【作者】 肖杰；

【导师】 韩萍；

【作者基本信息】 华中科技大学 ， 影像医学与核医学， 2006， 硕士

【摘要】 第一部分多层螺旋CT门静脉成像不同注射流率及重建方法的研究目的(1)对比研究双相注射方式(注射流率3.5ml/s,1.0ml/s)与单相注射方式(注射流率3.5ml/s)多层螺旋CT门脉成像质量;(2)比较不同重建方法在门脉高压时显示侧支血管的能力。材料和方法30例经临床检查确诊的门静脉高压患者行MDCTP检查,患者扫描前口服600ml温水充盈胃和十二指肠。随机将患者分为A组(n=15)和B组(n=15),A组采用双相注射方式,第一期以注射流率3.5ml/s至16-18s,1.0ml/s注射流率维持至门脉期开始扫描;B组采用单相注射方式,即以3.5ml/s注射流率,对比剂剂量1.5-2.0ml/kg。A组与B组门脉期描延迟时间为45-50s。准直器宽度0.75mm,床进15mm/360。,螺距为1.25, 120kv,250mAs。层厚1mm、层间距0.5mm的轴位图像采用MIP、MPR及VR图像后处理,分别显示门静脉主干、脾静脉、肠系膜上静脉和胃冠状静脉等门静脉主要属支和侧支循环血管(食管、胃底静脉丛、胃短静脉、脐静脉、脾/胃-肾分流等)。(1)对照分析A与B组的图像质量指标,包括:同一层面门脉主干与肝脏实质密度差、分支显示级别。然后计算A,B组相应得分,进行配对t检验。(2)统计MIP及VR重建显示不同类型侧支血管的数目,以门脉期成像所得薄层CT横断位图像及MPR重组图像作为参考,进行配对x2检验,比较不同重建方法显示侧支血管的能力。结果(1)A组与B组门静脉成像质量两指标之间的差异无显著性意义(t值分别为1.632和1.578,P值均>0.05),A组造影剂用量少于B组。(2)MIP、VR成像时侧支血管显示率分别为87.6%和72.3%,其差异具有显著性意义(x2=6.13 P<0.05)结论(1)双相注射方式(注射流率3.5ml/s 1.0ml/s)减少对比剂用量并具有良好图像质量。(2)MDCTP在显示门脉高压的侧支血管时,图像后处理方法中首选MIP成像,辅以VR成像。第二部分MDCTP对门脉高压侧支循环血管影像学表现及临床价值的研究目的评价多层螺旋CT门静脉成像(MDCTP)在门脉高压侧支循环血管显示的影像学表现及临床价值。材料和方法31例经临床检查确诊的门静脉高压患者行MDCTP检查,其中10例患者又进行了DSA直接门脉造影。患者扫描前口服600ml温水充盈胃和十二指肠。15例采用双相扫描方式,即第一期以注射流率3.5ml/s至16-18s,1.0ml/s注射流率维持至门脉期开始扫描;B组采用单相注射方式,即以3.5ml/s的流率团注,对比剂剂量1.5-2.0ml/kg。门脉期扫描延迟时间为45-50s。准直器宽度0.75mm,床进15mm/360。,螺距为1.25, 120kv,250mAs。采集层厚1mm、层间距0.5mm的轴位图像采用MIP、MPR、VR图像后处理,分别显示门静脉主干、脾静脉、肠系膜上静脉和胃冠状静脉等门静脉主要属支和侧支循环血管(食管、胃底静脉丛、胃短静脉、脐静脉、脾肾静脉、胃肾静脉等)。10例患者MDCTP与DSA直接门脉造影作比较,分析门脉主干、肝内左右分支的开放性及侧支循环发生情况,分析两者符合情况。结果MDCTP不仅显示肝内门静脉4-5级分支,还显示了整个门脉侧支血管系统。31例患者中,胃左静脉曲张28例,食管或食管旁静脉曲张27例,脾静脉曲张21例,胃短/胃后静脉曲张7例,脾-肾分流血管1例,脐静脉曲张伴腹壁静脉曲张2例,门静脉栓塞伴海绵样变4例,肠系膜上静脉血管闭塞2例。10例MDCTP在显示门静脉主干、侧支血管和多数近端门静脉肝内分支方面同DSA直接门静脉造影相符合。MDCTP显示2例脐静脉开放,DSA直接门脉造影未显示。2例患者行介入治疗前、后MDCTP显示侧支血管及其治疗后再通情况,与DSA直接门静脉造影相符。结论MDCTP能显示门静脉高压侧支血管开放的部位、范围及程度,有助于对门脉高压患者治疗方案的选择,也可做为门脉高压治疗后疗效随访手段,是一种可供选择的无创性门脉检查方法。更多还原

