原位肝移植术前受体血管和肝实质的一次性MRI评价

目的:探讨在MR 3D序列中应用GRAPPA技术对原位肝移植受体血管及肝实质实行一次性评价的可行性及临床应用价值.方法:20例接受原位肝移植的受体术前接受MR检查,常规2D平扫后,利用GRAPPA技术一次屏气完成3D FLASH和3D VIBE增强扫描,利用3D FLASH原始图像和重建图像分析肝动脉、门脉及肝静脉解剖及病理情况,与手术结果对照,利用3D VIBE序列图像评价肝实质强化及病灶检出情况,结果与手术标本对照.结果:19例患者检查成功.肝动脉解剖变异2例,9例可见门脉病理改变(包括侧支循环形成,门脉癌栓),4例患者可见下腔静脉及肝静脉内栓子形成,2例可见右副肝静脉,上述血管情况与手术结果符合;20例患者于3D VIBE序列中有16例达到优化动脉期的要求,HCC病灶检出准确率达到80%.结论:联合应用GRAPPA技术和3D序列对原位肝移植受体血管及肝实质实行一次性评价是可行的,并且为临床前选择合适受体提供了更多有价值的信息.     

多层螺旋CT对肝移植受体手术前后评估

目的探讨多层螺旋CT血管造影（MSCTA）对原位肝移植受体手术前后的评估. 资料与方法对14例临床拟行肝移植受体进行MSCT多期增强扫描,并行2D、3D血管重建,观察肝脏、血管情况.5例行原位肝移植手术患者的MSCTA图像与手术对照分析. 结果 14例患者的肝脏病变及肝动脉和门静脉系血管结构清晰显示,其中肝硬化6例,肝硬化合并肝癌5例,Budd-Chiari综合征1例,Budd-Chiari综合征合并肝硬化1例,Budd-Chiari综合征合并小肝癌1例. 肝动脉解剖走行常见型11例,变异3例,腹腔干狭窄2例,肝动脉狭窄1例,脾动脉瘤1例.显示门静脉系血栓5例,门脉高压侧支循环形成6例;胆管结石3例.5例肝移植受体术前门脉癌栓1例,门脉高压侧支循环形成3例,术后未发现并发症. 结论 MSCTA对肝移植受体术前术后提供更多准确的信息,具有很好的应用前景.     

三维动态增强磁共振血管成像在肝移植术前的应用

 目的探讨三维动态增强磁共振血管成像(3D DCE MRA)三期扫描技术,评价其在肝移植术前的诊断价值.方法对拟进行肝移植的183例患者进行术前3D DCE MRA成像扫描,采用Siemens Symphony 1.5T超导MRI扫描机,圆形极化相控阵体线圈,3D DCE MRA三期(动脉期、门脉期和静脉期)扫描技术,即对所得图像进行综合评价.结果全部病例均获得了满意的血管成像图像,肝动脉可显示2～3级分支,门静脉可显示2～5级分支,肝静脉可显示1～2级分支.183例肝移植患者,5例显示肝动脉变异,其中2例起自肠系膜上动脉,2例直接起自腹腔干,1例起自胃左动脉.单纯肝硬化门脉高压103例,其中,冠状静脉和食道胃底静脉曲张23例、脐周静脉曲张5例、肠系膜静脉曲张2例、脾门周围静脉曲张30例,门静脉玻璃样变性1例;原发性肝癌79例,5例肝动脉包埋、僵直、推移,2例肝内动-静脉瘘,门静脉右支癌栓23例,门静脉左支癌栓7例,门静脉主干癌栓3例,同时发生门静脉左右支癌栓的2例,MRA表现为门静脉呈半月形或杯口形缺损或不显影.7例肝静脉出现栓塞,5例下腔静脉受压推移,1例下腔静脉瘤栓.结论 3D DCE MRA三期扫描能很好的显示肝动脉、门静脉、肝静脉及下腔静脉系统病变,肝移植术前应用3D DCE MRA,基本达到临床要求,是术前血管评估的有效方法.     

