电影相位对比与屏气二维相位对比MRI对肝硬化门静脉血流的对照研究

目的探讨MRI电影法相位对比（Cine PC）与屏气二维相位对比（2D PC）在肝硬化患者和正常志愿者门静脉血流测量中的诊断价值。资料与方法对照组为82名志愿者,男45名,女37名,平均年龄26.65岁;肝硬化组24例,男14例,女10例,平均年龄42.00岁。空腹状态下采用CinePC技术对门静脉血流定量测量,同期采用2DPC技术3种不同屏气状态（正常吸气屏气,呼气屏气,平静呼吸屏气）与其进行比较。结果肝硬化患者门静脉血流速度较对照组略减低,除2D PC平静呼吸法,余方法两组差异均无统计学意义,肝硬化组门静脉血流量与对照组比较明显增大（P〈0.01）,但2DPC吸气屏气技术两者差异无统计学意义。采用相关性分析对屏气2DPC（不同呼吸状态）与Cine PC MRI方法定量门静脉血流速度、血流量,显示两种技术相关性很好（r〉0.8;P〈0.01）,但在对照组行相关性分析,仅呼气后屏气2D PC与Cine PC显示中度相关（r〉0.5;P〈0.01）,吸气后屏气与CinePC相关性较差（r〈0.4）。结论MRI Cine PC在正常呼吸情况下对门静脉血流行定量测量,接近人体生理状态,适合门静脉血流测量;正常呼吸状态屏气对肝硬化患者门静脉血流影响较正常人小,在肝硬化血流测量中,MRI Cine PC与屏气2DPCMRI法显示很好相关性。屏气2DPCMRI技术提供了一种简便、实用、相对准确的肝硬化门静脉血流测量方法。     

磁共振电影相位对比定量肝硬化门静脉血流与肝功能分级的关系

目的 采用电影相位对比磁共振成像(Cine PC MRI)评价肝硬化门静脉高压患者门静脉血流动力学与Child-Pugh肝功能分级的关系. 资料与方法 49例肝硬化门静脉高压患者,男26例,女23例,平均年龄47.8岁;19名正常对照者,男10名,女9名,平均年龄43.5岁.按Child-Pugh肝功能分级,A级10例,B级31例,C级8例.采用Cine PC MRI对门静脉血流进行定量测量. 结果 肝硬化组按照Child A、B、C顺序,门静脉血流速度逐渐降低,组内差异具有显著性统计学意义(P<0.05);Child C级的门静脉流速与A、B级及正常组相比,流速明显减低,差异具有显著性统计学意义(P<0.01).肝硬化Child B、C级患者较正常组门静脉直径增宽、截面积明显增大(P<0.05).Child C级较B级门静脉血流量明显减少(P<0.05). 结论 Cine PC MRI监测门静脉血流动力学有助于评价肝硬化患者的肝功能、门静脉高压严重程度.     

电影相位对比MRI肝硬化上消化道出血门静脉血流动力学研究

目的:采用电影相位对比MRI定量肝硬化门静脉血流,评价其与消化道出血的关系.方法:对49例门静脉高压症患者行电影相位对比MRI门静脉血流定量测量,依照病史分为出血组31例,无出血组18例;另选对照组19例.结果:门静脉高压出血组及未出血组门静脉主干截面积与正常组比较均显示明显增大(P＜0.05),肝硬化出血组门静脉流速较未出血组流速增高,但较正常对照组减低,该差异无统计学意义(P＞0.05),肝硬化出血组门静脉血流量明显增高,与正常组及肝硬化未出血组比较,差别具有统计学意义(P＜0.05).结论:电影相位对比MRI能客观反映门静脉血流动力学改变.     

