT value of abdominal aorta, A group:250~349Hu, B group:350~449Hu, C group:≥450Hu. One observer used volume rendering(VR), maximum intensity projection(MIP) and multi-planar reconstruction(MPR) to evaluate the visualization ratio of the ASPDA、PSPDA、AIPDA、PIPDA、DPA、TPA、PMA、CPA, and Used ROC curve to analysis the correlation with the visualization of pancreatic arteries.Results: ①. The total visualization ratios of pancreatic arteries in group A、B、C are 67.0%、83.7%、88.7% respectively, group B and C are higher than A, which have significant differences(P <0.05), group B and C have no significant differences(P >0.05). ②. The visualization ratios of each pancreatic artery in group A、B、C are ASPDA(98.3%、100%、100%)、PSDPA(93.1%、94.2%、95.1%)、AIPDA(64.0%、84.2%、93.0%)、PIPDA(59.0%、88.6%、98.3%)、DPA(72.1%、92.0%、95.5%)、TPA(65.6%、89.8%、90.0%)、PMA(62.3%、83.7%、88.2%)、CPA(21.6%、39.4%、50.9%) respectively, ASPDA、PSDPA of 3 groups have no significant differences(P >0.05), AIPDA、PIPDA、DPA、TPA、PMA、CPA of group B and C are higher than A, which have significant differences(P <0.05), group B and C have no significant differences(P >0.05). ③.According to ROC curve, the visualization of AIPDA、PIPDA、DPA 、TPA、PMA、CPA are associated with CT value of abdominal aorta,which has significant differences(P <0.05), the best cutoff point of each artery is 340.5Hu、377.0Hu、335.0Hu、353.0Hu、348.5Hu、342.5Hu respectively, the median of the 6 best cutoff point is 345.5Hu. ④.According to the enhanced CT value of abdominal aorta, merged group B and C into group ≥350Hu, group A is group <350Hu.The visualization ratios of each pancreatic artery in group <350Hu and ≥350Hu are ASPDA(98.3%、100%)、PSDPA(93.1%、94.5%)、AIPDA(64.0%、87.9%)、PIPDA(59.0%、92.3%)、DPA(72.1%、93.4%)、TPA(65.6%、90.1%)、PMA(62.3%、85.7%)、CPA(21.6%、44.0%) respectively, ASPDA、PSDPA of 2 groups have no significant differences(P >0.05), AIPDA、PIPDA、DPA、TPA、PMA、CPA of group ≥350Hu are higher than group <350Hu, which have significant differences(P <0.05).Conclusion: Pancreatic artery could have a higher visualization ratio,while enhanced CT value of abdominal aorta is ≥ 350 Hu.Part Two. The self-control study of dilating pancreatic artery bynitroglycerinObject: To evaluate the visualization ratios and image quality of pancreatic arteries after holding nitroglycerin under the tongue with 64-Detector Spiral CT pancreatic artery angiography.Materials and Methods: According to designed inclusion and exclusion criteria, 36 cases were enrolled. According to the principle of self-control study, the case was divided into holding nitroglycerin group and control group. Holding nitroglycerin group:holding nitroglycerin 0.5mg under the tongue. One observer used VR、MIP、MPR to evaluate the visualization ratio of the ASPDA、PSPDA、AIPDA、PIPDA、DPA、TPA、PMA、CPA. Two blinded observers independently assessed image quality of pancreatic artery by using a four point scale(score 3~0). A score of 3 or 2 was defined as good image quality. One observer measure the diameter of initiation part of each pancreatic artery on MIP image.Results: ①. The total visualization ratios of pancreatic arteries in holding nitroglycerin group、control group are 69.4%、83.4% respectively, holding nitroglycerin group is higher than control group,which have significant differences(P <0.05). ②. The visualization ratios of each pancreatic artery are ASPDA(100%、97.0%)、PSDPA(94.4%、88.9%)、AIPDA(83.3%、66.7%)、PIPDA(80.6%、55.6%)、DPA(91.7%、80.6%)、TPA(77.8%、61.1%)、PMA(91.7%、69.4%)、CPA(50%、36.1%)respectively, ASPDA、PSDPA of 2 groups have no significant differences(P >0.05), AIPDA、PIPDA、DPA、TPA、PMA、CPA of holding nitroglycerin group are higher than control group, which have significant differences(P <0.05). ③.The “excellent” ratio of pancreatic arteries in holding nitroglycerin group is 71.8%(181/252), higher than 44.7%(97/217) in control group, which has significant differences(P<0.05). ④. The diameter of initiation part of ASPDA、PSPDA、AIPDA、PIPDA、DPA、TPA、PMA、CPA in holding nitroglycerin group are 1.9±0.5mm、1.8±0.4 mm、1.7±0.4 mm、1.6±0.4 mm、1.8±0.3 mm、1.8±0.5 mm、1.6±0.3 mm、1.5±0.2 mm respectively, higher than them in control group(1.4±0.4mm、1.3±0.3 mm、1.3±0.4 mm、1.2±0.2 mm、1.3±0.2 mm、1.3±0.2 mm、1.3±0.3 mm、1.2±0.3 mm), which has significant differences(P <0.05). ⑤.The enhanced CT value of abdominal aorta in holding nitroglycerin group 、 control group are 359.6±69.0Hu 、 320.2±41.5Hu respectively, holding nitroglycerin group is higher than control group,which has significant differences(P <0.05).Conclusion: Holding nitroglycerin under the tongue can increase the diameter of pancreatic artery and the enhanced CT value of abdominal, which can improve the image quality and visualization ratio of pancreatic artery.