下肢深静脉血栓形成MR直接成像的临床应用

目的 探讨下肢深静脉血栓形成磁共振直接成像(magnetic resonance direct thrombus imaging,MRDTI)的临床应用价值.方法 对31例临床确诊下肢深静脉血栓形成的患者进行了MRDTI和MRA检查,MRDTI选用SE序列TlWI、FSE序列T2W1、FAST(fourier acquired steady state)序列.其中23例患者做了数字减影血管造影(digital subtraction angiography,DSA)检查.结果 急性血栓共23例,血栓在FSE序列T2WI、FAST多为等、高信号表现,信号多不均匀.慢性血栓共8例:血栓在FSE序列T2WI、SE序列T1WI、FAST多为低信号或等信号,3 例慢性血栓形成有血管壁增厚、血管壁不规则表现.下肢深静脉血栓形成的MRA表现有:静脉充盈缺损(19例)、静脉闭塞和中断(9例)、静脉再通(4例)、侧枝循环形成(31例).以DSA为诊断标准,MRA诊断符合率为95.65%.结论 对下肢深静脉血栓形成MRDTI检查町作为MRA检查的重要补充.     

MR血管成像在诊断下肢深静脉血栓形成中的价值并与DSA对照研究

目的探讨下肢深静脉血栓形成MR血管成像（MRA）的临床价值。方法对30例怀疑下肢深静脉血栓形成的患者进行了MRA和DSA检查，MRA采用二维时间飞越法（2DTOF）。对MRA与DSA表现进行对照分析。结果下肢深静脉血栓形成的MRA表现有1静脉充盈缺损（14例）、静脉闭塞和中断（8例）、静脉再通（3例）、侧支循环形成（25例）。以DSA为标准，MRA诊断出所有病变，但有1例假阳性。结论MRA作为无创性检查，是诊断下肢深静脉血栓有效的检查方法之一。     

脑静脉窦血栓形成的磁共振成像诊断

目的　探讨磁共振成像 (MRI)和磁共振血管成像 (MRA)对脑静脉窦血栓形成的诊断价值。方法　 2 0例脑静脉窦血栓形成中 ,男 8例 ,女 12例。年龄 9～ 5 4岁 ,平均 3 5岁。全部有MRISE序列平扫 ,10例有TOF法静脉MRA ,3例有MRIGd -DTPA增强 ;13例有平扫CT对照。急性期 ( <1周 )脑静脉窦血栓形成 3例 ;亚急性期 ( 1～ 2周 ) 13例 ;慢性期 ( >2周 ) 4例。结果　 2 0例脑静脉窦血栓形成中 ,MRISE序列扫描确诊 19例 ,1例急性期早期MRI平扫漏诊 ,后经MRA确定。 13例CT平扫均未能确定脑静脉窦血栓的诊断。急性期脑静脉窦血栓MRI信号复杂 ,T1WI呈低、中等或稍高信号 ,T2 WI呈明显低信号。亚急性期呈短T1和长T2 信号 ,表现典型 ;慢性期由高信号到低信号 ,最后血栓吸收 ,静脉窦再通。MRA表现为静脉窦闭塞或静脉窦内充盈缺损。结论　MRI和MRA是诊断和随诊静脉窦血栓形成的有效手段 ,对脑静脉窦血栓的诊断优于CT ,可替代有创伤性的DSA检查     

MRA在诊断外周血管疾病中的价值:与DSA对照研究

目的探讨磁共振血管造影（MRA）在诊断外周血管疾病中的价值。资料与方法怀疑外周血管疾病患者38例,分别行MRA和DSA检查,对血管显示情况进行比较。结果38例患者中MRA显示静脉病变24例,其中下肢深静脉血栓形成13例,下肢静脉曲张8例,髂静脉受压综合征2例,Klippel—Trenaunay综合征1例;动脉病变14例,其中闭塞性脉管炎9例,下肢动脉粥样硬化4例,动脉急性栓塞1例。MRA结果与DSA一致。结论MRA作为一种无创性检查,是诊断外周血管疾病的有效检查方法之一。     

