家兔肝纤维化模型的建立及CT灌注成像

目的:评价CT灌注成像在肝纤维化中的作用.方法:建立家兔肝纤维化模型17只,分批分期行CT同层动态增强扫描,后取肝脏行病理检查,用去卷积数学方法中双输入-单室模型计算多个参数(肝动脉灌注量、门静脉灌注量、总肝灌注量、肝动脉灌注指数、分布容积、平均通过时间等),然后进行分组,用SPSS11.0统计软件分析.结果:发现CT灌注成像所有参数均无统计学差异,而仅仅表现为相对减少或增加的趋势.结论:CT灌注成像对肝纤维化的评价需进一步研究和探讨.     

肝脏及其相关脏器在肝炎后肝硬化中的时间-密度曲线研究

目的 探讨从正常肝脏到肝炎后肝硬化的演变过程中,相关脏器的时间-密度曲线(TDC)变化规律.资料与方法 3组共120例(正常对照组34例,肝炎肝纤维化组48例,肝炎后肝硬化组38例)经CT同层动态增强扫描得到腹主动脉、门静脉、肝实质、脾脏实质等4个感兴趣区(ROI)TDC,分析3组ROI达峰时间(TTP)和峰值高度(PV).结果 3组主动脉的TTP无差异性,PV有统计学差异;3组门静脉、肝脏、脾的,TTP及PV均有统计学意义,均为TTP渐延长,PV渐下降.结论 门静脉、肝脏、脾等相关脏器的TDC表现反映了肝炎后肝硬化的血流动力学变化.     

暂时阻断肝静脉后肝脏的血流改变及其意义：CT影像学研究

目的 研究犬肝静脉阻断后肝脏血流改变,并评估该技术在肝癌介入治疗中的应用价值。材料与方法 对6只犬行肝静脉球囊导管阻断,应用螺旋CT行肝脏双期扫描和同层动态增强扫描。结果 肝静脉受阻肝叶密度明显低于未阻肝叶,二者形成明显的分界,门静脉逆行增强显影,受阻肝叶肝实质及门静脉增强的平均峰值时间显滞后于未受阻者。结论 暂时阻断肝静脉后受阻区域总的血流量减少,血流速度变缓,门静脉变为引流静脉。暂时阻断肝静脉行肝动脉化疗栓塞术和局部高温固化疗效是一项有临床应用前景的技术。     

CT评价门静脉右支前间隙改变及与肝纤维化和肝硬化病理学分期的关系

目的：探讨肝门区门静脉右支前间隙改变与肝纤维化、肝硬化病理学分期的相关性。资料与方法对经病理穿刺活检证实的肝纤维化S1期（17例）、S2期（13例）、S3期（15例）、S4期（21例）和中晚期肝硬化（22例）患者及20例对照组患者行CT平扫和增强扫描,在CT增强图像上测量各组门静脉右支前间隙宽度,将所测结果与病理学分期进行相关性分析。建立ROC曲线用于门静脉右支前间隙改变判断S≥4即早期肝硬化的评价。结果门静脉右支前间隙从S3期开始至肝硬化期逐渐增宽,其中S4期门静脉右支前间隙增宽与对照组、S1~S3期组比较差异有统计学意义（P<0.05或P<0.01）,肝硬化期组与其他各组比较差异均有统计学意义（P<0.01)。Spearman等级分析显示门静脉右支前间隙变化与肝纤维化、肝硬化病理分期呈正相关（r=0.704, P<0.01)。ROC曲线显示CT测量门静脉右支前间隙判断S≥4的曲线下面积为0.897,最佳诊断宽度为≥10 mm,灵敏度和特异度分别为88.1%和71.4%。结论门静脉右支前间隙改变与肝纤维化、肝硬化病理学分期具有良好的相关性,通过CT测量门静脉右支前间隙改变有助于肝纤维化、肝硬化程度的判断,尤其是对早期肝硬化的诊断。     

