相位对比法MRA在颅内静脉窦病变中的应用

目的 评价相位对比法(PC)磁共振血管造影(MRA)对颅内静脉窦病变的显示能力及其应用价值.方法 累及静脉窦的病变共44例.动静脉畸形(AVM)19例,动静脉瘘(AVF)6例,静脉窦血栓形成(DST)2例,脑膜瘤16例,结核1例.其中行2DPC法MRA检查的息者共35例,3D PC法MRA检查6例,3例同时行2D PC法和3D PC法检查.9例同时行DSA检查.结果 PC法MRA对AVM供血动脉的显示不如3D TOF法,但能更好地显示引流静脉的数量、方向、受累及静脉窦的形态,瘤巢的信号也较3D TOF法高;PC法MRA能清晰显示Galen静脉型动静脉瘘(AVF)扩张的Galen静脉和引流静脉以及海绵窦动静脉瘘(CS-DAVF)时"血管湖"状扩张的海绵窦和眼上静脉、蝶顶窦、岩上窦、岩下窦等引流静脉;静脉窦血栓形成时Pc法MRA出现血流缺损和引流静脉的扩张;PC法MRA能显示镰旁和后颅窝脑膜瘤和结核灶造成的静脉窦移位、狭窄、闭塞等形态的改变.结论 结合常规MBI检查,PC法MRA能直观、清晰地显示静脉窦受病变累及时其形态特点.     

PC法MRA对颅内静脉窦解剖及变异的研究

目的:评价相位对比法(PC)磁共振血管造影(MRA)在颅内静脉窦解剖及变异中的应用价值,建立窦汇区正常的MRA形态,并探讨其临床意义。方法:搜集180例颅内静脉窦的PC法MRA图像进行回顾性分析,其中2D PC法165例,3D PC法15例。结果:上矢状窦、直窦、横窦和乙状窦显示率达100%,其余大部分静脉窦在Venc=10~20cm/s时也有较高的显示率;上矢状窦和直窦与左右横窦均有4种连接方式,窦汇区形态共可分为4大类;优势侧横窦以右侧居多;凡是应该双侧形成的静脉窦,均可以不对称发育,一侧可以发育差或完全不发育;绝大部分颅内静脉血经右侧横窦→乙状窦→颈内静脉回流。结论:PC法MRA是研究颅内静脉窦形态的有效方法,能为临床提供重要的参考信息。     

320排CT血管造影图像后处理技术在下肢深静脉血栓诊断中的应用

目的:探讨320排CT静脉造影(CTV)不同图像后处理技术对显示下肢深静脉血栓的价值。方法:回顾性分析经DSA及CTV证实为下肢深静脉血栓的患者56例,对比直接法CTV不同图像后处理方法对下肢深静脉栓子的检出率。结果:56例中,CTV结合DSA共确诊栓子128处,MPR及CPR正确显示124处(96.88%)、VR正确显示95处(74.22%)、MIP正确显示86处(67.19%),MPR及CPR对栓子诊断准确率高于其他2种后处理图像(χ~2=26.57和38.27,均P0.05),VR与MIP间差异无统计学意义(χ~2=1.53,P0.05)。结论:320排CT直接法CTV结合图像后处理技术是诊断下肢深静脉血栓的有效手段。     

直接CEMRA在诊断髂静脉阻塞中的价值

目的：评价直接ＣＥＭＲＡ在诊断髂静脉阻塞中的作用。方法：对７例髂静脉阻塞病变患者行增强磁共振血管成像检查,总结直接CEMRA对髂静脉及其侧支的显示结果。结果：CEMRA的原始图像及MIP均清楚显示髂静脉的狭窄,阻塞,7例均清晰显示侧支循环,显示左侧髂静脉全程闭塞4例,部分阻塞2例,狭窄1例。结论：直接增强磁共振血管成像对显示髂静脉阻塞性病变具有较大的临床应用价值。     