磁敏感加权成像在脑部疾病中的研究

目的探讨磁敏感加权成像（SWI）序列在诊断脑部疾病中的临床应用价值。方法回顾性分析45例经临床随访、数字减影血管造影（DSA）或手术病理证实的脑部疾病患者的磁共振成像（MRI）资料。MRI检查包括T1WI、T2WI、T2-磁共振成像液体衰减反转恢复序列（FLAIR）、SWI。分析各种疾病的影像学表现,评价SWI在诊断脑部疾病中的优劣。结果海绵状血管瘤19例,SWI检出19例,检出率100%;T1WI序列检出8例,检出率42%。动静脉畸形出血12例,SWI序列、T2-FLAIR及T2WI序列检出12例,检出率均为100%,T1WI序列检出10例,检出率83%,SWI与其他序列对比无明显差别。静脉窦血栓检出3例,SWI除检出静脉窦血栓外,还可以显示周围引流静脉。急性脑梗死6例,其中3例SWI显示有出血,常规T1WI检查序列仅1例显示。脑肿瘤5例,其中3例SWI较T1WI、T2WI更好地显示其内出血和周围引流静脉。结论SWI能够清晰显示血流缓慢的静脉血管及微小出血灶,在显示病灶的内部结构方面也有独特的优势,能发现常规MRI不能显示的信息。     

脑静脉窦血栓的磁共振表现及误漏诊分析

目的总结脑静脉窦血栓（CVST）的磁共振表现,并进行误漏诊分析. 资料与方法回顾性分析32例脑静脉窦血栓的磁共振表现.全部病例均进行MRI检查,其中17例同时行磁共振静脉成像（MRV）检查,12例行增强扫描,29例行CT检查.全部病例经DSA证实. 结果 32例CVST患者中,MRI SE序列扫描确诊26例,其中亚急性期病变20例,急性期4例,慢性期2例.6例急性期病变MRI平扫漏诊,其中4例经MRV确诊,2例经DSA诊断.急性期CVST MRI信号复杂,T1WI呈低、中等或稍高信号,T2WI呈明显低信号.亚急性期T1WI和T2WI均呈高信号,表现典型;慢性期血栓信号不断地降低.MRV表现为静脉窦闭塞或静脉窦内充盈缺损.本组病例中有7例曾被误诊为肿瘤、脑梗死等其他病变. 结论 MRI和MRV是诊断CVST的良好检查方法,可提供更多可靠信息.应用适当的检查技术,以及对MR征象进行认真分析,可避免误诊及漏诊.     

3．0TM砒与MR静脉成像诊断脑静脉窦血栓形成的价值

目的探讨3．0T MRI与MR静脉成像（MRV）对脑静脉窦血栓形成的诊断价值。方法回顾性分析10例经DSA确诊的脑静脉窦血栓形成患者的临床及MRI资料。结果10例患者在常规MRI检查上均有不同脑区的皮质、皮质下脑组织静脉性脑梗死的MRI表现，8例伴明显脑肿胀；7例患者的静脉窦内有异常信号，其中6例MRI表现为静脉窦内T1WI、T2WI高信号，1例T1WI高及稍高信号、T2WI低信号。9例MRV检查均发现静脉窦充盈缺损或中断。结论3．0T MRI结合MRV是诊断和随访静脉窦血栓形成的有效手段，可替代创伤性的DSA检查。     

MRI联合磁共振静脉成像诊断脑静脉窦血栓形成的价值

目的:探讨MRI及磁共振静脉成像(MRV)对脑静脉窦血栓形成的诊断价值.方法:回顾性分析37例DSA确诊脑静脉窦血栓形成患者的临床资料及影像表现.37例中有30例行常规MRI检查,29例行MRV(2D TOF)检查.结果:30例常规MRI检查中28例静脉窦有异常信号,其中26例MRI表现为静脉窦T1WI、T2WI高信号,2例T1WI等信号、T2WI低信号,并部分伴有脑组织梗死、出血.29例MRV检查均发现静脉窦充盈缺损或中断.结论:MRI与MRV结合对诊断脑静脉窦血栓形成具有高度敏感性,是诊断静脉窦血栓形成的首选检查方法.     