后循环缺血的MR电影相位对比法血流定量研究

目的:探讨MR电影相位对比法测量后循环缺血患者双侧椎动脉血流流速、血流量等血流动力学参数的准确性及后循环缺血的原因。方法:28例经临床诊断为后循环缺血的患者及5例同年龄组健康志愿者,使用头部线圈和周围脉搏门控技术,采用MR电影相位对比法测量双侧椎动脉的血流动力学参数,并与经颅多普勒(TCDU)检查,结果进行比较,同时分析椎动脉血流量与血管狭窄程度的相关性。结果:MR电影相位对比和TCDU两种技术所测量的双侧椎动脉流速呈高度相关(左侧r=0.887,P=0.013;右侧r=0.785,P=0.027)。MR电影相位对比法测得病变组左右椎动脉平均流速分别为(16.16±7.99)和(15.72±9.92)cm/s,平均血流量分别为(66.63±45.23)和(68.57±38.84)ml/min。MR电影相位对比法所测血流量正常对照组与后循环缺血组之间差异有统计学意义。椎动脉血流量与血管狭窄程度无明显相关性(r=-0.144,P=0.654)。结论:使用MR电影相位对比法可无创性准确评价后循环缺血患者血流动力学改变,后循环的平均椎动脉血流量与血管狭窄程度低度相关。     

磁共振团注追踪技术测定门静脉血流的评价

目的　探讨磁共振团注追踪技术 (bolustrackingtechnique ,BTT)的原理及其临床应用价值。资料与方法选择 10例正常志愿者 ,利用BTT测量门静脉主干的血流峰值流速、流量和流向 ,并与彩色多谱勒超声测量结果作对照 ,评价该方法测量的准确性。结果　BTT法测量正常志愿者空腹门静脉主干的血流平均峰值流速为 14.66±4.0 6cm/s,平均单位时间峰值流量为 10 5 5 .40± 63 2 .95ml/min ,与彩色多谱勒结果的相关系数为 0 .90 9,P =0 .697,在统计学上 ,两者无显著性差异。所有血流均为向肝流向。结论　磁共振BTT是一种无损伤、准确地测量血管内血流流速、流量和流向的影像技术     

横窦血液流量MR测量方法的比较研究

目的 通过与电影相位对比（PC）法和超声的比较，评价二维（2D）PC法测量横窦血液流速和流量的准确性。方法 （1）志愿者8例，共计测量12个横窦，在每个横窦相同层面上分别采用2DPC法和电影PC法进行血流信号面积，血液流速和流量测量，测量结果用配对t检验进行统计分析。（2）需要开颅手术患者5例。共计6个横窦，术前采用2DPC方法对横窦血液流速进行测量，术中暴露横窦以后，用TCD探测血液流速，测量结果采用相关回归分析。结果 统计结果表明：2DPC法和电影PC法测得的横窦血流信号面积（t=-1.106,P=0.293)。流速（t=0.262,P=0.798)和流量（t=0.439,P=0.669)均无显著性差异，2DPC测得的流速与TCD测得的流速相关性良好（y^=1.303x 0.62,r^2=0.88)。结论 2DPC法是测量横窦血液流量简便实用的方法。     

高血压病左心房相位容积功能的电影MRI评价

目的　评价电影MRI对高血压病 (EH)左心房相位容积功能测量的价值。方法　应用梯度回波电影程序对 3 0例健康志愿者和 3 0例EH患者进行左室及左房成像。应用多普勒超声频谱测量二尖瓣血流的流速时间积分 (VTI)。对两种方法的相应指标进行相关性分析。结果　EH患者左房最大容积、最小容积、收缩前容积、收缩排血量、射血分数和左房对左室充盈作用的比率(AC % )明显增高。左房储备容积降低而其占总功能容积的比例无显著差异。左房导流容积及其占总功能容积的比例明显降低。电影MRI测定的AC %与多普勒方法测定的VTIA VTItotal %间具有显著的直线相关性。结论　梯度回波电影MRI为EH左房相位容积功能提供了一种准确的测量手段 ,它可用于EH的检查和随访。     

三维门静脉血流动力学的正常表现及其在肝硬化病人中的改变

目的以多普勒超声(US)为参考标准,对肝硬化病人、健康且年龄相匹配的受试者和健康年轻志愿者行3个方向流速编码的时间分辨三维(3D)相位对比MR成像[流动敏感的四维(4D)MR成像],比较病人影像间的差异,以研究肝硬化病人的三维门静脉血流动力学的改变。材料与方法该     

非等势椎动脉MR血流定量测量

目的 探讨非等势椎动脉两侧血管血流量测量的意义.方法 对52例非等势椎动脉和30例等势椎动脉正常志愿者双侧椎动脉内血流进行MR相位对比电影法扫描,并通过流速分析软件测定流量.结果 等势椎动脉组右侧、左侧平均 血流量为(1.45±0.42) ml/s、(1.47±0.52) ml/s,平均峰值血流量为(2.18±0.69) ml/s、(2.24±0.74) ml/s.非等势椎动脉组优势侧、劣势侧平均血流量为(1.69±0.39) ml/s、(1.09±0.36) ml/s,平均峰值血流量为(2.92±0.85) ml/s、(1.81±0.77) ml/s.结论 非等势椎动脉血流量的测量对病变定位、定性具有重要的意义.     

