3D-DCE MRA在左肾静脉压迫综合征的临床应用

目的:探讨三维动态增强磁共振血管成像(3D-DCE MRA)对左肾静脉压迫综合征的临床应用价值。方法:对6例胡桃夹现象患者及10例健康人行3D-DCE MRA成像检查。利用原始数据采用最大强度投影(MIP)技术进行图像重组,测量肠系膜上动脉与腹主动脉之间的夹角及左肾静脉扩张段与狭窄段的比值,观察睾丸静脉或卵巢静脉有无曲张。结果:3D-DCE MRA图像能清晰显示肠系膜上动脉、腹主动脉与左肾静脉的解剖关系及全貌。6例胡桃夹现象患者肠系膜上动脉与腹主动脉夹角(平均30°)变小,正常对照组其夹角>60°,两组比较差异有统计学意义(t=2.157,P<0.05)。6例胡桃夹现象患者均可见左肾静脉不同程度扩张及狭窄,左肾静脉扩张段与狭窄段内径的比值平均为4.8,而正常对照组左肾静脉肾门前段与肠系膜上动脉和腹主动脉夹角段血管内径的比值为1.5.两组比较差异有统计学意义(t=2.342,P<0.05)。6例胡桃夹现象患者中3例睾丸静脉曲张,1例卵巢静脉曲张,而对照组中生殖腺静脉无1例显示。结论:3D-DCE MRA可作为诊断胡桃夹现象的首选方法。     

3D DCE MRA在诊断Budd-Chiari综合征中的应用价值

目的评价三维对比动态增强磁共振血管成像(3D DCE MRA)在诊断Budd-Chiari综合征(BCS)中的价值。方法8例BCS术前接受了常规MRI和3D DCE MRA检查,着重于回顾性分析其3D DCE MRA表现。结果8例3D DCE MRA检查显示下腔静脉阻塞3例,下腔静脉和肝静脉阻塞5例。下腔静脉阻塞部位在肝段5例、膈段1例及膈上段2例,阻塞表现形式包括膜性1例及节段性7例。伴有肝静脉阻塞的5例中肝静脉开口处阻塞3例,肝静脉分支阻塞2例。8例中有5例显示肝内侧枝循环,包括肝包膜下静脉侧枝循环、叶间静脉侧枝循环及肝内未定型侧枝循环。8例均显示肝外侧枝循环,包括深层静脉侧枝循环、中层静脉侧枝循环、浅层静脉侧枝循环及门静脉侧枝循环。8例BCS的其他征象包括肝实质信号异常、肝脏形态改变、下腔静脉内血栓形成、脾大、腹水及胸水。结论3D DCE MRA在诊断BCS中具有很高的价值,是诊断和治疗前后全面评价BCS的无创性血管成像技术。     

门静脉3D DCE MRA成像的价值与常规门静脉造影对照研究

与常规门静脉造影对照,评价门静脉三维动态态增磁共振血管成像（３－ｄｉｍｅｎｓｉｏｎａｌｄｙｎａｍｉｃｃｏｎｔｒａｓｔｅｎｈａｎｅｄＭＲＡ,３ＤＤＣＥＭＲＡ）显示门静脉开放性及侧支循环的能力。材料与方法：共有２０例患者做了门静脉ＤＤＣＥＭＲＡ成像,分析门静脉３ＤＤＣＥＭＲＡ上门脉主干,肝内门脉     

3D DCE MRA在原发性肝癌诊断中的临床应用

目的：探讨单次屏气三维对比增强磁共振造影(3D DCE MRA)在原发性肝癌中的检查技术及临床应用。方法：回顾性分析23例原发性肝癌的3D DCE MRA表现。对原发性肝癌肝动脉期、门静脉期分别进行扫描和重建。结果：肝动脉期可显示肝癌供血动脉血管7例，动静脉瘘6例，肝动脉受挤压变形6例。门静脉期显示门静脉高压18例。门静脉癌栓13例，肝内门静脉受压移位3例。结论：有效地抓住对比剂在各靶血管中的有效浓度，可分别显示肝癌的血供情况、血管破坏情况、门静脉开放程度，为临床治疗提供有价值的影像参考。     

