Study Of Multisection Helical CT Perfusion Imaging For Pancreatic Diseases And Angiogenesis In Pancreatic Neoplasm

The differential diagnosis of pancreatic tumor is difficult. The conventional imaging techniques is not easy to identify the tumor in the pancreas because its finding bases just on morphological changes. With new theory and technique, CT perfusion imaging, which is regarded as a functional examination, is able to display the blood perfusion changes which can indicate the changes of intratumoral microvessel density (MVD) and capillary permeability indirectly. Integrating the morphological finding and CT perfusion imaging of pancreas, it is likely to increase the veracity of diagnosis. We try to perform the pancreatic CT perfusion imaging on patients with non-pancreatic and pancreatic disease to explore the characteristic of normal and abnormal pancreas. The clinical significance of this new technique is highly prospected.Part I Multisection Helical CT Perfusion Imaging for NormalPancreasObjective: Explore the characteristic of normal pancreatic CT perfusion imaging to find out the normal value, which is the baseline for following study. Methods: 39 cases without pancreatic diseases were examined for pancreatic perfusion from January 2003 to Feburery 2005. The multisection dynamic CT perfusion series was performed for pancreatic perfusion with cine mode (0.5s per rotation) on a multisection CT scanner (Lightspeed 16, GE, USA), 120kV, 60mA/80mA, 4×5 collimation. Contrast injection was done by using 50ml nonionic contrast agent (300mgI/ml), at a flow rate of 4ml/s with a power injector, and 6 seconds delay, and data acquisition lasted for 50 seconds. These data were processed on a GE AW4.0 workstation using perfusion 2 software package with deconvoiution method, and the mean BF, BV, MTT and PS were measured and statistically analyzed in normal pancreas.Results: The characteristic of normal pancreatic CT perfusion imaging: The whole pancreas is displayed as an organ with symmetrical blood flow (BF), blood volume(BV), mean transit time (MTT) and permeability surface area product (PS). The normal value of BF is measured as 9684.05± 1701.43 ml ■mhv'-kg"1, BV is 1362.26±827.10 ml-kg"1. MTT is 3.72±3.06 Sec. PS is 829. 80±278.99 ml-min^kg"1. Conclusion: Pancreatic CT perfusion imaging is a technique of functional imaging, which could display the blood perfusion changes of pancreas and indicate the changes of intratumoral MVD and capillary permeability indirectly. The normal pancreas is displayed as an organ with symmetrical blood flow (BF), blood volume (BV), mean transit time(MTT) and permeability surface area product (PS).Part II M ultisection Helical CT Perfusion Imaging for PancreaticDiseasesObjective: Explore the characteristic of CT perfusion imaging of various pancreatic disease. Comparing with normal value, evaluate the clinical significance of pancreatic CT perfusion imaging in diagnosing pancreatic tumors. Methods: 53 cases with different pancreatic diseases were examined for pancreatic perfusion from January 2003 to Feburery 2005. These data were processed on a GE AW4.0 workstation using perfusion 2 software package with deconvolution method, and the mean BF, BV, MTT and PS were measured and statistically analyzed in 24 pancreatic adenocarcinoma, 8 duodenal or ampullary carcinoma, 6 acute edematous pancreatitis. And the mean BF, BV, MTT and PS were also measured in 3 pancreatic solid-pseudopapillary neoplasm, 3 metastasis in the pancreatic head from gallbladder carcinoma, 3 pancreatic cystadenoma, 5 pancreatic cysts.Results: BF, BV, PS and PS/BF of pancreatic adenocarcinoma, BF, BV and PS of ampullar adenocarcinoma, BV of acute edema pancreatitis (AEP) has statistical difference with that of normal pancreas. But MTT has no statistical difference. Also, BF, BV, PS and MTT is compared between pancreatic and ampullar adenocarcinoma, showing there is no statistical difference, but PS/BF has statistical difference. BF, BV and PS is lower in pancreatic solid-pseudopapillary neoplasm, metastasis in the pancreatic head from gallbladder carcinoma and pancreatic cystadenoma; and MTT is longer in metastasis in the pancreatic head from gallbladder carcinoma and pancreatic cystadenoma. BF, BV, PS and MTT of pancreatic cysts is 0. Conclusion: The characteristic of pancreatic adenocarcinoma in CT perfusion imaging is significant decrease of blood flow (BF), blood volume (BV), permeability surface area product (PS) and increase of PS/BF. The ampullar...