多层螺旋CT茎突测量方法的探讨

目的：探讨多层螺旋CT茎突测量方法。方法：对50例患者进行16层螺旋CT扫描,在工作站上用SSD、VR、MIP、MPR及CPR法测量茎突长度,在SSD、VR、MIP上分别使用3D工具及2D工具测量。测量茎突前倾角及内倾角分别使用SSD、VR、MIP测量。结果：使用MPR、CPR法及SSD、VR、MIP 2D及3D工具均可以测量茎突长度。VR、MIP、SSD 2D及3D工具测量结果无显著性差异,与MPR比较亦无明显差异。CPR测量值较MPR测量值大,差异显著。SSD、VR、M／P图像上可以准确测量茎突前倾角、内倾角,2D及3D工具测量结果有较大差异。结论：多层螺旋CT扫描可以准确测量茎突长度及倾斜角度,测量茎突长度MPR、SSD、VR、MIP均较准确;测量茎突倾斜角度以VR 2D工具更准确简便。VR操作简便快捷,且图像直观符合临床习惯,应成为常规应用。     

磁敏感加权成像和三维对比增强MR静脉成像对上矢状窦旁桥静脉的显示及比较

目的 比较磁敏感加权成像( SWI)和三维对比增强MR静脉成像(3D-CE MRV)技术 对上矢状窦旁桥静脉的显示能力,为神经外科手术的术前影像学检查提供依据.方法 20例(40侧)健康成人受检者分别行矢状面3D-CE MRV和横轴面SWI检查.3D-CE MRV的原始图像行MIP,SWI原始图像行MinIP及MPR处...     

64层CT正常颅内静脉成像

目的观察横窦和小脑幕侧窦的常见形态、变异及其临床意义．比较最大密度投影（MIP）和容积再现（VR）对颅内静脉（窦）结构的显示率。资料与方法25例CT脑静脉成像（CTV）．分别观察VR、MIP对13个颅内静脉（窦）的显示情况。结果25例总共显示494个结构。VR显示481个,MIP显示431个,经X^2检验差异有统计学意义（P〈0．001）。上矢状窦、直窦、窦汇、大脑大静脉、海绵窦、大脑内静脉和下矢状窦在VR、MIP两种重组方法中显示率均为100％。大脑中浅静脉、岩下窦、Labbe静脉、Trolard静脉VR优于MIP。小脑幕侧窦两者未见显著性差异。左侧横窦优势型4例,右侧横窦优势型11例,其中横窦发育不良2例,10例为中间型。小脑幕侧窦可分三型。结论CTV可较完整地显示颅内静脉及静脉窦,显示颅内静脉（窦）VR优于MIP;正确认识横窦、小脑幕侧窦的形态有重要的临床意义。     

动态3D CE-MRV在颅内疾病诊断及治疗中的应用初探

目的：探讨动态3D CE-MRV在颅内静脉系统疾病诊断中的成像优势及其对颅内疾病临床诊断及治疗的指导意义.方法：可疑或确诊为颅内静脉病变者36例应用3T磁共振仪及3D TRICK技术行动态CE-MRV检查,9例无颅内静脉病变者同时行2D TOF序列MRV检查.分析动态3D CE-MRV图像,观察颅内深浅静脉系统主干及其分支的显示情况,比较其相对于2D TOF序列MRV的优势;分析动态3D CE-MRV对颅内疾病如静脉窦及静脉血栓、累及静脉的血管畸形、肿瘤和外伤等的诊断价值及其对临床治疗的指导意义.结果：与2D TOF序列比较,3D CE-MRV对静脉窦属支、上下吻合静脉及海绵窦等显示更清晰（P〈0.05）.动态CE-MRV显示36例受检者大致可分为4种结果：①正常者16例,含静脉发育变异6例;②累及静脉的颅内血管畸形3例;③静脉窦或静脉血栓11例,其中3例为溶栓术后复查显示再通;④肿瘤及外伤6例：脑膜瘤或颈静脉球瘤压迫或侵犯静脉窦者3例;外伤致颅内静脉异常者3例,其中1例为颈内动脉海绵窭瘘.结论：动态3D CEMRV对颅内静脉尤其是细小静脉的观察明显优于2D TOF序列的MRV;多时相显影和多方位重组可对颅内静脉变异、静脉畸形和累及静脉的疾患能清晰显示,为临床诊断、治疗方案的确定及疗效评价提供重要的影像依据.     