MRI在肝移植中的应用

目的评价MRI检查在肝移植术前术后的应用价值。方法将我院2004-01—2005-03收治的22例肝移植患者术前MRI检查结果与手术、病理检查相比较,术后MRI检查与其它影像学检查相比较。结果22例肝移植患者中,肝硬化并门脉高压15例,肝硬化、肝癌6例,严重肝损伤1例;门静脉栓子5例,其中4例为癌栓,1例是管壁样组织,肝右静脉及下腔静脉瘤栓1例;副肝动脉2例,分别发自腹腔干及肠系膜上动脉;胆管吻合口狭窄或胆漏3例;肝动脉可显示2~3级分支,门静脉可显示2~4级分支,肝静脉可显示1~2级分支,胆管显示2~3级分支。结论MRI对肝移植术前和术后的评估具有很大的价值。     

多层面CT在肝移植受体术前评估中的应用

目的:探讨多层面CT在肝移植受体术前评估中的应用价值.材料和方法:我们总结分析了自2003年11月至2004年8月52例接受多层面CT检查的晚期肝病患者.采用薄层动态增强扫描,横断面图像 CT血管造影技术,评估肝脏实质病变及血管变异情况.结果:其中接受肝移植手术26例,其中有6例肝动脉变异,与术前判断完全吻合.5例门脉癌栓形成及5例血栓形成中各有1例误诊.结论:多层面CT是一种快捷、无创、价廉的检查手段,可为肝移植受体术前评估提供详尽且准确的解剖及病变信息.     

64层螺旋CT结合后处理技术对肝移植术后并发症的评估

目的:探讨64层螺旋CT结合后处理技术在肝移植术后评估的应用价值.方法:选取50例(男40例、女10例)肝移植术后患者,行64层螺旋CT平扫、四期增强扫描及CTA检查,由两位放射科医师对图像进行评估,内容包括肝实质、血管、胆道情况及有无转移.将结果与彩超及临床随访行对照分析.结果:CT检查示:肝动脉并发症3例、门脉并发...     

多层面螺旋CT肝动脉血管成像参数的研究及肝移植术后肝动脉评价

目的　系统分析主要扫描参数对CT血管成像图像质量的影响 ,寻找可获得较好图像质量的扫描参数组合 ,并对肝移植术后肝动脉进行评价。方法　应用不同扫描参数分别对随机选取的 45例腹部增强扫描病人进行扫描 ,高压注射器经肘静脉注入非离子型对比剂欧乃派克 1.3ml/kg体重 ,3ml/s注入速度 ,延时时间 18～ 2 0s,扫描完成后于GEAdvantageWindows 4.0工作站上进行 2D及 3D血管成像。通过观察管壁清晰度、伪影及肝动脉分支情况评价肝动脉CTA图像质量 ,系统分析主要扫描方式对肝动脉CTA图像质量的影响 ,寻找可获得良好图像质量的扫描参数组合。利用此扫描参数组合对 48例肝移植术后病人进行检查 ,并与DSA检查相对照。结果　①采用探测器组合 3 .75mm× 4 11.2 5mm床速的组合方式 ,HQ扫描模式 ,重叠重建率 70 %及STD重建方式进行扫描和重建可获得表面光滑、伪影不明显、形态不失真的肝动脉CTA图像。②采用此扫描参数组合评价 48例肝移植病人术后肝动脉CTA与DSA具有相同的准确性。结论　多层面螺旋CT血管成像可清楚显示正常肝动脉的情况 ,可达肝动脉 3级分支血管 ,并可准确评价肝移植术后肝动脉情况     