肝硬化640层CT肝灌注容积扫描肝血管成像的临床应用研究

目的:探讨利用640层CT肝灌注容积数据对肝硬化患者进行肝血管成像的可行性及其临床应用价值.方法:25例肝功正常(A组)和50例肝硬化患者(B组:Child-Pugh A级25例;C组:Child-Pugh B级25例)行640层CT肝灌注检查,绘制时间-密度曲线(TDC),测量主动脉和门静脉的达峰值时间(TTP)、峰值(PV)及门静脉与肝脏密度差的最大值(P-L).选取主动脉峰值期的容积数据进行肝动脉血管成像;采用P-L值最大的1期及3期容积数据对门静脉进行单期和多期融合成像,并对比两种成像方法的图像质量.结果:三组间主动脉TTP和PV的差异均无统计学意义(P＞0.05).肝硬化组门静脉的TTP较对照组长,PV及P-L值下降,3组间差异有统计学意义(P＜0.05);进一步两两比较,除A与B组间门脉TTP值的差异无统计学意义外,其余各组间3个参数的差异有统计学意义(P＜0.05).3组均可显示肝动脉3级分支.门脉多期融合成像质量优于单期成像(P＜0.05),A组可显示3～4级门静脉分支,B和C组可显示1～3级门静脉分支.结论:利用640层CT全肝灌注成像容积数据进行血管成像,能清晰显示肝动脉和门静脉,有助于肝硬化患者临床治疗方案的制订.     

肝细胞外基质体积分数定量评价肝纤维化的诊断价值

目的 探讨肝细胞外基质体积分数(fECVs)在无创定量评价肝纤维化程度方面的诊断价值.方法 选取肝脏穿刺确诊肝纤维化并进行常规肝脏多期动态增强CT扫描患者60例,通过平扫及平衡期(注射对比剂3 min后)计算肝实质(Eliver)及主动脉(Eaorta)绝对强化值,并通过以下公式计算fECV值:fECV(％)=Eliver/Eaorta(100-Hct[％]),分析各纤维化组间fECV值差异及其与肝脏纤维化程度的相关性,采用受试者工作特征曲线分析fECV值诊断肝纤维化程度的能力.结果 肝纤维化分期组间fECV值比较差异具有统计学意义(P＜0.05),S0∶S4、S1∶S4及S2∶S4差异有统计学意义;fECV值与肝纤维化程度呈正相关(r=0.468,P=0.001);fECV值诊断重度肝纤维化及早期肝硬化(S≥3及S=4)的敏感性和特异性分别为76％、68％及89％、63％,受试者工作特征曲线下面积分别为0.757及0.775.结论 fECV值可以作为常规肝脏多期动态增强CT检查中无创性评估肝纤维化的方法.     

磁共振灌注成像对肝纤维化的实验性研究

目的:评价磁共振灌注成像在肝纤维化中的作用。方法:选取普通级36只家兔,随机分为一组对照组和三组实验组。对实验组家兔注射四氯化碳溶液,建立家兔肝纤维化模型,然后分组行磁共振灌注成像。磁共振灌注成像采用SE-EPI序列,通过软件处理后采集肝实质和门静脉的信号强度,计算出相对肝门静脉局部血流容积、相对肝门静脉局部血流量、平均通过时间、最大信号下降百分比和相对肝血流容积,每次试验结束后取肝脏行病理检查。对MR灌注参数与病理改变作统计学分析,统计学处理采用SPSS11.0统计软件包。结果:MR灌注成像参数中最大信号下降百分比在各组间分别为0.750±0.080、0.534±0.168、0.572±0.119及0.626±0.030。经统计学处理差异有显著性意义(P<0.05)。其他参数在各组之间有相对减少或增加的趋势,但无统计学意义。结论:MR灌注成像参数中仅最大信号下降百分比有统计学意义,但其对肝纤维化分期的价值尚需进一步的研究。     