肺动脉流速的MRI测量与多普勒超声比较研究

目的探讨相位对比法MR I(PC-MR I)测量肺动脉血流的准确性以及临床应用价值。方法①选取正常健康志愿者42例,随机分为2组,采用PC-MR I和多普勒超声测量了主肺动脉的内径、最大流速和平均流速。②采用公式分别计算出主肺动脉1个心动周期的血流量。结果①PC-MR I和多普勒超声测量主肺动脉的内径分别为(24.4±3.41)mm和(21.5±2.55)mm。②PC-MR I测量主肺动脉的最大流速和平均流速分别为(79.9±24.0)cm/s和(50.3±7.71)cm/s。③多普勒超声测量主肺动脉的最大流速和平均流速分别为(88.8±8.33)cm/s和(53.7±5.04)cm/s。④PC-MR I测量主肺动脉的血流量为(73.5±6.60)m l,多普勒超声测量主肺动脉的血流量为(69.0±10.6)m l。应用统计学方法成组样本均数t-检验分析2种测量结果,选择检验水平为α为0.05。结论PC-MR I可以准确测量肺动脉的血流速度和血流量,对评价肺动脉血流动力学的改变具有一定价值。     

Evaluation of extrahepatic portal hypertension and surgical portal systemic shunts by intravenous CT portography

The purpose of this study was to evaluate the splenoportal (SP) axis and patency of portal systemic shunts in extrahepatic portal venous obstruction (EHO) by intravenous CT portography (CTP). Fifty-five patients of preshunt EHO, and 21 patients of postshunt (surgical portal systemic shunts) EHO, were subjected to intravenous CTP on a subsecond helical CT scanner. Thin, axial sections and three dimensional (3-D) reconstructions, including maximum intensity projection (MIP) and shaded surface display (SSD), were obtained. The findings were correlated with Color Doppler Flow Imaging (CDFI). In the EHO preshunt group, the site of the block demonstrated on CTP correlated with CDFI in 53 of 55 cases. In the postshunt group, shunt patency evaluation by CTP was in agreement with CDFI in 19 of 21 patients (8 patent; 13 blocked). Two patients in each group could not be evaluated on CDFI, while CTP could provide the appropriate information. There was no false positivity or negativity with CTP in patients evaluated on both modalities. The etiology of EHO, the global view of collaterals, and the 3-D anatomy of SP axis could be well depicted and was well accepted by the surgeons. We conclude that CTP is an impressive new technique that can effectively evaluate pre- and postshunt cases of EHO.     

Gallbladder varices: A potential collateral pathway in portal hypertension and portal vein occlusion

Varices of the gallbladder were demonstrated angiographically in four patients. One patient who had had a mesocaval shunt developed gallbladder varices as a result of hepatoportal shunting. Three patients had gallbladder varices owing to collateral circulation from portal vein occlusion.     

Transjugular intrahepatic portocaval shunt after thrombus disruption in partially thrombosed portal veins

Portal vein (PV) thrombosis increases the risk of variceal bleeding in cirrhotic patients with portal hypertension. Its presence also complicates PV access during transjugular porto-caval shunt (TIPS) placement. We overcame this obstacle by using ultrasound (US) guidance for PV entry. Clot disruption by balloon catheters was then performed before placing the vascular endoprostheses for portal-venous shunting. We treated 3 cirrhotic patients in such fashion with good clinical results. Portal thrombi progressively disappeared after shunting due to both balloon disruption and the rise in portal blood flow velocity.     

Unusual right umbilical vein collateral in portal hypertension

Umbilical vein collaterals frequently occur in patients with portal hypertension, with the vessels usually connected to the oeft portal system. An umbilical vein collateral draining the right intrahepatic portal system was found in a patient with portal hypertension. This observation has not been previously reported and probably represents persistence of the embryonic right umbilical vein.     