DCE MRA对主动脉夹层的诊断价值

目的　评价动态增强磁共振血管成像对主动脉夹层诊断价值及对临床治疗的指导作用。方法　 2 0例不同类型的主动脉夹层患者 ,应用动态增强磁共振血管成像技术扫描 ,并与手术结果对照 ,分析DCEMRA的图像质量及其对血管的显示情况。结果　 2 0例均获得满意图像 ,不但可清晰地显示主动脉夹层的真假腔和内膜片 ,并可确定破口大小、数量及位置以及血流动态情况。结论　动态增强磁共振血管成像是诊断主动脉夹层准确、快速、无创和首选的影像学检查方法 ,具有较高的临床应用价值     

3D DCE MRPA诊断肺栓塞的临床应用研究

目的 :探讨三维动态增强磁共振肺动脉血管成像 (3DDCEMRPA)诊断肺动脉栓塞的价值及限度。方法 :先行MR平扫 ,然后应用快速梯度回波 (FFE)序列对 3 8例怀疑肺栓塞的患者进行 3DDCEMRPA扫描。参数为TR 9ms ,TE 3ms ,矩阵 2 5 6× 12 8,翻转角 2 0° ,对比剂Gd DTPA 0 .2mmol/kg快速注射。结果 :被确诊为肺栓塞的 3 0例患者 ,共发现栓塞 43处 ,其中 3例伴有肺动脉高压。肺栓塞的 3DDCEMRPA的直接征象为肺动脉内充盈缺损 (中心型、部分型、附壁型 )和肺动脉截断 (杵状、平直、锥形及鼠尾状截断 ) ;间接征象为栓塞所属肺野出现梗死灶 ,近心侧肺动脉增粗等肺动脉高压征象及少量胸腔积液。结论 :3DDCEMRPA对中心、叶和段的肺动脉栓塞的诊断价值较大 ,但它对段以下动脉栓子的显示尚有一定限度 ;3DDCEMRPA还是鉴别急性肺动脉高压 (肺栓塞引起 )和慢性肺动脉高压的一个安全有效的手段。     

3D DCE MRA在肝血管血流流速测定的临床研究

近年来,随着磁共振新技术的发展,三维动态增强磁共振血管成像(Three-dimensional dynamic contrast-enhanced magnetic resonance angiography, 3D DCE MRA)技术逐渐成为体部血管成像的主要方法[1],它可以多角度、多方位显示肝内血管的解剖关系,同时,采用血流动力学自动分析软件测量肝内血管的血流速度、直径、血流量等指标,为临床提供一个更全面更为客观的诊断信息[2,3].     

非对比剂增强MRA在肾静脉血管成像中的应用价值

目的:评估多反转脉冲空间标记(SLEEK)非对比剂增强磁共振血管成像(NCE-MRA)技术对显示肾脏肿瘤患者肾静脉的可行性及静脉内瘤栓的诊断效能.方法:纳入行手术治疗的肾脏肿瘤患者共32例,所有患者均知情同意,32例患者均行SLEEK序列扫描,获取双肾静脉及下腔静脉原始图像.对70支肾静脉及32支下腔静脉的原始图像、最大密度投影(MIP)图像、多平面重建图像进行评估,包括图像质量、瘤栓显示,以病理结果为金标准,评估SLEEK对瘤栓显示的准确度、敏感度及特异度.结果:非肿瘤侧肾静脉(34支)图像质量评分均在2分及以上,肿瘤侧97.2％(35/36)的肾静脉图像质量评分在2分及以上.1支肿瘤侧肾静脉显示差,不足以用于诊断,对余下肿瘤侧肾静脉及下腔静脉以病理为金标准进行评估,SLEEK显示16支肾静脉有瘤栓,14支下腔静脉有瘤栓,病理均证实;SLEEK显示无瘤栓的静脉病理中亦未发现瘤栓.SLLEK诊断准确度、敏感度及特异度均为100％.两位医师评分及诊断的一致性较好,Kappa值均＞0.75.结论:SLEEK可准确诊断肾脏肿瘤患者静脉内瘤栓存在情况,并可多角度观察瘤栓范围,从而指导临床手术方案的选择.     