肝移植术后磁共振propeller LAVA薄层动态增强技术及MRCP的诊断价值

目的 探讨磁共振propeller LAVA和MR胰胆管成像(MRCP)对原位肝移植术后移植肝及其血管、胆管并发症、门静脉高压血液动力学变化的诊断价值.资料与方法 11例原位肝移植术后患者均用MRI常规序列扫描(Fiesta、Dual-Echo、FSPGR,FS FSE RT,DWI)及propeller LAVA薄层动态增强、MRCP检查,利用图像工作站对MRCP及propeller LAVA原始图像进行多平面重组(MPR),最大密度投影(MIP)等图像后处理.结果 (1)移植肝:肝实质动脉期异常灌注5例;肝淋巴回流受阻3例,肝局灶性坏死、肝包膜下少许积血、炎性病变、胆汁瘤形成各1例;(2)血管并发症:肝动脉吻合口狭窄3例,肝动脉略迂曲2例,移植动脉迂曲、节段性管腔狭窄2例,移植血管、门静脉吻合口狭窄各1例;(3)门静脉高压血流动力学变化:脾大5例,肝脾包膜下少量积液3例,合并脾包膜下灶性梗死1例,脾静脉、食管胃底静脉轻度曲张4例,脾肾分流1例,胃-肾静脉分流1例;(4)胆管并发症:缺血性胆管炎4例,胆总管吻合口狭窄7例,合并肝内胆管炎6例,胆囊管残端囊性扩张3例,胆总管多发小结石1例.结论 结合常规MRI,propeller LAVA和MRCP作为无创性"一站式"影像检查方法,在肝移植术后临床诊断及治疗方案的制定中具有重要价值.     

三维动态增强磁共振血管造影在肝移植中的初步应用

目的　探讨三维动态增强磁共振血管造影 (threedimensionaldynamiccontrast -enhancedMRangiography ,3DDCEMRA)技术 ,初步评估其在肝移植术前准备中的应用价值。方法　对 8例患严重肝脏疾病 ,临床上拟行肝移植的患者 ,术前行MRI平扫及 3DDCEMRA检查 ,对所得图像进行综合评价。所有病例均行多普勒超声 (DUS)检查 ,4例成功行肝移植手术。结果　所有病例均获得了满意的血管图像 ,肝动脉可显示 2～ 3级分支 ,门静脉可显示 2～ 5级分支 ,肝静脉可显示 1～ 2级分支。其中 3例肝硬化显示胃底食道静脉曲张 ,1例多囊肝显示肝动脉、门静脉受压移位。结论　 3DDCEMRA是一种有效的、无创的技术 ,对临床医师进行肝移植病人术前血管评估有很大的帮助     

多层螺旋CT双期血管造影对肝移植受体术前评估

目的 :探讨多层螺旋CT血管造影 (MSCTA)对肝移植受体的术前评估。方法 :对临床上拟为肝移植受体的80例患者用容积再现 (VR)法进行双期CT血管重建 ,观察腹腔动脉干及其分支 (肝总动脉、胃左动脉、脾动脉 )、肠系膜上动脉、门静脉血栓及侧支循环血管 ,依据Michels标准进行肝动脉解剖分型 ,与Michels的 2 0 0例尸体解剖结果间的差异进行 χ2 检验。 16例行肝移植手术患者的MSCTA图像与手术结果进行对照分析。结果 :MSCTA清晰显示了 80例患者的肝动脉和门脉系血管结构 ,其中 62例 (77.5 % )肝动脉解剖为常见型 ,18例 (2 2 .5 % )肝动脉解剖为变异型 ,此结果和Michels的结果间差异有显著性意义 (P <0 .0 5 ) ,15例显示门静脉血栓 ,6例显示腹腔干狭窄 ,2例显示脾动脉瘤 ,2例显示肝动脉细小。 16例肝移植术受体的血管结构术前得到很好的显示。结论 :MSCTA作为无创性的检查方法 ,在血管方面能为肝移植受体提供综合的术前评估。     

Utilizing generalized autocalibrating partial parallel acquisition (GRAPPA) to achieve high-resolution contrast-enhanced MR angiography of hepatic artery: initial experience in orthotopic liver transplantation candidates