脑静脉窦血栓磁共振血流成像的诊断价值

目的：探讨脑静脉磁共振血流成像在诊断脑静脉窦血栓中的应用价值。材料与方法：１２例脑静脉窦患者均作ＭＲＩ和脑静脉窦ＭＲＡ检查（３例治疗后随诊），８例行静脉期脑血管造影；与常规ＳＥ图像和Ｘ线脑血管造影对照，着重分析脑静脉ＭＲＡ在本病中的诊断价值。结果：受累的静脉窦有上矢状窦６例，窦汇（部分）８例，横窦８例（１０个），乙状窦８例（９个），直窦６例，大脑大静脉３例和大脑内静脉３例（６个）；脑静脉窦血栓ＭＲＡ直接征象为发育正常的静脉窦高血流信号缺失或再通形成的边缘模糊且不规则的较低血流信号，间接征象有病变以远静脉侧支形成或其他途径引流静脉异常扩张。结论：脑静脉窦ＭＲＡ及其原始图像在脑静脉窦血栓诊断及随诊中有独特价值，它比常规ＳＥ图像能提供更多的诊断信息，可直接显示静脉窦血栓，易于治疗后反复随诊，这些是血管造影所不及的。     

脑血管病变115例CT血管成像分析

目的：探讨64层螺旋CT脑血管成像（MSCTA）对脑血管病变的诊断价值。方法：经64层螺旋CT脑血管成像检查的病例,使用减影方法进行后处理,得到VR、MIP图像,原始图像重建得到MPR、CPR图像,综合四种图像诊断脑血管病变,并与DSA诊断进行对照分析。结果：115例脑血管病变中,动脉瘤62例（53.91%）、动静脉畸形（AVM）6例（5.21%）、脑静脉畸形（CVM）3例（2.61%）,脑动脉狭窄或闭塞38例（33.04%）、烟雾病3例（2.61%）、海绵窦动静脉瘘2例（1.74%）、海绵状血管瘤1例（0.87%）。其中46例DSA检查结果均与MSCTA一致。结论：64层螺旋CT脑血管成像是一种安全、快速、无创的检查方法,可作为颅内血管性病变筛查和术前评估的首选检查技术。     

Utility of contrast-enhanced 3D turbo-flash MR angiography in evaluating the intracranial venous system

The objective of this study was to compare the effectiveness of contrast-enhanced 3D turbo-flash and 2D time-of-flight (TOF) magnetic resonance angiography (MRA) sequences in the visualization and evaluation of the intracranial venous system. A prospective study was carried out on 41 patients referred to our Magnetic Resonance Imaging (MRI) unit with clinical findings suggestive of dural sinus thrombosis. Contrast-enhanced 3D turbo-flash and 2D TOF MRA sequences were performed, and the dural sinuses and cerebral veins were classified into five grades according to the quality of visualization and presence of thrombosis. We found the dural sinuses and cerebral veins to be normal in all sequences in 31 patients. Thrombosis of dural sinuses was detected in ten patients, with four of these ten cases found only in the contrast-enhanced 3D turbo-flash sequence. In general, complete visualization of cerebral veins and dural sinuses was significantly better accomplished with contrast-enhanced 3D turbo-flash MRA than with 2D TOF in either coronal or sagittal/oblique planes. Although 2D TOF MRA may be superior in detecting chronic dural sinus thrombosis, contrast-enhanced 3D turbo-flash MRA sequences may offer advantages for the early diagnosis and management of acute and subacute dural sinus thrombosis.     

Retrograde flow in the dural sinuses detected by three-dimensional time-of-flight MR angiography