三维DCE MRA在门静脉和肝脏静脉系统的应用

目的探讨门静脉和肝脏静脉系统三维动态增强磁共振血分成像（3DDCEMRM）检查的最佳技术，评价3DDCEMRA在该系统中的使用价值。方法门静脉和肝脏静脉系统行3DDCEMRA108次，二维（2D）DCEMRA10次。比较两种力法显示门静脉右支的能力，不同层厚对3DDCEMRA显示门静脉右支的影响，并对门静脉、肝静脉和下腔静脉在3DDCEMRA的显示情况以及各种病变的3DDCEMRA表现一分析。结果3DDCEMRA显示门静脉右支级数优于2DDCEMRA（P＜0.05），且层厚越薄，显示分支越细（p＜0.01）。3DDCEMRA能较好地显示门脉主干（显示率93％）、左右分支（88％．97％）、肝静脉（81％）和腔静脉（83％），并能显示多种疾病。结论3DDCEMRA能较好地同时显示门静脉、肝静脉和下腔静脉，在门静脉和肝脏静脉系统多种疾病的显示和诊断方面具有较高使用价值。     

3D FIESTA联合3D TOF MRA对三叉神经血管压迫的诊断价值

目的 :探讨MRI 3D循环相位稳态采集快速成像(FIESTA)序列联合3D TOF MRA序列对三叉神经血管压迫的诊断价值。方法:选取以原发性三叉神经痛就诊的患者25例,均行3D FIESTA和3D TOF MRA。由2名有经验的影像诊断医师在不知道临床症状的情况下对图像进行观察,分析2种序列中三叉神经和邻近血管的走行关系,以评价2种序列联合显示神经血管压迫与临床症状的相关性。结果:20例行手术治疗,与手术结果对照,MRI对血管压迫诊断的阳性符合率为78.9%(15/19),另4例为假阳性(21.1%,4/19);1例术前MRI诊断未见明确神经血管压迫者术中得到证实。5例术前MRI诊断无神经血管压迫的患者未行手术治疗。结论:MRI 3D FIESTA联合3D TOF MRA可清晰显示三叉神经的血管压迫情况,且与临床症状具较好相关性,可帮助临床医师进行术前评估。     

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     

肝内门静脉和肝静脉的解剖与变异(三维动态增强磁共振血管成像分析)

目的用三维动态增强磁共振血管成像（３ｄｉｍｅｎｔｉｏｎａｌｄｙｎａｍｉｃｃｏｎｔｒａｓｔｅｎｈａｎｃｅｄＭＲＡ,３ＤＤＣＥＭＲＡ）前瞻性地观测肝内门静脉（简称门脉）和肝静脉的解剖和变异。方法共进行１４２例门脉和肝静脉３ＤＤＣＥＭＲＡ检查。对肝内门脉和肝静脉的解剖和变异做分型,计算每一型所占总调查人数的比例,并计算右后下肝静脉的显示率。结果１４２次成像中,８例（５．６％）显示门脉呈三分叉状,７例（４．９％）门脉先分出右后支,然后上行分为左支和右前支,４例（２．８％）门脉右前支源于左支,未发现有门脉左支水平段或右支缺如,余下１２３例（８６．６％）显示正常门脉分支。绝大多数情况下（９５．１％）肝中、肝左静脉合并,而三大支肝静脉单独汇入下腔静脉仅占４．９％。右后下肝静脉的显示率为７．７％。结论肝内门脉变异并不少见。肝中和肝左静脉多合并后汇入下腔静脉。部分病人有较为粗大的右后下肝静脉。３ＤＤＣＥＭＲＡ能方便而清楚地显示上述血管的解剖和变异     