Transjugular Intrahepatic Portosystemic Shunt Placement in Patients with Cirrhosis and Concomitant Portal Vein Thrombosis

Purpose To determine the safety and efficacy of transjugular intrahepatic portosystemic shunt (TIPS) creation in patients with liver cirrhosis complicated by thrombosed portal vein. Methods This study reviewed 15 cases of TIPS creation in 15 cirrhotic patients with portal vein thrombosis at our institution over an 8-year period. There were 2 women and 13 men with a mean age of 53 years. Indications were refractory ascites, variceal hemorrhage, and refractory pleural effusion. Clinical follow-up was performed in all patients. Results The technical success rate was 75% (3/4) in patients with chronic portal vein thrombosis associated with cavernomatous transformation and 91% (10/11) in patients with acute thrombosis or partial thrombosis, giving an overall success rate of 87%. Complications included postprocedural encephalopathy and localized hematoma at the access site. In patients with successful shunt placement, the total follow-up time was 223 months. The 30-day mortality rate was 13%. Two patients underwent liver transplantation at 35 days and 7 months, respectively, after TIPS insertion. One patient had an occluded shunt at 4 months with an unsuccessful revision. The remaining patients had functioning shunts at follow-up. Conclusion TIPS creation in thrombosed portal vein is possible and might be a treatment option in certain patients.     

Preoperative portal vein embolization using an amplatzer vascular plug

The purpose was to evaluate the safety and efficacy of preoperative portal vein embolization (PVE) using an Amplatzer vascular plug (AVP). Forty-one patients who underwent PVE using gelatin sponge particles and the AVP were enrolled. The right portal branches were embolized using gelatin sponges (1–8 mm³) through a 5-F catheter, and the AVP was deployed at the first- or second-order right portal vein. Technical success and complications, recanalization, and changes of total estimated liver volumes (TELV), future liver remnant (FLR), and FLR/TELV were evaluated. Follow-up CT performed 6–43 days (median, 16 days) after PVE was used to evaluate volume parameters. PVE was technically successful in 40 of 41 patients. Major complications occurred in two patients, with one each having extensive portal vein thrombosis and liver abscess. Partial recanalization of the occluded portal vein was seen in one patient. The mean FLR volume (653 ± 174 ml vs. 532 ± 154 ml, p < 0.001) and mean FLR/TELV ratio (43 ± 8% vs 36 ± 7%, p < 0.001) were significantly higher after than before PVE. PVE using the AVP seems to be a relatively safe and effective technique for inducing hypertrophy of the FLR with minimal risk of recanalization.     

多层螺旋CT对门静脉海绵样变的诊断价值

目的:分析门静脉海绵样变(CTPV)的多层螺旋CT(MSCT)表现和特征,探讨MSCT对该病的诊断价值.方法:使用16排MSCT对30例CTPV患者,行上腹部CT平扫、动态增强扫描,采用多平面重组(MPR)、最大密度投影(MIP)、容积再现 (VR)等图像后处理技术显示异常的门静脉及侧枝血管情况.结果:CTPV的MSCT平扫示门静脉结构不清,肝门区可见多发的结节状软组织影.增强扫描示动脉期10例有肝实质灌注异常;门静脉期18例患者门静脉主干和(或)左右分支增粗,内可见充盈缺损,4例门静脉显示不清;8例门静脉主干和(或)左右分支在正常范围内;1例门静脉主干变细.胆管周围静脉丛(100%)、胆囊静脉(60%)及胃左静脉(23.3%)呈点状、簇状扩张.MPR、MIP、VR可直观地显示各曲张血管的走行及曲张程度.结论:MSCT及图像后处理系统对CTPV诊断具有重要价值,门静脉栓塞及其周围纡曲扩张的侧枝静脉为其特征性表现.     

Hepatopetal collaterals after portal vein thrombosis following liver transplantation

Two liver transplant patients with hepatopetal collaterals after portal vein thrombosis are described. Angiographically, the appearance is similar to cavernous transformation of the portal vein. The demonstration of hepatopetal collaterals is diagnosic of portal vein occlusion from whatever cause. After portal vein occlusion, collaterals develop from preexisting periportal vessels which undergo compensatory enlargement and reconstitute the intraheptic portal vessels. In liver transplant patients, the collateral communications must arise de novo, since all potential collateral pathways are severed at the time of transplantation.