正常肝脏和肝硬化门静脉高压患者CT增强扫描参数研究

目的 :探讨正常肝脏和肝硬化门静脉高压患者增强扫描参数对图像质量的影响。方法 :收集正常志愿者(60例)和肝硬化门静脉高压患者(90例),依据对比剂剂量、扫描时间,将正常志愿者分为常规组(A组)和大剂量组(B组),将肝硬化门静脉高压患者分为常规剂量常规扫描组(C组)、大剂量常规扫描组(D组)、大剂量延时扫描组(E组),每组各30例。获得双期图像后,测量动脉期肝动脉CT值,门静脉期门静脉、肝实质、肝静脉CT值及门静脉肝实质CT值差值,并对双期图像质量进行双盲目测评分。结果:A组与B组肝动脉、门静脉、肝静脉CT值及门静脉与肝实质CT值差值比较差异均有统计学意义(P0.05),肝实质CT值2组间比较差异无统计学意义;A组、B组图像质量评分差异无统计学意义。C组与D组比较,肝动脉、门静脉、肝实质、肝静脉CT值、门静脉与肝实质CT值差值差异有统计学意义(P0.05)。E组与D组比较,肝动脉、门静脉强化程度差异无统计学意义;肝静脉CT值、肝实质CT值上升,门静脉与肝实质CT值差值减小,差异有统计学意义(P0.05);C组、D组、E组图像质量评分差异有统计学意义(P0.05)。结论:当对比剂注射速率为3 m L/s时,正常人对比剂剂量为1.5 m L/kg体质量,动脉期扫描起始时间28 s,门静脉期扫描起始时间60 s,可获得较满意图像;肝硬化门静脉高压患者对比剂剂量为2.0 m L/kg体质量,动脉期扫描起始时间33 s,门静脉期扫描起始时间70 s,可获得较满意图像。     

多层面螺旋CT对肝移植术后肝动脉狭窄肝灌注的研究

目的　利用动态单层CT扫描对原位肝移植术后肝动脉狭窄肝灌注与未行肝移植、无肝脏病变者进行比较。资料与方法　对 30例肝移植术后肝动脉狭窄患者选取肝门 (包括肝、门静脉、主动脉和脾 )层面行动态单层CT扫描。高压注射器经肘静脉注射非离子型对比剂欧乃派克 4 0ml,流率 3ml/s,注射对比剂时即进行扫描 ,每间隔1s扫 1层 ,共扫描 35层。通过每一层面选定的ROI作CT值测量 ,绘制出时间 密度曲线 ,从而计算出相应灌注值并与未行肝移植、无肝脏病变者进行对照。结果　肝移植术后肝动脉狭窄 <5 0 %组 ,肝动脉灌注 (t=0 .5 ,P >0 .0 5 )、门静脉灌注 (t=1 ,P >0 .0 5 )与对照组间无显著差异 ;肝动脉狭窄≥ 5 0 % ,肝动脉灌注与对照组存在差异 (t =2 .1 4 ,P <0 .0 5 ) ,低于对照组 ,门静脉灌注与对照组有差异 (t=2 .6 3,P <0 .0 5 ) ,高于对照组。结论　肝移植术后肝动脉狭窄≥ 5 0 % ,肝动脉灌注降低而门静脉灌注升高。动态单层CT扫描对于评价肝移植术后肝脏灌注是有帮助的     

门静脉高压CT征象与肝纤维化、肝硬化病理分期关系的探讨

目的 探讨肝纤维化、肝硬化门静脉高压的CT征象与病理分期的关系.方法 对经肝穿刺病理活检确诊的肝纤维化S1期12例、S2期14例、S3期9例、S4期13例、典型肝硬化16例以及20例对照组行16层螺旋CT上腹部3期增强容积扫描,于门静脉期最大密度投影(MIP)图像上分别测量门静脉左支、门静脉右支、门静脉主干(MPV)、脾静脉(SV)和肠系膜上静脉(SMV)的管径,并观察各组门静脉侧支循环开放情况及有无腹水和脾脏肿大,将上述指标与病理分期作对照研究.门静脉系统各血管管径的比较采用单因素方差分析,组间两两比较用SNK法;多组腹水及侧支循环发生率的比较采用R×C表x2检验,组间行x2分割计算;运用Logistic回归分析探讨门静脉系统中对肝纤维化病理分期影响最大的血管.结果 对照组门静脉左支、门静脉右支、MPV、SV和SMV的管径分别为(0.98 ±0.11)、(1.00±0.12)、(1.33±0.11)、(0.75±0.10)和(1.07±0.12)cm,脾脏体积为(128.55±30.56)cm<'3>,无侧支循环开放和腹水.S1、S2、S3期组、S4期组或早期肝硬化组、典型肝硬化组SV管径逐渐增大,分别为(0.86±0.12)、(0.96±0.11)、(1.07±0.08)、(1.09±0.10)和(1.18±0.19)cm,各组与对照组间比较,差异均有统计学意义(P<0.05),重度肝纤维化(S3期组和S4期组)、典型肝硬化以及轻度肝纤维化(S1期组和S2期组)间差异均有统计学意义(P<0.05).Logistic回归分析显示,在门静脉各血管测量指标中,SV的标准化回归系数最大(2.719),且差异有统计学意义(P<0.01).典型肝硬化的侧支循环开放及腹水发生率明显高于正常肝脏和肝纤维化各期,S4期的侧支循环出现率明显高于对照组、S1期组及S2期组.结论 当慢性肝病发展至重度肝纤维化或早期肝硬化时,CT检查有助于早期诊断.     

