小腿加压3.0T MRA评估糖尿病下肢血管病变的价值探讨

目的 以DSA为金标准评价小腿加压法3.0 T 增强磁共振血管成像(CE-MRA)在糖尿病下肢血管病变的应用价值.方法 对61例2型糖尿病合并下肢血管病变患者进行双下肢MRA检查,患者平均病程(11.6±6.0)年.使用3.0 T CE-MRA,其中小腿袖带加压后成像者(即加压组)31例,常规成像者30例(即常规组),...     

DSA静脉造影诊断下肢静脉疾病

目的：探讨DSA下肢深静脉造影诊断下肢静脉疾病的价值。方法：56例（66条）下肢静脉病变的患者在DSA下行下肢深静脉顺、逆行造影,其中16例行经皮穿刺腘静脉插管造影。结果：根据主要X线表现将下肢静脉疾病分为：下肢静脉曲张10条（15%）、下肢深静脉瓣膜功能不全34条（52%）和深静脉血栓形成22条（33%）。根据深静脉逆流程度分为：Ⅰ级10条,Ⅱ级14条,Ⅲ级8条,Ⅳ级2条。结论：在DSA下行下肢深静脉造影,能为临床提供可靠的影像学诊断依据,以利治疗方案的选择。     

三维动态增强MRA与DSA对原发性Budd-Chiari综合征分型诊断的对照研究

目的:探讨3DDCE MRA和DSA对原发性Budd-Chiari综合征的分型诊断能力。方法:回顾性分析46例行3DDCE MRA和DSA检查的原发性Budd-Chiari综合征患者的病例资料,所有患者经DSA证实至少有一支肝静脉或入右心房段及肝后段下腔静脉存在病变且无肿瘤、血栓等基础疾病。对所有患者的3DDCE MRA图像质量进行评价(1～4分,依次为优、良、中和差),以DSA检查作为金标准,评估3DDCE MRA诊断BCS的能力,包括检出静脉病变的总敏感度、特异度及诊断准确度,显示下腔静脉及肝静脉(肝左、肝右及肝中静脉)病变各自的敏感度以及发现副肝静脉的敏感度,采用Kappa检验评估这两种检查方法对BCS分型诊断的一致性。结果:46例中44例的3DDCE MRA图像质量评分为3～4分,仅2例图像质量为2分。3DDCE MRA正确诊断BCS 45例。46例患者共184支血管段中DSA共检出151支静脉病变,3DDCE MRA正确诊断141支、误诊2支,MRA发现静脉病变的总敏感度为93.4%(141/151),特异度为94.0%(31/33);发现下腔静脉病变的敏感度为94.9%(37/39),发现肝右、肝中及肝左静脉的敏感度分别为94.1%(32/34)、92.3%(36/39)和92.3%(36/39);显示副肝静脉的敏感度为83.3%(25/30)。3DDCE MRA对所有患者的分型诊断符合率为86.7%(39/45),且与DSA之间存在高度一致性(Kappa=0.667,P<0.05)。结论:3DDCE MRA可较准确地对原发性BCS进行诊断和分型,能够对患者的介入治疗方案的制订和导管入路的选择提供帮助。     

症状性颅、颈部动脉狭窄在3.0T上的MRA与DSA比较研究

目的前瞻性分析3．0T应用SENSE技术的高分辨率对比增强容积扫描MRA（CEMRA）和3DTOFMRA在临床疑有颅、颈部动脉狭窄性病变患者中的应用价值。方法46例临床怀疑颅、颈部动脉狭窄的患者接受头颅MRI平扫、头颅3DTOFMRA和颈部CEMRA检查。动脉狭窄的程度与DSA检查结果进行相关性比较。结果MRA显示各段颅、颈部动脉狭窄的不同程度和DSA检查显著相关（Rs=0．97,P〈0．01）。以DSA结果为金标准,狭窄程度超过50％者MRA诊断灵敏度为100％,特异度为99．4％、准确率为99．4％。结论3．0T的3DTOFMRA和高分辨率CEMRA检查能可靠和有效地评价颅、颈部动脉狭窄性病变,可作为DSA术前必要的检查技术,或可替代传统DSA诊断性检查。     