【Abstract】 Objective: (1) To discuss the feasibility of dual flow rates ( 3.5ml/s ,1.0 ml/s )injection method in reducing the dosage of contrast agent without compromise to the resulted image quality.,compared to single flow rate( 3.5ml/s) injection method(2) compare the display of the collaterals by VR,MIP , referring to the axial source and MPR images. Material and Methods: 30 patients with documented portal hypertension in clinics underwent MDCTP, who were divided into group A(n=15) and B(n=15) randomly.Prior to scanning , 600ml of plain water were administered orally as a negative contrast to distend the stomach and duodenum. scanning was performed at dual flow rates of 3.5ml/s for 16-18s and 1.0 ml/s until portal phase started in group A .a flow rate of 35.ml/s in group B, injection contrast dosage was 1.5-2.0 ml/kg. Portal phase scanning was started 45-50s after injection。Technical parameters were as follows: collimation 0.75mm, table feed 15mm/360。,pitch 15,120kv,250mAs. Post-processing techniques such as MIP,MPR and VR were applied to display the collaterals . Paired t-test was carried out between group A and B, concerning on 2 indexes (density difference between portal vein and liver parenchyma at same slice, distal branches display). Referring to the display of thin axial and MPR images, counting the numbers of collaterals visualized by post-processing methods, compared the visualization capability between VR and MIP using paired- x2 test.Results: (1)No significant differences were indicated between 2 indexes(PV-L density difference, and portal branches display) of group A and B(t values were 1.632 and 1.578, respectively,P >0.05),the dosage contrast in group A was less than that in group B .(2) the visualization rates of MIP and VR were 87.6 % and 72.3%,respectively, significant difference was indicated(x2=6.13 P<0.05) Conclusion: (1) Method of dual flow rates( 3.5ml/s ,1.0 ml/s )injection reduced the dosage of contrast agent without compromise to image quality.(2) VR and MIP were preferred in MDCTP visualization of collaterals , MIP provided better reconstructed images, combined with VR ,referring to axial and MPR images when necessary diagnosis Part two Evaluation of Portal System and its Collateral in Portal Hypertension using Multi-detector row Spiral CT PortographyObjective: To evaluate the value of multi-detector row spiral CT portography(MDCTP) findings in demonstrating portal system and its collaterals in portal hypertension. Material and Methods: MDCTP was performed in 31 patients with documented portal hypertension in clinics, prior to scanning , 600ml of plain water were administered orally as a negative contrast to distend the stomach and duodenum. scanning was performed at dual flow rates of 3.5ml/s for 16-18s and 1.0 ml/s for portal inflow phase in 15 cases , single flow rate of 3.5ml was applied in 16 cases. Technical parameters were as follows: collimation 0.75mm, table feed15mm/360。, pitch 15,120kv, 250mAs. Post-processing techniques such as MIP,MPR and VR were applied to display the collaterals . Findings of MDCTP in 10 patients were compared with those from DSA direct portography.Results: MDCTP simultaneously depicted fourth or fifth branches of the intrahepatic portal veins and entire portosystemic collaterals. on MDCTP images ,left gastric varicose were seen in 28 patients, esophageal and paraesophageal varicose in 27, splenic varicose in 21 , short gastric veins or posterior gastric veins in 7,splenorenal shunts in 1,abdominal wall and umbilical varicose in 2, portal venous thrombosis in 4,SMV thrombosis in 2 .With demonstration of portosystemic collaterals in 10 cases ,MDCTP showed results similar to those of DSA direct portogaphy, on portal vein, proximal intrahepatic branches and collaterals, except 2 umbilical varicose displayed by MDCTP were ignored in DSA direct portography, and also provided the similar results of emboli zed or recanalized collaterals to DSA direct portography in 2 interventional therapy cases.Conclusion: MDCTP provide the accurate information of the collateral circulations and the post-operative follow-up examination in patients with portal hypertension, It becomes an alternative method for non-invasive and valuable portography.更多还原