Probe Into Optimal Scan Delay Time And Premiliary Clinic Applicatioan In 64 Rows Spiral CT Portography

Compute Tomography Arterial Portography(CTAP)is used to adapt for display the Disease of portal,It is injury.Its advantage about 64-rows spiral computer tomography portography lies in:spatial and tempral definite can arrive in the optimum the same time,it also can scan large area in a breathhold condition,and we can improve the image quality of vessle reconstruct with sheet-slice and sheet-space,and also need less time and enhancement.Multi-rows spiral Computer Tomography Portography(MSCTP)has obvious advantages rather than transverse section imagine.It can display the antanomy and variation of the portal accurately, directly evaluated the location and outline.And it is unharmed,quick and economic in observing three-dimensional vessel imagine reconstruction by computer.Furthermore,64-rows spiral CT is able to accomplish hepatic multi-phase scan including MSCTA and MSCTP;and meantime,CTP can get the brief of hepatic parenchyma and find out the definite metastasis evidence of abdominal cavity in database using.But because of scan delay time's report of 64-rows spiral CT is less,writer preliminarily probe into the optimal scan delay time with different contrast medium density and its injection rate.PARTⅠ:Study the optimal delay time Of 64-rows spiral CT Portography with low dose experimental injection test.Objective:Probe into the optimal delay time with different injection rate and consistency of contrast media in 64-rows spiral CT portography by low dose experimental injection test,and compared the three outcome's difference when the consistency of main portal vein is highest.Materials and methods:1,45 healthy volunteers were choosed from Apr.2007 to Jun.2007,they were divided into three groups randomly with different injection rates of contrast medium:Group A(3mL/s),Group B(4mL/s)and Group C (5mL/s),each group is 15.All patients took clear water orally before scan and adopted position cephalopodially.Plain scanning was performed firstly with a GE Lightspeed Ultra 64,finding out the main portal injected by median cubital vein using power injector,each group prep time is 20s,the scanning was vein,then dynamic CT scanning at the level of here,As well as 15-20ml non-ion contrast medium(300mg/ml)was repeated every 1 second for 50 seconds with the scanning time of 1.0 second.Firstly using rigion of interest(ROI)at the main portal vein,we can acquire the enhancement peak time through the time-density curves;secondly we scan according to the acquisition and delay 3-5 seconds with injecting 70-80ml contrast medium,The scanning ranges from diaphraglnatic dome to the level of lumber three;thirdly we delivered all data to ADW4.3 workstation,while lamellar reconstruction,fourthly we compare the difference of acquisition CT values when the scan delay time is optimum.MIP and VR reconstruction were done,evaluate the imagine quality with different injection rate.Statistical analysis was used SPSS 11.5 soft package(one-way ANVOA)to determine whether a significant difference existed.2,based on above-mentioned research,90 healthy volunteers(including 30 examinee in partⅠ)from Jul.2007 to Nov.2007 were examined according to the same technical of scan,and reconstruction and statistical analysis is the same.90 volunteers were divided into three group(D,E,F)with different contrast medium consistency,at the same time,According to the different injection rate,every group were divided into group 1 and 2,Based on the date compare the difference of the delay time and imagine quality.Result:1,The optimal delay time of group A(3mL/s),group B(4mL/s)and group C(5mL/s)respectively is 42s,32s and 29s,The CT value of three group respectively is 202.09Hu,215.87Hu,243.16Hu,they had no difference each other.2,The peak enhancement time of group D1,E1,F1 respectively is 42s,43s,50s,the time of groupD2,E2,F2 respectively is 33s,34s,44s.3,When the scan time is optimum the average CT value ofgroupD1,D2,E1,E2,F1,F2 severally is 202.09Hu,215.87Hu,214.24Hu,219.70Hu,219.43Hu,224.08Hu,The CT value of the main portal has no difference in statistics(P＞0.05).Conclusion:When the contrast medium is 300mgI/ml and the injection rate of 3 or 4ml/s,The optimal scan delay time respectively is 42s,33s,When the contrast medium is 350mgI/ml and the injection rate of 3 or 4ml/s,The optimal scan delay time respectively is 43s,34s5 When the contrast medium is 370mgI/ml and the injection rate of 3 or 4ml/s,The optimal scan delay time respectively is50s,44s.when scanning with 64-rows CTP,we need wait 3-5s at the time of the time we got from the experiment,we can acquire the higher quality imagine displaying the grade5 or above branch of portal,it can meet with clinic needs on the whole.PART TWO:The clinical application of 64-rows spiral CT PortographyObjectives:To study the clinical application values of 64-rows spiral CT for the displays of normal anatomy and variation of hepatic portal vein,and to probe into the blood vessel appearance of liver and pancreas diseases with 64-SCTP.Methods and Materials:40 subjects of liver or pancreas disease who had no CT contraindication had abdomen MSCTP examination The collected raw data were delivered to work station for lamina reconstruction and MIP as well as VR reconstruction.Result:The portal and branches were charged unevenness in 12 cirrhosis and portal hypertension patients,The splenic vein(SV)were thickened obviously and blood vessle courses were stiff and twist.The branches of portal could only be displayed the 3^rdor 4^thgrade.The bypass circulations were established.The portal system vessle courses were nature as the normal group in 7 liver benign lesion patients,the portal were clear,vessle wall smooth.the portal displaced in some patients with large lesion,but the vessle walls were smooth.The branch of portal vein were compressed,shifted with narrowed caliber in 15 hepatocellular carcinoma patients.The brim of portal was dim,Tumor thrombosis,which appeared as low density defect in the involved veins,in 9 patients.6 patients with pancreatic carcinoma,MSCTP showed no main portal encroachment in 2 patients, and also showed pancreas and superior mesenteric vein had no edge in another 4 patient.Conclusion:64-rows spiral CT Portography can clearly show the normal anatomy and variation of the PV,the relation between the PV and the tumor in liver and pancreas,and the encroachment degree of the portal system.Therefore,64-rows spiral CT Portography is a promising clinical examination method which can provide more important information for surgery,interventional theraphy and liver transplantation.