Breath-Hold 3D STAR MR Angiography of the Renal Arteries Using Segmented Echo Planar Imaging

Three-dimensional (3D), cardiac triggered renal MR angiograms were acquired with excellent background suppression within a single breath-hold of 18 to 30 s using signal targeting with alternating radiofrequency (STAR), a subtraction time-of-flight MR angiography technique, and a 3D scheme combining echo planar imaging (EPI) readouts and k-space segmentation. The 3D STAR sequence was evaluated on 17 healthy individuals, 3 potential renal donors, and 2 patients with suspected renovascular hypertension. An inversion tag through the aorta was applied to produce the vascular contrast. After a suitable inflow time, 16 to 64 sections were encoded. An additional presaturation pulse applied over the imaging volume prior to tagging permitted improved background suppression by reducing signal variations from involuntary motion and changes in the cardiac period during breath-holding. Intrarenal branches were observed consistently in all healthy individuals. Longer inflow times provided better depiction of the intrarenal vessels while shorter delays delineated the proximal renal branches with better signal-to-noise ratio. Breath-hold and diastolic data collection reduced both blurring and flow related dephasing. Our results demonstrate excellent visualization of the renal arteries to the level of intrarenal branch vessels using the proposed technique.     

Navigator-gated free-breathing 3D balanced FFE projection renal MRA: Comparison with contrast-enhanced breath-hold 3D MRA in a swine model.

A cardiac-triggered, free-breathing, 3D balanced FFE projection renal MR angiography (MRA) technique with a 2D pencil beam aortic labeling pulse for selective aortic spin tagging was developed. For respiratory motion artifact suppression during free breathing, a prospective real-time navigator was implemented for renal MRA. Images obtained with the new approach were compared with standard contrast-enhanced (CE) 3D breath-hold MRA in seven swine. Signal properties and vessel visualization were analyzed. With the presented technique, high-resolution, high-contrast renal projection MRA with superior vessel length visualization (including a greater visible number of distal branches of the renal arteries) compared to standard breath-hold CE-MRA was obtained. The present results warrant clinical studies in patients with renal artery disease.     

门静脉、肝静脉和下腔静脉的三维动态增强MRA:快、慢速灌注法的对比研究

目的：比较快速和慢速注射造影剂法３ＤＤＣＥＭＲＡ显示ＰＶ，ＨＶ和ＩＶＣ的差别；评价３ＤＤＣＥＭＲＡ在门静脉和肝脏静脉系统中的使用价值。材料和方法：本研究分两部分。首先行肝脏横断面动态扫描，测定快速法和慢速法注射造影剂ＰＶ、ＨＶ和ＩＶＣ达信号峰值的时间，以确定第二部份快速法和慢速法３ＤＤＣＥＭＲＡ的最佳延迟时间。然后在此基础上，我们做了４０次快速法和８０次慢速法３ＤＤＣＥＭＲＡ成像。对两种增强方式显示血管的差异进行比较，并对各种病变的３ＤＤＣＥＭＲＡ的表现做分析。结果：快速法和慢速法均能较好显示ＰＶ，显示效果相仿（ｐ＞０．０５）。慢速法显示ＨＶ和ＩＶＣ效果较好，优于快速法（分别为ｐ＜０．０１，ｐ＜０．０５）；３ＤＤＣＥＭＲＡ能较好显示多种疾病。结论：快速法和慢速法３ＤＤＣＥＭＲＡ显示ＰＶ均较满意，但后者显示ＨＶ和ＩＶＣ优于前者，对于门静脉和肝脏静脉系统多种疾病的显示和诊断具有重要价值     

Direct comparison of sensitivity encoding (SENSE) accelerated and conventional 3D contrast enhanced magnetic resonance angiography (CE‐MRA) of renal arteries: Effect of increasing spatial resolution

Purpose:

To assess the effect of attaining higher spatial resolution in contrast‐enhanced magnetic resonance angiography (MRA) of renal arteries using parallel imaging, sensitivity encoding (SENSE), by comparing the SENSE contrast‐enhanced (CE) MRA against a conventional CE‐MRA protocol with identical scan times, injection protocol, and other acquisition parameters.