常规MRI联合MR脑血管成像在围产期脑后部可逆性脑病综合征中的应用研究

目的：探讨常规磁共振成像（MRI）联合MR脑血管成像在围产期脑后部可逆性脑病综合征（PRES）诊断和鉴别诊断中的应用价值。方法：5例围产期PRES患者,平均年龄为26.5岁,且均于起病后2 d内行常规MRI和MR脑血管成像,MR脑血管成像包括MR脑动脉成像（MRA）和MR脑静脉成像（MRV）。结果：病变均累及双侧顶枕叶,另累及额叶2例,基底节区2例,桥脑1例,病变占位效应不明显。病变主要位于皮层下白质,其中1例累及皮质。病变T1WI呈低、等信号,T2WI及液体衰减反转恢复序列（FLAIR）呈高信号。3例磁共振扩散加权成像（DWI）呈等信号,表观扩散系数（ADC）图为高信号,另2例部分病变DWI为高或稍高信号。增强扫描以上病变未见明确强化,MRA、MRV未见明确异常。结论：围产期RPES的MRI表现较具特征性,常规MRI联合MR脑血管成像有助于本病的早期诊断和鉴别诊断。     

MRI常规扫描序列与EPI序列对弥漫性轴索损伤诊断的对比研究

目的评价MRI常规FSET2WI、SET1WI序列与EPI序列对弥漫性轴索损伤的诊断价值.材料与方法42例弥漫性轴索损伤患者均进行MRI常规FSET2WI、SET1WI和EPI扫描.29例检查前静脉注射5～10毫克安定.结果FSET2WI、SET1WI序列运动伪影的发生率分别为83.3%、71.4%;EPI序列无一例出现运动伪影.EPI病灶与正常脑白质的对比度显著低于FSET2WI序列(p＜0.001),空间分辨率较FSET2WI、SET1WI序列差,信噪比最高.EPI共显示143个病灶,为FSET2WI显示病灶(174个)的82.2%,SET1WI序列显示133个病灶.对于直径大于1cm的病灶,EPI病灶显示数为FSET2WI序列的91.7%.FSET2WI、SET1WI序列所见的DAI主要并发症,EPI序列大都能显示.结论EPI的对比度与分辨率不如FSET2WI,对脑内小病灶、出血灶及脑底部病灶的显示还存在一定的限度,但EPI扫描时间极短,图像信噪比高、无运动伪影,能保证对脑内大多数病灶的显示,对弥漫性轴索损伤的诊断有重要的诊断价值,尤其对伴有烦噪的急性脑外伤患者或病情不允许进行长时间检查的患者,EPI可代替FSET2WI进行检查.     

MR-angiography of veins in the lower extremities]

Phase contrast MR-angiography (MRA) of veins in the lower extremities was performed in 10 healthy volunteers and 2 patients with deep vein thrombosis of the lower extremities. In all volunteers, MRA demonstrated bilateral large saphenous veins, femoral veins and popliteal veins. Deep veins in the leg were visualized in only 3 out of 20 legs examined, but with compression of the thigh they were visualized in 4 out of 7 legs subjected to compression. In patients with deep vein thrombosis, obstruction of the femoral veins and development of the collateral veins were clearly visualized. It is concluded that MRA may be a valuable technic for the evaluation of the veins patency in the lower extremities.     

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.     

MRA在腹部静脉的应用

目的：评价常规ＭＲＡ和动态增强ＭＲＡ在腹部静脉检查中的价值。材料与方法：腹部静脉ＭＲＡ共５７例行５９人次检查。包括２Ｄ ＴＯＦ５１次，２Ｄ ＰＣ１９次，动态增强ＭＲＡ３０次（其中２Ｄ动态增强１０次，３Ｄ动态增强２０次）。５７例中门脉高压者１８例，布加氏综合征８例，门腔静脉分流术前或术后检查６例，原发性和转移性肝癌９例，其他病变６例，正常组１０例。结果：本组ＭＲＡ表现分别为门脉增粗和静脉曲张；下腔静     

Three-dimensional time-of-flight MR angiography in the evaluation of cerebral aneurysms

We review our preliminary experience with the use of three-dimensional (3D) time-of-flight (TOF) magnetic resonance (MR) angiography (MRA) in the assessment of intra- and extracranial aneurysms. Six patients were examined: Five had intracranial aneurysms and one had a cervical carotid pseudoaneurysm. A 3D rephased gradient recalled echo pulse sequence and maximum intensity projection (MIP) reconstruction algorithm were used. Magnetic resonance angiography, spin echo MR, and conventional angiography were retrospectively reviewed with specific regard to individual vessel visualization, aneurysm depiction, and presence of artifact related to acquisition techniques or MIP reconstruction. All aneurysms were detected on MRA, and anatomical correlation with conventional angiography was excellent. Significant problems included loss of visualization of small vessels, intraluminal signal loss in large vessels, subacute thrombus simulating flow on MIP reconstructions, and limited projections obtainable with MIP techniques. Adequate MRA assessment of aneurysms can be obtained using a combination of T1-weighted spin echo images and 3D TOF MRA. Review of all components of the MRA is required. MRA may be useful in screening asymptomatic patients for intracranial aneurysms as well as in the follow-up of patients treated with balloon occlusion.     