OBJECTIVE: To evaluate feasibility of using GRAPPA to acquire high-resolution 3D contrast-enhanced MR angiography (CE-MRA) of hepatic artery and value of GRAPPA for displaying vessels anatomy. MATERIALS AND METHODS: High-resolution CE-MRA using GRAPPA was performed in 67 orthotopic liver transplantation recipient candidates. Signal intensity (SI) and relative SI, i.e., Cv-ro (vessel-to-liver contrast) of the aorta and the hepatic common artery (HCA), were measured. The SI and the relative SI were compared and analyzed using T-test. For purpose of qualitative evaluation, the vessel visualization quality and the order of depicted hepatic artery branches were evaluated by two radiologists independently and assessed by weighted kappa analysis. The depiction of hepatic arterial anatomy and variations was evaluated, and results were correlated with the findings in surgery. RESULTS: The mean SI values were 283.29+/-65.07 (mean+/-S.D.) for aorta and 283.16+/-64.07 for HCA, respectively. The mean relative SI values were 0.698+/-0.09 for aorta and 0.696+/-0.09 for HCA, respectively. Homogeneous enhancement between aorta and HCA was confirmed by statistically insignificant differences (p-values were 0.89 for mean SI values and 0.12 for mean relative SI values, respectively). The average score for vessel visualization ranged from good to excellent for different artery segments. Overall interobserver agreement in the visualization of different artery segments was excellent (kappa value>0.80). The distal intrahepatic segmental arteries were well delineated for majority of patients with excellent interobserver agreement. Normal hepatic arterial anatomy was correctly demonstrated in 53 patients, and arterial anomalies were accurately detected on high-resolution MRA image of all 14 patients. CONCLUSION: High-resolution hepatic artery MRA acquired using GRAPPA in a reproducible manner excellently depicts and delineates small vessels and can be routinely used for evaluating OLT candidates.     

血管性介入在肝脏移植中的应用

目的探讨血管性介入技术在肝脏移植前后诊治中的应用。方法对2003年1月~2005年2月对拟行肝脏移植的30例患者术前行肝动脉、肠系膜上动脉选择造影及经肠系膜上动脉间接门静脉造影;并对6例肝脏移植术后怀疑血管并发症的患者行造影及介入下溶栓及内支架治疗。结果30例患者术前造影中提示肝癌11例;4例患者动脉造影显示动脉血管变异。29例患者间接门脉造影成功,其中2例肝癌患者发现门脉癌栓,26例存在不同程度的静脉曲张。对6例怀疑胆道和血管并发症的患者作血管造影及相关介入治疗。其中2例成功行狭窄动脉吻合口金属内支架治疗,1例行动脉溶栓治疗,造影显示肝动脉血流恢复通畅;其他3例介入治疗效果不满意。结论血管造影能够提供准确的动脉和门静脉解剖和变异信息;血管介入技术有助于对肝移植术后早期血管并发症诊断和处理。     

Multidetector computed tomography for preoperative assessment of hepatic vasculature and prediction of splenic artery steal syndrome in patients with liver cirrhosis before transplantation

The purpose of this study was to evaluate the accuracy of MDCT for preoperative assessment of hepatic vascular anatomy and the identification of liver-transplantation (OLT) patients at risk of developing subsequent splenic artery steal syndrome (SASS). A total of 145 patients with liver cirrhosis who had undergone OLT and had pre-operative three-phase MDCT (4- to 64-rows) within 100 days before OLT were enrolled retrospectively. MDCT and 3Ds were reviewed by two independent blinded observers (O1/O2). Pre-operative imaging findings were correlated with intra-operative results; findings indicative for SASS were correlated with clinical data and DSA. Among all 145 patients, 16 patients (11%) showed accessory hepatic arteries (accuracy O1/O2, 97%; with 3Ds, 100%); 32 (22%) patients had replaced hepatic arteries (accuracy O1, 97%; O2, 95%; with 3Ds, 100%; κ?=?0.87 and 0.89, P?<?0.001). Among 119 patients, 12 patients developed SASS after OLT. The logistic regression model revealed the spleen volume (P?=?0.0105) as a predictive factor of SASS. With spleen volumes ≥829 ml, an accuracy of 75% for prediction of SASS was obtained. MDCT with three-dimensional post-processing (3Ds) was highly accurate for pre-operative hepatic vessel evaluation in patients before OLT. In addition, spleen volume was a predictive factor for developing SASS after OLT.     

Living related liver transplantation: preoperative magnetic resonance imaging for assessment of hepatic vasculature of donor candidates

Purpose: To evaluate the accuracy of magnetic resonance angiography (MRA) for preoperative assessment of hepatic vascular anatomy in liver donors before living related liver transplantation.