Introduction Retrograde flow in the left dural sinuses is sometimes detected by three-dimensional time-of-flight (3D-TOF) magnetic resonance (MR) angiography. The purpose of this study was to evaluate the incidence of this phenomenon and its characteristic features on 3D-TOF MR angiograms. Methods We retrospectively reviewed cranial MR angiography images of 1,078 patients examined at our institution. All images were obtained by the 3D-TOF technique with one of two 1.5-T scanners. Maximum intensity projection (MIP) images in the horizontal rotation view were displayed stereoscopically. We reviewed the source images, inferosuperior MIP images, and horizontal MIP images and identified retrograde flow in the dural sinuses. Results We found retrograde flow in the dural sinuses of 67 patients on the source images from 3D-TOF MR angiography; the incidence was 6.2%. In 47 of the 67 patients, retrograde flow was identified in the left inferior petrosal sinus, in 13, it was seen in the left sigmoid sinus, and in 6, it was seen in the left inferior petrosal and left sigmoid sinuses. The remaining patient had retrograde flow in the left inferior petrosal and left and right sigmoid sinuses. The mean age of the patients with retrograde flow was slightly greater than that of the patients without this phenomenon (70 years vs 63 years). Conclusion Retrograde flow in the dural sinuses frequently occurs on the left side in middle-aged and elderly patients during 3D-TOF MR angiography performed with the patient in the supine position. This phenomenon should not be misdiagnosed as a dural arteriovenous fistula. This article was presented as an electronic poster paper at the 31st Congress of the ESNR held in Geneva in September 2006.     

颅内小动脉瘤高分辨率MRA

目的:评价颅内小动脉瘤的高分辨率MRA。方法:16例经DSA和/或手术证实的颅内动脉瘤(直径≤10m m )接受3D-TOFMRA检查,MRA平面内分辨率为0.39 mm ×0.78m m ,结合最佳倾斜非饱和激励(TONE)及磁化传递对比(MTC)技术,MIP重建,并对感兴趣区局部重建。结果:16例动脉瘤均为单发,呈囊状,大小3～10 m m ,其中15例经MRA作出正确诊断,敏感性为93.8% 。结论:高分辨率3D- TOFMRA非常适合颅内小动脉瘤的诊断及评价     

Non-contrast enhanced MR venography using 3D fresh blood imaging (FBI): initial experience.

OBJECTIVE: This study examined the efficacy of 3D-fresh blood imaging (FBI) in patients with venous disease in the iliac region to lower extremity. MATERIALS AND METHODS: Fourteen patients with venous disease were examined [8 deep venous thrombosis (DVT) and 6 varix] by 3D-FBI and 2D-TOF MRA. All FBI images and 2D-TOF images were evaluated in terms of visualization of the disease and compared with conventional X-ray venography (CV). RESULTS: The total scan time of 3D-FBI ranged from 3 min 24 sec to 4 min 52 sec. 3D-FBI was positive in all 23 anatomical levels in which DVT was diagnosed by CV (100% sensitivity) as well as 2D-TOF. The delineation of collateral veins was superior or equal to that of 2D-TOF. 3D-FBI allowed depiction of varices in five of six cases; however, in one case, the evaluation was limited because the separation of arteries from veins was difficult. CONCLUSION: The 3D-FBI technique, which allows iliac to peripheral MR venography without contrast medium within a short acquisition time, is considered clinically useful.     

3D DCE MRA肾静脉成像及其临床应用价值

目的:探讨三维对比增强磁共振血管成像(3D DCE MRA)行肾静脉成像及其诊断肾静脉病变的价值。材料和方法:肾静脉病变、解剖变异患者29例,常规腹部MR扫描(包括横断面T1WI、T2WI,冠状面T2WI),三维容积超快速多期动态增强扫描序列(Propeller LAVA)行冠状面血管成像,采用容积再现(VR)、多平面重建(MPR)及最大强度投影(MIP)进行肾静脉重建。结果:肾癌肾静脉瘤栓5例,表现为条状或结节状充盈缺损;门静脉高压肾静脉侧支循环10例:与脾静脉交通7例,与胃底曲张静脉团交通1例,门脉高压脾-肾静脉交通并左侧性腺静脉曲张2例;左肾静脉压迫综合征2例,其中1例与腰静脉丛交通;性腺静脉曲张14例,右侧2例,左侧13例,其中肝癌下腔静脉阻塞综合征并双侧性腺静脉扩张1例,曲张的性腺静脉与左肾内静脉分支相连2例;解剖变异1例。结论:3DDCEMRA能清楚显示肾静脉及其病变,能为肾静脉相关疾病的诊断及制定手术方案提供依据。     

Evaluation of the intracranial dural sinuses with a 3D contrast-enhanced MP-RAGE sequence: prospective comparison with 2D-TOF MR venography and digital subtraction angiography