头颈部血管闭塞性疾病的MRA与DSA对照研究

目的通过与DSA对照,探讨MRA在头颈部血管闭塞性疾病的应用价值与限度。方法回顾性分析头颈部血管检查的病例32例,均进行2D-TOFMRA和DSA检查,检查结果进行对照分析。结果32例经DSA检查8例为正常,余24例中病变血管共38支,其中轻度狭窄12支,中度狭窄8支,重度狭窄8支,闭塞10支;MRA正确诊断26支,总体准确率为约70%。椎动脉假阳性较高,达62.5%。结论MRA可以作为颈动脉和大脑动脉环闭塞性疾病的筛选方法,但不适宜应用于椎动脉。     

脑血管病变三维PC法MRA与动脉DSA的对照研究

目的 :通过与动脉 DSA结果的对照 ,研究三维 PC法 MRA对于检测各类脑血管病变的可信性。方法 :对临床或 MRI表现疑为或需排除脑血管病变的 5 9例兼作 MRA和 DSA检查 ,评价三维 PC法 MRA检测颅内各种血管病变的灵敏度、特异度、假阳性和假阴性率。结果 :MRA检出大于 5 mm的动脉瘤的灵敏度和特异度均达 10 0 %。但小于 5 mm者难以检出 ,使检出总灵敏度下降为 81.8%。 MRA检出 AVM的灵敏度为 92 .3%、特异度为 10 0 % ,畸形血管团及其主要供血动脉和引流静脉均可被 MRA显示。MRA检出颈内动脉 -海绵窦瘘的灵敏度和特异度均为 10 0 % ,表现十分典型。 MRA检出脑血管主干闭塞的灵敏度为 10 0 % ,特异度为 86 .70 % ,高度狭窄者可能过诊为闭塞。 MRA对于颅内占位病变引起的血管移位能全部显示 ,对于细小的肿瘤血管和肿瘤血供无法显示。结论 :MRA在脑血管病变的诊断上显示出很大的应用价值 ,对动静脉畸形、动静脉瘘、血管闭塞和血管移位的检测已有较高的灵敏度和特异度 ,对于较大动脉瘤的显示较好 ,对于小动脉瘤的检出率仍低 ,MRA对于肿瘤血管的检测基本无效。     

3T TOF MRA在颅内血管病变中的应用——与DSA对照

目的:评价3T TOF-MRA在颅内血管病变中的诊断价值。材料和方法:37例临床上具有神经系统症状的病人前瞻性行3T TOF-MRA及脑血管数字减影血管造影检查(DSA)。其中男性16例,女性21例,平均年龄53.5±13.5(21～74)岁。MRA图像分别由2位神经影像医师阅读,DSA图像由神经介入医师阅读,其结论与前两者有分歧的地方,经讨论确立一致观点。以DSA检查作为标准,评价3T TOF-MRA诊断颅内血管性病变的敏感性、特异性及准确性。结果:DSA检查14例15个动脉瘤,5例动静脉畸形,3例3侧大脑中动脉狭窄,1例大脑后动脉闭塞;14例未见明显异常。TOF-MRA准确显示了其中的22处病变(14个动脉瘤,4个动静脉畸形及4处血管狭窄),但误诊1例,假阳性4例,假阴性2例;其总体诊断敏感性、特异性、准确性分别为91.3%、75%和为85%。结论:3.0T TOF-MRA能够很好地显示颅内血管病变,是一种可靠的无创评价方法。     