Haemodynamic changes in the liver under balloon occlusion of a portal vein branch: evaluation with single-level dynamic computed tomography during hepatic arteriography

AIM: To assess haemodynamic changes in the liver under temporary occlusion of an intrahepatic portal vein. MATERIALS AND METHODS: Between February 2000 and October 2004, 16 patients with hepatobiliary disease underwent single-level dynamic computed tomography during hepatic arteriography (SLD-CTHA) under temporary balloon occlusion of an intrahepatic portal vein. All patients needed percutaneous transhepatic portography for therapy of their disease. SLD-CTHA was undertaken to clarify the time-attenuation curve influenced by portal vein occlusion, and it was performed continuously over a period of 30s. The difference in absolute attenuation of the liver parenchyma in segments with occluded and non-occluded portal vein branches was determined by means of the CT number, and the difference in absolute attenuation of the occluded and non-occluded portal veins themselves was also evaluated. RESULTS: SLD-CTHA demonstrated a demarcated hyperattenuation area in the corresponding distribution of the occluded portal vein branch. The attenuation of the liver parenchyma supplied by the occluded portal vein was significantly higher than that in the non-occluded area (p<0.01). The balloon-occluded portal branch enhancement in 15 of 16 cases (94%) appears due to arterio-portal communications. Failure to evaluate a remaining case for portal branch enhancement was due to absence of a visualized portal branch in the section. CONCLUSION: Under temporary occlusion of an intrahepatic portal vein, hepatic angiography produced enhancement of the occluded portal branches and their corresponding parenchymal distribution; this finding is considered consistent with the presence of arterio-portal communications.     

螺旋CT门静脉造影延迟时间的合理选择

应用时间－密度曲线选择螺旋ＣＴ门静脉造影的合理扫描延迟时间。材料与方法１４例正常人和１２例重度肝硬化患者于第一门水平行同层动态增扫描。造影剂量为２ｍｌ／ｋｇ体重,注射速率３ｍｌ／ｓ。经外周静脉注射造影剂后１５ｓ开始扫描,以后每隔５ｓ扫描１次,持续至１２０ｓ。分别测同一层面门静脉,肝脏,脾脏的ＣＴ值,并计算各时间各时点民肝脏的密度差,描绘时间－密度曲线,结果正常组与肝硬化组门静脉平均强化峰值和达到时     

Usefulness of saline pushing in reduction of contrast material dose in abdominal CT: evaluation of time-density curve for the aorta, portal vein and liver

The effects of saline pushing after contrast material injection were investigated as well as the possibility for this technique to reduce contrast material doses in liver CT examinations. 52 patients were divided randomly into three groups: 100 ml of contrast material (300 mg I ml(-1)) only (A; n = 19), 100 ml of contrast material pushed with 50 ml of saline solution (B; n = 17), and 85 ml of contrast material pushed with 50 ml of saline solution (C; n = 16). Single-level images were obtained at the level of the main portal vein after the initiation of contrast material injection. There were no significant differences in the mean peak enhancement values (PE) and the mean time to peak enhancement values (TPE) of the aorta between the three groups. The mean PE of the portal vein in group B increased 21 HU over that in group A (p<0.05), and there was no significant difference between groups A and C. The mean PE of the liver in group B increased 7 HU over that in group A (p<0.05), and there was no significant difference between groups A and C. The mean TPE of the portal vein was shorter by 4 s (p<0.05), and that of the liver was shorter by 5 s (p<0.05) in group C compared with those in group A. In conclusion, saline pushing increases the enhancement values of the portal vein and liver, and allows a contrast material dose reduction of 15 ml without decreasing hepatic and vascular enhancement at adequate scan timing.     