Materials and Methods:

Numerical simulations and a direct comparison of SENSE‐accelerated versus conventional acquisitions were performed. A total of 41 patients (18 male) were imaged using both protocols for a direct comparison. Both protocols used fluoroscopic triggering, centric encoding, breath‐holding, equivalent injection protocol, and lasted ≈30 seconds.

Results:

Simulated point‐spread functions were narrower for the SENSE protocol compared to the conventional protocol. In the patient study, although the SENSE protocol produced images with lower signal‐to‐noise ratio (SNR), image quality was better for all segments of the renal arteries. In addition, ringing of kidney parenchyma and renal artery blurring were significantly reduced in the SENSE protocol. Finally, reader confidence improved with the SENSE protocol.

Conclusion:

Despite a reduction in SNR, the higher‐resolution SENSE CE‐MRA provided improved image quality, reduced artifacts, and increased reader confidence compared to the conventional protocol. J. Magn. Reson. Imaging 2010;31:149–159. © 2009 Wiley‐Liss, Inc.     

3D DCE-MRA在腹部血管病变中的应用

目的 探讨3D动态增强磁共振血管造影在腹部血管病变中的检查技术及临床应用。方法 搜策18例腹部血管的3DDCE—MRA检查资料，对其影像表现进行总结分析。结果 18例3DDCE—MRA血管均显示满意，表现正常者4例，动脉硬化2例，腹主动脉瘤1例，门脉高压6例，门静脉瘤栓5例，其中2例显示门静脉海绵样变性。结论 3DDCE—MR～无损伤，成像速度快，对腹部大血管的病变能清楚显示，有重要的临床应用价值。     

Low-dose 3D time-resolved magnetic resonance angiography (MRA) of the supraaortic arteries: correlation with high spatial resolution 3D contrast-enhanced MRA

Purpose

To evaluate the feasibility of low‐dose, 3D time‐resolved contrast‐enhanced magnetic resonance angiography (TR‐CEMRA) in the assessment of the supraaortic vessel, and to compare the results with high‐resolution contrast‐enhanced MRA (HR‐CEMRA).

Materials and Methods

This was an Institutional Review Board‐approved retrospective study. Forty‐five consecutive patients underwent contrast‐enhanced 3D TR‐CEMRA and 3D HR‐CEMRA for evaluation of neurovascular disease at 3.0 T. Gadobutrol was administered at a constant dose of 1 mL for TR‐CEMRA (independent of patient weight), and 0.1 mmol/kg for HR‐CEMRA. Two readers evaluated image quality using a four‐point scale (from 0 = excellent to 3 = nondiagnostic), and subsequently graded each stenosis into clinically relevant categories: normal (0%), mild stenosis (<50%), moderate to severe (>50%), and occlusion.

Results

The overall image quality for low‐dose TR‐CEMRA was in the diagnostic range (median 0, range 0–3). On the grading of stenosis, TR‐CEMRA using the TWIST sequence correlated with HR‐CEMRA (r = 0.668, P < 0.001). In terms of the comparison of TR‐CEMRA with HR‐CEMRA, of the 675 supraaortic arterial segments evaluated for stenosis or occlusion, agreement occurred in 611 of 675 (90.5%), overestimation in 41 of 675 (6.1%), and underestimation 23 of 675 (3.4%).

Conclusion

TR‐CEMRA achieved by administration of a small contrast dose (1 cc) yields rapid and important functional and anatomical information in the evaluation of supraaortic arteries. Due to limited spatial resolution, TR‐CEMRA at the current parameters has a tendency to overestimate the stenosis of smaller intracranial arteries compared to HR‐CEMRA. J. Magn. Reson. Imaging 2011;33:71–76. © 2010 Wiley‐Liss, Inc.