Material and Methods: A total of 55 consecutive living liver donors (mean age 42 years, range 18-68 years) underwent multiphase contrast-enhanced MRA of the hepatic vessels. Two readers categorized vessel visualization on a five-point scale and recorded vascular anatomy or variations thereof for the arterial, portal venous and venous systems. All 55 living liver donors subsequently underwent right hemihepatectomy for hemiliver donation, and preoperative MRA results were correlated with surgical findings.

Results: Overall vessel visualization assessment demonstrated good or very good ratings for the majority of patients. For hepatic arteries, the mean score was 4.4±0.8 (mean±standard deviation), and for the portal venous and venous systems it was 4.6±0.7 and 4.3±0.8, respectively. Among all 55 donors, 16 (29%) demonstrated accessory or replaced hepatic arteries, and seven (13%) and 20 (36%) donors had surgically relevant portal vein (trifurcation or early right posterolateral branching types) and hepatic vein variations, respectively. Correlation coefficients between MRA and surgery were 0.94, 1.00 and 0.91 for hepatic arteries, portal veins and hepatic veins, respectively.

Conclusion: In the preoperative evaluation before living related liver donation, contrast-enhanced MR angiography was a highly accurate, noninvasive tool for visualizing the hepatic vasculature and variations thereof in liver donor candidates.     

Effect of vessel size on creation of hepatic radiofrequency lesions in pigs: assessment of the "heat sink" effect.

OBJECTIVE: The effect of vessels and their size on radiofrequency lesion creation in the liver was evaluated with respect to potential for vascular injury and perfusion-mediated "heat sink" effect. SUBJECTS AND METHODS: Radiofrequency lesions targeted to tissue adjacent to a variety of vessels were created in vivo in the liver of 10 Yorkshire pigs. Postablation contrast-enhanced CT and then histopathologic analysis of the vessels and lesions were performed after sacrifice of the pigs. Degree of vascular injury and viability of perivascular hepatocytes were recorded and tabulated according to vessel size for both CT and histologic data sets. RESULTS: At CT, 42 (95%) of 44 veins greater than 3 mm remained patent, and four (20%) of 20 veins less than 3 mm were occluded. Heat sink effect, indicated by invagination of enhancing tissue between vessel and radiofrequency lesion, was observed in 32 (73%) of 44 veins greater than 3 mm and in zero of 20 veins less than 3 mm. On histopathology, 111 (100%) of 111 vessels less than 3 mm showed at least partial vessel wall injury, characterized by endothelial cell necrosis and luminal thrombus. In 24 vessels greater than 3 mm, the extent of vessel wall injury decreased with increasing vessel diameter. Viable perivascular tissue indicative of heat sink effect was identified in 12 of 24 veins greater than 3 mm, increasing to seven of seven veins greater than 5 mm. None of 96 vessels less than 2 mm and three of 111 vessels less than 3 mm showed any heat sink effect. CONCLUSION: There appears to be a narrow transition zone for hepatic vessels at 2-4 mm, beyond which the heat sink effect was seen consistently and substantial vascular injury was rare.     

Noncontrast 3D steady state free precession magnetic resonance angiography of the thoracic central veins using nonselective radiofrequency excitation over a large field of view: initial experience

