MRI评价肺动静脉瘘

目的　评价MRI、MRA等对肺部血管畸形的临床应用价值。方法　分析了 6例手术或血管造影证实的AVF病例的多种表现 ,其中男 5例 ,女 1例 ,采用 1.0T超导MRI仪 ,体线圈技术。分别行SE、2D TOF、3D TOF及cine MRI多种序列成像 ,共行 3 5次MRI和MRA等检查。结果　 6例AVF中共发现 9个病灶。 2例共 3个病灶在SE序列中可见大小不等流空信号 ,其余为等信号之软组织块影、边缘不规则 ;在梯度回波序列 (2D、3D TOF及cine MRI)中病灶均呈高信号或极高信号影 ,在2D TOF中可见到 5例病灶的供血动脉及 3例引流静脉 ;在 3D TOF中可见到 4例病灶的供血动脉及 2例引流静脉 ;在cine MRI序列中可见到 3例病灶供血动脉及 2例引流静脉 ,且cine MRI可见到 5例病灶内信号强弱变化同心动周期一致。结论　目前 ,MRI多种序列的结合应用 ,可以较准确地诊断AVF ,作为一种无创性诊断方法有一定临床应用价值。     

20例成人烟雾病DSA、MRA与TCD特征分析

<正>选择我科2007年3月～2010年4月收治的成人烟雾病患者20例,男16例,女4例;年龄42～65岁;首发症状为TIA4例,急性脑梗死8例,脑出血3例(其中基底核同一部位2次出血者1例),蛛网膜下腔出血1例,长期慢性头昏3例,慢性头痛1例;既往体健8例,原发性高血压病7例,糖尿病1     

椎动脉发育不良的M RA 分型及临床意义

目的：研究椎动脉发育不良的磁共振血管造影分型及临床意义。方法对80例椎动脉发育不良患者的磁共振血管造影检查结果进行分型,分析不同分型与后循环短暂性脑缺血发作及脑梗死的相关性。结果椎动脉发育不良根据磁共振血管造影表现分为Ⅳ型,其中Ⅰ型后循环短暂性脑缺血发作发生率为81．8％、脑梗死发生率为9．1％,Ⅱ型分别为75．0％、17．9％,Ⅲ型分别为62．5％、29．2％,Ⅳ型分别为35．3％、58．8％;不同分型患者后循环短暂性脑缺血发作及脑梗死的发生率比较差异有显著或极显著性（χ2＝33．57、11．21,P＜0．05或0．01）。结论根据磁共振血管造影影像学表现,可将椎动脉发育不良分为Ⅳ型;椎动脉发育不良分型越高,发生脑梗死的概率越高。     

三种TOF法MRA诊断实验性动脉瘤的对比分析

目的：比较分析三种ＴＯＦ法ＭＲＡ的图像质量，以及不同成像技术对动脉瘤的诊断价值。材料与方法：用静脉囊镶嵌法将１８只犬制成三种类型（单侧型、分叉型、末梢型）颈总动脉囊状动脉瘤模型，术后２周分别进行ＩＡＤＳＡ、２ＤＴＯＦ、单层块３ＤＴＯＦ、薄块多层重叠技术（ＭＯＴＳＡ）ＭＲＡ检查。结果：以ＩＡＤＳＡ图像为标准，２ＤＴＯＦ、单层块３ＤＴＯＦ、ＭＯＴＳＡＭＲＡ都能显示动脉瘤的位置、形态、类型、大小、瘤颈、瘤体伸展方向。其中以ＭＯＴＳＡＭＲＡ图像最具评价能力，显示动脉瘤的形态、类型、瘤颈优于２ＤＴＯＦ、单层块３ＤＴＯＦ，不足之处图像有层块梯阶样伪影。三种ＴＯＦ成像技术对动脉瘤内缓慢血流、湍流、血栓、大动脉瘤有不同程度的信号丢失。结论：三种ＴＯＦ法成像技术中，ＭＯＴＳＡ技术最有利于作为临床３ＤＴＯＦ法ＭＲＡ检查颅内动脉瘤的常规成像技术。     

颈动脉三维增强磁共振血管成像技术初步探讨

目的　探讨颈动脉三维增强磁共振血管成像 (3DCEMRA)方法和影响图像质量的因素。方法　使用 1.5T超导型MR扫描机 ,头部、颈部以及部分腰椎相控阵线圈。对 48例病人进行颈动脉 3DCEMRA增强扫描。检查时 ,嘱患者屏气 ,于静脉内团注钆双胺 (Gd -DTPA -BMA)对比剂后进行颈动脉期扫描 ,用 3DFLASH序列采集图像。结果　检查的病例 96%获得了满意的图像 ,经MIP和MPR重建后 ,能够清楚显示颈动脉正常解剖结构和病变的部位、大小及其狭窄程度。 2 3例经数字减影血管造影(DSA)或 /和超声以及手术证实的病例中 ,3DCEMRA显示颈动脉的特异性和敏感性均为 10 0 %。结论　高质量的颈动脉MRA图像依赖于注药后扫描时机的准确性 ,注药流速与总量的合理性 ,合适的扫描序列 ,以及操作者的技巧和熟练程度     

"Soap-Bubble" visualization and quantitative analysis of 3D coronary magnetic resonance angiograms.