BACKGROUND AND PURPOSE: The diagnosis of dural sinus thrombosis is often difficult because of its variable and nonspecific clinical presentation and the overlapping signal intensities of thrombosis and venous flow on conventional MR images and MR venograms. We compared 3D contrast-enhanced magnetization-prepared rapid gradient-echo (MP-RAGE) sequences with 2D time-of-flight (TOF) MR venography, digital subtraction angiography (DSA), and conventional spin-echo (SE) MR imaging for the assessment of normal and abnormal dural sinuses. METHODS: In a phantom study, a plastic tube with pulsating flow was used to simulate the intracranial dural sinus. With 3D MP-RAGE, a variety of flow velocities, contrast material concentrations, and angulations between the phantom flow tube and the plane of acquisition were tested to measure their relationship to signal-to-noise ratio (SNR). In a clinical study, 35 patients, including 18 with suspected dural sinus thrombosis, were studied with both MR imaging and DSA. Receiver operating characteristic (ROC) analysis was performed in a blinded fashion using DSA as the reference standard. RESULTS: With the phantom, the SNR of flow increased with increasing contrast concentration, but was not affected by the angle between the tube and scan slab. There was no relationship between SNR and velocity when the contrast concentration was 1.0 mmol/L or greater. In the clinical study, dural sinus thrombosis as well as the normal anatomy of the dural sinuses were seen better with 3D contrast-enhanced MP-RAGE than with 2D-TOF MR venography. Three-dimensional contrast-enhanced MP-RAGE showed the highest diagnostic confidence on ROC curves in the diagnosis of thrombosis. CONCLUSION: Three-dimensional contrast-enhanced MP-RAGE is superior to 2D-TOF MR venography and conventional SE MR imaging in the depiction of normal venous structures and the diagnosis of dural sinus thrombosis, and is a potential alternative to DSA.     

主动脉夹层：3D DCE MRA诊断

探讨３Ｄ ＤＣＥ ＭＲＡ对主动脉夹层诊断的价值及其检查技术。材料和方法：共作主动脉夹层２８例３Ｄ ＤＣＥ ＭＲＡ检查。采用３Ｄ ＦＳＧＲ,团注Ｇｄ－ＤＴＰＡ ２０ｍｌ,屏气扫描时间１６－２２秒。经工作站进行了ＭＩＰ和ＭＰＲ重建。结果：分析２８例主动脉夹层３Ｄ ＤＣＴ ＭＲＡ表现,发现３Ｄ ＤＣＥ ＭＲＡ为主动脉夹层的上下范围,内膜片,破口,真两腔以及分支受累情况均能满意显示。     

磁共振脑静脉系血管成像技术及其临床应用

目的探讨磁共振脑静脉系血管成像的技术方法和最佳扫描方案，评价磁共振静脉系血管成像技术(MR venography，MRV)对静脉系疾病的诊断价值及临床意义。方法采用二维时间飞跃法MR血管造影(2D-TOF-MRA)、二维相位对比血管造影(2D-PCA)和三维对比增强MR血管造影(3D-CE-MRA)3种血管成像技术分别对20例健康志愿者和20例临床或MRI疑有静脉系疾病的患者行MRV成像，并采用最大强度投影(MIP)、多平面或曲面重建(MPR)及数字减影MRA(DSMRA)技术对图像进行后处理，观察脑静脉系在MRV中的显示情况及脑静脉系疾病在MRV中表现形式，制定脑静脉系成像的最佳方案。结果本组经3D-CE-MRA静脉系成像诊断为13例颅内静脉窦血栓形成(CVST)及7例颅内肿瘤累及静脉系的阳性显示率为100％，均经临床治疗复诊及手术证实。2D-PCA及2D-TOF-MRA对细小引流静脉显示欠佳，且2D-TOF-MRA对复杂区域内静脉血管亦显示欠佳。结论3D-CE-MRA结合2D-PCA及2D-TOF-MRA静脉成像技术形成全脑静脉系成像，为脑静脉系的最佳成像方案，对临床术前评估和指导治疗有极其重要的意义。     

Contrast-Enhanced Time-Resolved MRA for Follow-Up of Intracranial Aneurysms Treated with the Pipeline Embolization Device