PURPOSE: To evaluate the feasibility of three-dimensional (3D) steady state free precession (SSFP) magnetic resonance angiography (MRA) using nonselective radiofrequency excitation for the assessment of thoracic central veins. MATERIALS AND METHODS: Thirty consecutive patients (17 males, 13 females, age range 22-76) with various cardiac and thoracic vascular diseases underwent free-breathing electrocardiogram-gated noncontrast SSFP MRA and conventional high-resolution 3D contrast-enhanced (CE) MRA of the thorax at 1.5 T. Two readers evaluated both datasets for findings: venous visibility and sharpness (from 0, not visualized to 3, excellent definition); artifacts; signal-to-noise ratio (SNR); and contrast-to-noise ratio (CNR) in 8 venous segments including superior vena cava (SVC), supra-diaphragmatic inferior vena cava, bilateral brachiocephalic, proximal subclavian, and lower internal jugular veins. Statistical analysis was performed using Wilcoxon test for overall image quality and vessel visibility, t test for SNR and CNR analysis, and kappa coefficient for inter-observer variability. RESULTS: 3D SSFP and CE-MRA were successfully performed in all patients. Scan time for SSFP MRA ranged from 5 to 10 minutes (mean +/- standard deviation, 7 +/- 2 minutes). Reader 1 (2) graded the overall image quality as excellent and good on SSFP MRA in 23 (25) and 7 (5) patients, and on CE-MRA in 22 (23) and 8 (9) patients, respectively. On SSFP MRA, readers 1 and 2 graded 234 (97.5%) and 233 (97.1%) venous segments with diagnostic definition (grades 2 and 3) (kappa = 0.69), respectively. On conventional CE-MRA, readers 1 and 2 graded 231 (96.3%) and 232 (96.7%) venous segments with diagnostic definition (grades 2 and 3) (kappa = 0.68), respectively. Segmental visibility and sharpness were higher for lower internal jugular veins on CE-MRA for each reader (P < 0.001). No significant difference existed for venous visibility and sharpness scores for other venous segments between the 2 techniques for both readers (P > 0.05). SNR and CNR values were lower for internal jugular veins on SSFP MRA (P < 0.001). No significant difference existed between SNR and CNR values for the other venous segments on SSFP and CE-MRA (P > 0.05 for all). The 2 readers demonstrated patent SVC Glenn shunt to main pulmonary artery (n = 3), patent extra cardiac Fontan shunt from inferior vena cava to pulmonary artery confluence (n = 2), and dilatation and thrombosis of SVC (n = 1) and right brachiocephalic vein (n = 1) on both datasets. CONCLUSION: Free breathing navigator-gated noncontrast 3D SSFP MRA with nonselective radiofrequency excitation provides high image quality and sufficient SNR and CNR for confident evaluation of thoracic central veins.     

MR angiography of the pedal arteries with gadobenate dimeglumine, a contrast agent with increased relaxivity, and comparison with selective intraarterial DSA

PURPOSE: To compare gadobenate dimeglumine (Gd-BOPTA)-enhanced MR angiography (i.e., contrast-enhanced MRA [CE-MRA]) of the pedal vasculature with selective digital subtraction angiography (DSA) in patients with peripheral arterial occlusive disease (PAOD). MATERIALS AND METHODS: A total of 22 patients with PAOD were prospectively examined at 1.5T. For contrast enhancement, 0.1 mmol/kg body weight of Gd-BOPTA were applied. MRA consisted of dynamic imaging with acquisition of six consecutive data sets. Acquisition time for each data set was 24 seconds, voxel size was 1.0 x 1.0 x 1.3 mm(3). A total of 20 out of 22 patient underwent selective DSA, two patients fine-needle DSA. DSA and MRA were performed within seven days. Image analysis was independently done by two observers with assessment of overall image quality, motion artifacts, detection of patent vessel segments of the distal calf and pedal vessels, and the number of patent metatarsal arteries. After four weeks, a consensus reading of DSA images was done. A second consensus reading of CE-MRA was performed after a further six weeks. RESULTS: Consensus readings of MRA and DSA revealed higher image quality and fewer motion artifacts for MRA (P = 0.021 and P = 0.008, respectively, sign test); interobserver agreement was good (kappa = 0.78) for image quality, and moderate (kappa = 0.46) for motion artifacts. There were no differences between CE-MRA and DSA in detecting patent vessel segments with a high degree of agreement (kappa = 0.89), and interobserver agreement for MRA was substantial (kappa = 0.89). Significantly more vessels were assessed as partially occluded on DSA than on CE-MRA (P = 0.004). There was a good agreement between DSA and CE-MRA for assessment of relevant vessel stenosis (kappa = 0.61); interobserver agreement for MRA was good (kappa = 0.65). CE-MRA detected significantly more patent metatarsal arteries than did DSA (P < 0.001). CONCLUSION: Gd-BOPTA-enhanced MRA is comparable to DSA for assessment of the pedal vasculature, and is able to delineate significantly more patent vessels without segmental occlusions and more metatarsal arteries than selective DSA.     