Hepatic enhancement in multiphasic contrast-enhanced MDCT: comparison of high- and low-iodine-concentration contrast medium in same patients with chronic liver disease

OBJECTIVE: The aim of this study was to evaluate the degree of hepatic enhancement and image quality in patients with cirrhosis or chronic hepatitis who underwent multiphasic contrast-enhanced dynamic imaging on MDCT at least twice using standard (300 mg I/mL) and higher (370 mg I/mL) iodine concentrations in contrast medium during follow-up periods. MATERIALS AND METHODS: This study included 20 patients with chronic liver diseases who underwent at least two multiphasic contrast-enhanced dynamic MDCT examinations using 100 mL of standard (300 mg I/mL = group A) and higher (370 mg I/mL = group B) iodine concentrations in contrast medium. After we obtained unenhanced CT scans, we performed multiphasic scanning at 30 sec (arterial phase), 60 sec (portal phase), and 180 sec (late phase) after the start of contrast medium injection. The CT values of hepatic parenchyma, abdominal aorta, and portal vein were measured. The mean enhancement value was defined as the difference in CT values between unenhanced and contrast-enhanced images. Visual image quality was also assessed on the basis of the degree of hepatic and vascular enhancement, rated on a 4-point scale. RESULTS: The mean hepatic parenchyma enhancement values in group B was significantly greater (p < 0.001) than those in group A during the portal phase (43.8 +/- 8.2 H vs 36.2 +/- 7.3 H) and the late phase (33.7 +/- 7.0 H vs 27.3 +/- 3.9 H), but the difference on the arterial phase images between the two groups (9.4 +/- 3.2 H vs 8.3 +/- 2.5 H) was not significant. The mean aorta-to-liver contrast during the arterial phase in group B was significantly higher (p < 0.001) than that in group A (236 +/- 40 H vs 193 +/- 32 H). For qualitative analysis, the mean visual scores for hepatic parenchyma and vasculature enhancement in group B were significantly higher than those in group A in arterial phase (p < 0.018), portal phase (p < 0.0001), and late phase (p < 0.0001). CONCLUSION: In the same patients with chronic liver diseases, a higher iodine concentration (370 mg I/mL) in the contrast medium improves contrast enhancement of liver parenchyma in the portal phase and late phase images, improves overall image quality, and helps improve diagnostic accuracy for liver diseases on multiphasic contrast-enhanced dynamic MDCT.     

Late-arterial and portal-venous phase imaging of the liver with a multislice CT scanner in patients without circulatory disturbances: automatic bolus tracking or empirical scan delay?

The value of automatic bolus tracking in late-arterial and portal-venous phase imaging of the liver with a multislice CT scanner as compared with fixed time-delay examination in patients without circulatory disturbances is evaluated. For the evaluation of known or suspected liver disease, 98 multiphase contrast-enhanced CT examinations including double late-arterial phase imaging were randomized into either scanning with a scan delay of 30 s from the beginning of contrast material injection or scanning with automatic bolus tracking. Contrast material was injected at 0.07 ml/kg body weight/s over 30 s. Contrast enhancement in each acquisition was measured in the aorta, portal vein, liver, pancreas and hepatocellular carcinomas. The density difference between hepatocellular carcinomas and the hepatic parenchyma was calculated. The mean time to the first-pass acquisition as determined by automatic bolus tracking was 29.6 s. No statistically significant difference was observed between the two groups either in any enhancement in any acquisition or in the lesion-to-liver density difference. The use of automatic bolus tracking in late-arterial and portal-venous phase hepatic CT does not significantly improve the degree of contrast enhancement in the aorta, portal vein, liver and pancreas or lesion-to-liver conspicuity in patients without circulatory disturbances.     