MRA在诊断颅内动脉瘤中的应用

目的：研究MRA诊断颅内动脉瘤的原理与方法，优势与不足以及临床价值。方法：选择经DSA证实为颅内动脉瘤的息者30例，行三维MRA及MRI检查，全部病例均经手术证实。结果：MRA对颅内动脉瘤的敏感性为90％，结合原始断层图像和MRI，敏感性则高达97％，较准确显示了3mm以上动脉瘤的形态、大小及与载瘤动脉的关系。对于检测血栓性动脉瘤MRA优于DSA影像。结论：MRA是一种无创伤的血管检查技术．可准确显示动脉瘤。对于Willis环区动脉瘤，MRA可取代常规血管造影。     

3.0T MRA检查对蛛网膜下腔出血病人诊断及治疗方案制定的临床价值

摘要目的本研究主要评价3.0T非增强磁共振血管成像(MRA)对蛛网膜下腔出血(SAH)病人的诊断及制定治疗方案的临床价值。方法共165例SAH病人在DSA前先进行三维时间飞跃法MRA(3D-TOF-MRA)检查,并判断动脉瘤是否适合弹簧圈栓塞(用或不用球囊或支架辅助)、外科夹闭或保守治疗。将根据3D-TOF-MRA制定的治疗方案与实际采取的治疗方案或通过DSA制定的治疗方案相比较。     

Willis环的3D MRA、3D FSPGR和DSA对比研究

目的　以DSA结果为标准 ,比较 3DTOF、3DPC、3DFSPGR序列及联合运用时对Willis环各组成血管的显示能力。方法　同时进行增强MRA和全脑DSA检查的病人 5 5例 ,对所得的 3DTOF源图像、3DTOFMIP、3DPCMIP、3DFSPGR图像上显示的Willis环组成血管进行判定和联合分析 ,并与DSA结果比较 ,计算各种MRA图像对Willis环组成血管中ACOA、PCOA、P1、A1显示的敏感性、特异性及阴性、阳性预测值。结果　各种评定方法对A1、P1评定的敏感性在 94.12 %以上 ,特异性和阳性预测值均达 10 0 %。对于ACOA、PCOA ,3DTOF源图像、3DFSPGR图像和联合分析结果的敏感性、特异性、阳性预测值和阴性预测值均近似 ;敏感性及阴性预测值均明显高于 3DTOF和 3DPCMIP ,阳性预测值均低于MIP图像。结论　 3DPCMIP ,3DTOF源图像和 /或 3DFSPGR联合可能不仅提高Willis环显示的特异性 ,还可提高其显示的敏感性。     

3.0 T MR对比增强全心冠状血管成像对冠状静脉系统的解剖学研究

目的 探讨3.0 T MR对比增强全心冠状血管成像(CE CMRA)对冠状静脉解剖的研究价值.方法 43例受试者行3.0 T CE CMRA,采用自由呼吸导航门控、心电触发和非选择性反转恢复(IR)准备脉冲的3D扰相位梯度回波(FLASH)序列.采用32通道体部相控阵线圈进行数据获取.冠状静脉的图像质量由4分法进行评价.连续变量表达为(-x)±s,用配对t检验评价CS窦口前后径及上下径的差异.结果 40例受试者成功完成3.0 T CE CMRA检查,其中38例(95.0%)受试者的图像能够进行评价.左心室后静脉(PVLV)及左边缘静脉(LMV)距冠状窦(CS)窦口的距离分别为(3.34±0.90)及(6.12±1.02)cm.CS、后室间静脉(PIV)、PVLV、LMV及前室间静脉(AIV)的平均图像质量得分分别为(4.0±0.0)、(3.4±0.5)、(3.4±0.5)、(3.0±0.8)及(3.3±0.5)分.CS窦口的上下径[(1.10±0.26)cm]大于前后径[(0.83±0.19)cm],差异有统计学意义(t=-4.31,P<0.05).结论 3.0 T MR CE CMRA能够清晰地评价冠状静脉解剖.     