3.OT高时间分辨率对比增强MRA颅内血管成像

目的:评价3.0T高时间分辨率对比增强磁共振血管成像(TR 3D CE-MRA)在颅内血管成像的技术可行性和临床应用价值.方法:经医院伦理委员会批准,回顾性搜集21例患者,采用3.0T磁共振,首先行常规序列T1 WI、T2 WI和TOF MRA扫描,然后在确定痛变处用TR 3D CE-MRA即快速小角度激发梯度回波序列...     

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。     

Assessment of 3D-TOF-MRA at 3.0 Tesla in the characterization of the angioarchitecture of cerebral arteriovenous malformations: a preliminary study

Background: The characterization of brain arteriovenous malformation (AVM) angioarchitecture remains rewarding in planning and predicting therapy. The increased signal-to-noise ratio at higher field strength has been found advantageous in vascular brain pathologies.

Purpose: To evaluate whether 3.0T time-of-flight (TOF) magnetic resonance angiography (MRA) is superior to 1.5T TOF-MRA for the characterization of cerebral AVMs.

Material and Methods: Fifteen patients with AVM underwent TOF-MRA at 3.0T and 1.5T and catheter angiography (DSA), which was used as the gold standard. Blinded readers scored image quality on a four-point scale, nidus size, and number of feeding arteries and draining veins.

Results: Image quality of TOF-MRA at 3.0T was superior to 1.5T but still inferior to DSA. Evaluation of nidus size was equally good at 3.0T and 1.5T for all AVMs. In small AVMs, however, there was a tendency of size overestimation at 3.0T. MRA at 3.0T had increased detection rates for feeding arteries (+21%) and superficial (+13%) and deep draining veins (+33%) over 1.5T MRA.

Conclusion: 3.0T TOF-MRA offers superior characterization of AVM angioarchitecture compared with 1.5T TOF-MRA. The image quality of MRA at both 3.0 and 1.5T is still far from equal to DSA, which remains the gold standard for characterization of AVM.     

头颈部磁共振血管成像技术研究

目的探讨磁共振血管成像（MRA）在头颈部血管疾病的应用价值与限度。方法回顾性分析2010—2011年我院头颈部血管检查的病例,其中头部动脉671例,头部静脉7例,颈部动脉66例,进行三维时间飞越法磁共振血管成像（3D-TOF MRA）、二维时间飞越法磁共振血管成像（2D-TOF MRV）,部分病例做了心室血管造影（CTA）和数字减影血管造影（DSA）检查。磁共振场强为1.5 T,先行标准的磁共振成像（MRI）检查,然后行MRA;MRA采用3D TOF,部分患者还额外采用矢状和/或冠状预饱和技术,用最大密度投影（MIP）演算法处理资料。结果 MRA较好地显示了血管狭窄的部位、程度和范围,其中三维法较二维法显示病变为准确;可以认为,MRA是中风病因诊断和随访最好的无创性检查方法。结论 MRA具有安全、可靠和方便的优点,是头颈部血管疾病筛查的有力工具。     

下肢静脉MRA的评价

目的：探讨MRA在诊断下肢深静脉狭窄和血栓形成的应用价值。材料和方法：25例临床诊断为下肢深静脉血栓形成患者，进行2DTOF法MRA检查，其中3例同时行动态增强MRA（DCEMRA）。检查范围包括下腔静脉下段至小腿静脉。25例中的18例同时行彩超检查。结果：25例MRA共显示静脉以上（包括静脉）深静脉225条，其中正常静脉76条，血栓形成32条，轻度狭窄（1－49％）50条，明显狭窄（50－99％）45条，闭塞（10％）22条。18例MRA与彩超对照可比静脉162条，彩超示正常静脉53条，异常静脉109条，二者显示一致152条，符合率为93．82％（152／162）。结论：MRA对显示下腔静脉狭窄和血栓形成的部位、范围和程序准确性较高，为临床正确诊断和治疗后随访提供了新的无损伤检查手段。