In order to compare coronary magnetic resonance angiography (MRA) data obtained with different scanning methodologies, adequate visualization and presentation of the coronary MRA data need to be ensured. Furthermore, an objective quantitative comparison between images acquired with different scanning methods is desirable. To address this need, a software tool ("Soap-Bubble") that facilitates visualization and quantitative comparison of 3D volume targeted coronary MRA data was developed. In the present implementation, the user interactively specifies a curved subvolume (enclosed in the 3D coronary MRA data set) that closely encompasses the coronary arterial segments. With a 3D Delaunay triangulation and a parallel projection, this enables the simultaneous display of multiple coronary segments in one 2D representation. For objective quantitative analysis, frequently explored quantitative parameters such as signal-to-noise ratio (SNR); contrast-to-noise ratio (CNR); and vessel length, sharpness, and diameter can be assessed. The present tool supports visualization and objective, quantitative comparisons of coronary MRA data obtained with different scanning methods. The first results obtained in healthy adults and in patients with coronary artery disease are presented.     

Lower extremities magnetic resonance angiography with blood pressure cuff compression: Quantitative dynamic analysis

Purpose

To quantitatively evaluate changes induced by the application of a femoral blood‐pressure cuff (BPC) on run‐off magnetic resonance angiography (MRA), which is a method generally previously proposed to reduce venous contamination in the leg.

Materials and Methods

This study was Health Insurance Portability and Accountability Act (HIPAA)‐ and Institutional Review Board (IRB)‐compliant. We used time‐resolved gradient‐echo gadolinium (Gd)‐enhanced MRA to measure BPC effects on arterial, venous, and soft‐tissue enhancement. Seven healthy volunteers (six men) were studied with the BPC applied at the mid‐femoral level unilaterally using a 1.5T MR system after intravenous injection of Gd‐BOPTA. Different statistical tools were used such as the Wilcoxon signed rank test and a cubic smoothing spline fit.

Results

We found that BPC application induces delayed venous filling (as previously described), but also induces significant decreases in arterial inflow, arterial enhancement, vascular‐soft tissue contrast, and delayed peak enhancement (which have not been previously measured).

Conclusion

The potential benefits from using a BPC for run‐off MRA must be balanced against the potential pitfalls, elucidated by our findings. J. Magn. Reson. Imaging 2009;29:1450–1456. © 2009 Wiley‐Liss, Inc.     

PWI联合MRA评价侧支循环在后循环远端缺血中的代偿作用

目的 探讨磁共振灌注加权成像(PWI)联合磁共振血管造影(MRA)评价侧支循环在后循环远端缺血中的代偿作用.方法 搜集32例伴有椎基底动脉重度狭窄的后循环缺血患者(病例组),分析PWI和MRA检查资料,并与30名健康志愿者(对照组)比较,观察后循环血管狭窄程度,侧支血管的显示,局部脑血流量(rCBF)、局部脑血容量(rCBV)、平均通过时间(rMTT)指标.结果 病例组中后交通动脉开放22例;软脑膜动脉显示11例;微小动脉团显示12例.病例组ROL/额叶白质比值相对于对照组rCBF、rCBV值均下降,MTT值延长,两组参数比较P值均＜0.05,有统计学差异.病例组中有后交通开放的患者与未开放的患者比较,rCBF升高,MTT缩短,P值均＜0.05;而rCBV两组间比较,P值=0.36(＞0.05),无统计学差异.结论 PWI联合MRA可以客观地评价后交通动脉在后循环远端缺血中的代偿作用,为临床治疗及判断预后提供帮助.     

烟雾病8例临床分析

目的 探讨烟雾病的临床特征、影像学诊断价值及治疗。方法 回顾性分析8倒烟雾病患者的临床特征和辅助检查结果及治疗。结果 本组成人（5例）多于儿童（3例）;儿童临床表现以脑缺血症状为主;脑磁共振血管成像（MRA）或数字减影血管造影（DSA）检查显示颈内动脉虹吸部末端和大脑前或中动脉近端狭窄或闭塞,并有脑基底部异常血管网形成。内科保守治疗5倒。合并手术治疗3倒,进行0．5—5．0年随访,1例遗留轻度神经系统异常后遗症。结论烟雾病儿童主要表现为脑缺血症状;脑MRA或DSA的异常征象是早期诊断烟雾病的重要依据。早期诊断、及时治疗是改善烟雾病预后的有效方法。