正常肝脏与肝硬化螺旋CT扫描时对比剂最优化使用方法的研究

目的 研究正常肝脏与肝硬化肝脏在螺旋CT增强多期扫描中最佳对比剂剂量、注射流率及各组织强化达到峰值的时间。方法 正常肝脏、肝硬化肝脏各60例，按完全随机设计法各分成6组，分别以不同的注射剂量及流率在肘静脉注射非离子型对比剂，并在同一层面作连续多层扫描。最后测量各组织CT值，建立统计表并相互比较。结果 正常肝脏当注射剂量为1.5ml/kg时，3种不同的注射流率除主动脉强化峰值两两比较统计学上差异均有显著性意义外（P＜0．05），门静脉、肝实质差异均无显著性意义（P＞0．05）；当注射流率为2.5ml/s时，不同的剂量强化峰值主动脉、门静脉、肝实质差异均有显著性意义（P＜0．05）。肝硬化组：当注射剂量为2.0ml/kg时，3种不同的注射流率时肝实质在2.5ml/s与3.0ml/s时强化峰值差异有显著性意义（P＜0．05）。当注射流率为3.0ml/s时，不同的剂量肝实质强化峰值差异有显著性意义（P＜0．05）。结论 正常肝脏与肝硬化肝脏的螺旋CT增强扫描的最佳剂量、注射流率应分别为1.5ml/kg、2.5ml/s和2.0ml/kg、3.0ml/s。其主动脉、门静脉及肝实质达到峰值的时间分别为：28s、52s、73s和31s、68s、77s。     

肝局灶性病变CT与MRI动态增强对照研究

目的:探讨肝局灶性病变在CT和MRI动态增强中的影像差异及其原因,以提高对CT及MRI各自动态增强表现的认识。方法:搜集17例肝脏局灶性病变患者的临床资料,其中7例肝细胞肝癌,5例海绵状血管瘤,2例腺瘤,2例局灶结节性增生,1例转移瘤。全部病例均分别行CT及MRI的平扫和三期动态增强扫描;MRI采用SE序列加快速扰相梯度回波序列,将CT和MR动态增强图像进行对照观察,包括动态增强各期的强化范围、强化方式和强化幅度,强化幅度的比较用病灶密度(信号)与肝脏密度(信号)的比值进行比较。结果:肝癌、腺瘤和局灶结节性增生在CT与MRI上强化范围相似。1例肝癌动脉期强化幅度MRI大于CT,3例肝癌和2例局灶结节性增生门脉期及延迟期强化幅度MRI大于CT,2例腺瘤增强各期强化幅度MRI均大于CT,以动脉期差异最大。5例海绵状血管瘤强化范围动脉期及门脉期MRI大于CT,延迟期则相仿。1例转移瘤CT增强各期均未见明显强化,MRI门脉期及延迟期可见环状强化。结论:肝局灶性病变CT与MRI动态增强表现存在一定的差异,主要表现为部分病变增强各期强化幅度MRI大于CT,尤以动脉期差异最大;部分病变增强范围MRI大于CT。     

应用DSA、CT和经肠系膜上动脉门静脉灌注CT成像研究肝转移瘤的血液供应

目的 探讨DSA、CT和经肠系膜上动脉门静脉灌注CT成像对肝转移瘤的血液供应显示状况.方法 回顾性分析100例原发病灶经手术和(或)病理证实的肝转移瘤患者资料,均进行了CT平扫、多期CT增强扫描、选择性腹腔动脉和超选择性肝固有动脉DSA检查,其中,56例还经肠系膜上动脉插管行肠系膜上动脉的门静脉灌注CT成像(P(1TAP)检查,计算转移瘤中心区域、肿瘤边缘、门静脉和正常肝实质的时间-密度曲线(TDC)灰度密度(K值),观察肝转移瘤血液供应来源.DSA图像用Photoshop软件进行定量分析,CT图像用去卷积灌注软件进行分析.结果 DSA表现:肝固有动脉造影TDC显示肿瘤中心K值峰值平均为(67±12)%,肿瘤边缘K值峰值平均为(76±15)%,正常肝实质K值峰值平均为(51±10)%.腹腔动脉造影TDC显示,肿瘤中心及肿瘤边缘K值表现为快速上升,然后为缓慢上升的平台,而正常肝实质则呈现持续缓慢上升的态势.PCTAP扫描表现:肿瘤在30 s的时间内,密度变化几乎呈直线,无增强表现.结论 肝动脉是肝转移瘤的主要血液供应来源,门静脉几乎不参与肝转移瘤血液供应.