Low-dose, time-resolved, contrast-enhanced 3D MR angiography in cardiac and vascular diseases: correlation to high spatial resolution 3D contrast-enhanced MRA

AIM: To evaluate the effectiveness of low-dose, contrast-enhanced, time-resolved, three-dimensional (3D) magnetic resonance (MR) angiography (TR-MRA) in the assessment of various cardiac and vascular diseases, and to compare the results with high-resolution contrast-enhanced MRA (CE-MRA). MATERIALS AND METHODS: Thirty consecutive patients underwent contrast-enhanced 3D TR-MRA and high spatial resolution 3D CE-MRA for evaluation of cardiac and thoracic vascular diseases at 1.5 T, and neurovascular, abdominal and peripheral vascular diseases at 3T. Gadolinium-based contrast medium was administered at a constant dose of 5 ml for TR-MRA, and 20 ml (lower extremity 30 ml) for CE-MRA. Two readers evaluated image quality using a four-point scale (from 0=excellent to 3=non-diagnostic), artefacts and findings on both datasets. Interobserver variability was tested with kappa coefficient. RESULTS: The overall image quality for TR-MRA was in the diagnostic range (median 0, range 0-1; k=0.74). Readers demonstrated important additional dynamic information on TR-MRA in 28 of 30 patients (k=0.84). Confident evaluation of organ perfusion (n=23), arteriovenous malformation/fistula flow patterns (n=7), exclusion of intra-cardiac shunts (n=6), and assessment of stent and conduit patency (n=5) were performed by both readers using TR-MRA. Readers demonstrated fine vascular details with higher confidence in 10 patients on CE-MRA. Using CE-MRA, Reader 1 and 2 depicted anatomical details in 6 and 5 patients, respectively, only on CE-MRA. CONCLUSION: Low-dose TR-MRA yields rapid and important functional and anatomical information in patients with cardiac and vascular diseases. Due to limited spatial resolution, TR-MRA is inferior to CE-MRA in demonstrating fine vascular details.     

CE-MRA在腹部静脉病变中的应用及诊断价值

目的探讨腹部静脉病变的CE-MRA的表现及临床应用价值。方法回顾性分析47例腹部静脉病变的常规MRI和腹部静脉CE-MRA表现。结果门脉高压28例(肝硬化性22例,非肝硬化性6例),其中1例合并静脉瘤;静脉内瘤栓8例;肿瘤性静脉包绕4例;布-加氏综合征(Budd-chiarrisyndrome,BCS)2例,门静脉海绵状变性(非肿瘤性)2例,肝移植术后3例。CE-MRA清楚显示了门静脉、脾静脉、胃冠状静脉的增粗,食道胃底静脉的曲张;瘤栓所致的腔内低信号区;静脉被肿物推移受压的情况;门静脉、肝静脉、下腔静脉的狭窄、闭塞和侧枝循环的分布范围和程度。常规MRI显示了腹部脏器的原发病变。结论CE-MRA结合常规MRI检查对腹部静脉病变有一定的诊断价值,对临床治疗方案的选择有明确的指导意义。     

3D CE-MRA在评价腹部静脉系统中的应用

目的探讨三维增强磁共振血管成像（3DCE—MRA）技术在腹部静脉系统中的应用价值。方法收集具有完整资料的16例病例，先行常规MRI检查，随后经静脉注射Gd—DTPA20—30mL后连续三次行3DCE—MRA采集数据，对静脉系统原始图像进行MIP重建。主要观察指标为下腔静脉、脾静脉、肝静脉、肠系膜上静脉、门静脉形态变化。结果16例患者中，门腔静脉正常者9例，3DCE—MRA清晰显示下腔静脉、肝静脉、脾静脉、肠系膜上静脉、门静脉结构；门静脉高压3例，示脾静脉增宽迂曲，门静脉主干增宽及明显侧支循环形成；2例布加氏综合征；1例下腔静脉血栓形成；1例门静脉海绵样改变。结论3DCE—MRA是一种安全、敏感性高的血管造影技术，可提高腹部静脉系统疾病的术前诊断。