BACKGROUND AND PURPOSE:Endovascular reconstruction and flow diversion by using the Pipeline Embolization Device is an effective treatment for complex cerebral aneurysms. Accurate noninvasive alternatives to DSA for follow-up after Pipeline Embolization Device treatment are desirable. This study evaluated the accuracy of contrast-enhanced time-resolved MRA for this purpose, hypothesizing that contrast-enhanced time-resolved MRA will be comparable with DSA and superior to 3D-TOF MRA.MATERIALS AND METHODS:During a 24-month period, 37 Pipeline Embolization Device–treated intracranial aneurysms in 26 patients underwent initial follow-up by using 3D-TOF MRA, contrast-enhanced time-resolved MRA, and DSA. MRA was performed on a 1.5T unit by using 3D-TOF and time-resolved imaging of contrast kinetics. All patients underwent DSA a median of 0 days (range, 0–68) after MRA. Studies were evaluated for aneurysm occlusion, quality of visualization of the reconstructed artery, and measurable luminal diameter of the Pipeline Embolization Device, with DSA used as the reference standard.RESULTS:The sensitivity, specificity, and positive and negative predictive values of contrast-enhanced time-resolved MRA relative to DSA for posttreatment aneurysm occlusion were 96%, 85%, 92%, and 92%. Contrast-enhanced time-resolved MRA demonstrated superior quality of visualization (P = .0001) and a higher measurable luminal diameter (P = .0001) of the reconstructed artery compared with 3D-TOF MRA but no significant difference compared with DSA. Contrast-enhanced time-resolved MRA underestimated the luminal diameter of the reconstructed artery by 0.965 ± 0.497 mm (27% ± 13%) relative to DSA.CONCLUSIONS:Contrast-enhanced time-resolved MRA is a reliable noninvasive method for monitoring intracranial aneurysms following flow diversion and vessel reconstruction by using the Pipeline Embolization Device.

Surgical clipping or endovascular coil embolization is generally the preferred treatment for intracranial aneurysms.¹ The Pipeline Embolization Device (PED; Covidien, Irvine, California) is an endovascular device that has redefined the scope of treatment for large, giant, wide-neck, or fusiform aneurysms or aneurysms having failed coil embolization, by reconstructing the parent artery and restoring its natural course.² The PED is designed for 85% reduction of blood flow within an aneurysm, which induces thrombosis² while keeping perforators and/or side branch vessels patent.³ Results from a multicenter prospective trial for treatment of uncoilable or failed large and giant ICA aneurysms with the PED demonstrated 99% technical success and 74% complete occlusion with 6% major ipsilateral stroke or death.⁴ Flow diversion with the PED has also been reported in the treatment of HIV vasculopathy, with fusiform cerebral aneurysms precluding parent vessel sacrifice or surgical bypass.⁵Digital subtraction angiography is the reference standard for the evaluation of aneurysms after endovascular treatment due to its unsurpassed spatial resolution; however, DSA is invasive and not without risks of puncture site and neurologic complications.⁶ Posttreatment follow-up of intracranial aneurysms after coil embolization with MRA by using 3D-TOF or contrast-enhanced techniques is a potential noninvasive alternative to DSA for the evaluation of PED-treated aneurysms without the use of ionizing radiation.⁷ Contrast-enhanced time-resolved MRA (CE-TR MRA) uses acquisition schemes aimed at accelerated data collection, primarily using parallel imaging algorithms and novel k-space trajectories to achieve high temporal resolution for multiphasic MRA examinations. This technique provides consistent, technologist-independent, optimal arterial enhancement for contrast-enhanced MRA and provides information on temporal contrast kinetics.^8,9 Use of CE-TR MRA has been reported in the evaluation of intracranial lesions such as arteriovenous malformations and dural arteriovenous fistulas and for assessment of stenosis of the extracranial carotid artery, and it seems to be a promising technique for evaluating aneurysms after stent-assisted coil embolization.^9–11We hypothesized that TR-CE MRA could provide information comparable with DSA and would be superior to 3D-TOF MRA in the evaluation of intracranial aneurysms and the parent artery following flow diversion and parent vessel reconstruction with the PED.