3T high-spatial-resolution contrast-enhanced MR angiography of the intracranial venous system with parallel imaging

The diagnostic image quality of contrast-enhanced (CE) 3D MR venography (MRV) was prospectively compared with that of 2D time-of-flight (TOF) MRV and contrast-enhanced 3D magnetization-prepared rapid acquisition of gradient echo (MPRAGE) sequences for the visualization of the intracranial venous system at 3T in 22 patients. CE MRV provides high-quality images and was shown to be superior to TOF MRV and MPRAGE sequences in visualizing the normal intracranial venous system.     

3.0T MR颈动脉成像技术

目的：探讨颈动脉“亮血”3D-TOF MRA配合“黑血”血管壁MR成像技术对血管病变显示的能力。方法：采用颈动脉专用表面线圈,对31例疑有颈动脉病变的脑卒中患者行MR多序列(“亮血”3D-TOF、“黑血”T1WI、T2WI)检查,并进行颈动脉狭窄程度和病变分类,比较“亮血”序列和“黑血”序列检测的阳性率。结果：31例受...     

Brain arteriovenous malformation diagnosis: value of time-resolved contrast-enhanced MR angiography at 3.0T compared to DSA

Introduction

This study was conducted in order to evaluate the value of time-resolved contrast-enhanced magnetic resonance angiography (TR-CE-MRA) with a 3.0-T magnetic field compared to digital subtraction angiography (DSA) as the reference standard for the diagnosis of brain arteriovenous malformation (bAVM).

Methods

Nineteen patients with 19 angiographically confirmed untreated bAVM were investigated with both DSA and TR-CE-MRA for the initial diagnosis. Examinations were compared by two independent readers. Interobserver agreement and intermodality agreement with respect to nidus size, arterial feeders, and venous drainage were determined using the K statistic test. Also, the quality of the TR-CE-MRA images was evaluated.

Results

Seventeen of the 19 bAVM (89.5%) detected with DSA were diagnosed with TR-CE-MRA. Interobserver agreement for TR-CE-MRA was good for nidus size, venous drainage, and arterial feeders (K?=?0.75, 95% CI 0.50–1.00; K?=?0.77, 95% CI 0.54–1.00; and K?=?0.80, 95% CI 0.59–1.00 respectively). Intermodality agreement was good for nidus size and venous drainage (K?=?0.75, 95% CI 0.49–1.00 and K?=?0.77, 95% CI 0.54–1.00, respectively) and moderate for arterial feeders (K?=?0.44, 95% CI 0.17–0.70).

Conclusion

TR-CE-MRA at 3.0?T has a good sensitivity for bAVM detection and good agreement with DSA for determining nidus size and the type of venous drainage, suggesting that TR-CE-MRA is potentially a reliable tool for the diagnosis and assessment of bAVMs. However, it still suffers from low spatial resolution and vessel superposition, making differentiation of the arterial feeders of the nidus difficult at times.     

Follow-up of coiled cerebral aneurysms at 3T: comparison of 3D time-of-flight MR angiography and contrast-enhanced MR angiography

BACKGROUND AND PURPOSE: Our aim was to compare contrast-enhanced MR angiography (CE-MRA) and 3D time-of-flight (TOF) MRA at 3T for follow-up of coiled cerebral aneurysms.MATERIALS AND METHODS: Fifty-two patients treated with Guglielmi detachable coils for 54 cerebral aneurysms were evaluated at 3T MRA. 3D TOF MRA (TR/TE = 23/3.5; SENSE factor = 2.5) and CE-MRA by using a 3D ultrafast gradient-echo sequence (TR/TE = 5.9/1.8; SENSE factor = 3) enhanced with 0.1-mmol/kg gadobenate dimeglumine were performed in the same session. Source images, 3D maximum intensity projection, 3D shaded surface display, and/or 3D volume-rendered reconstructions were evaluated in terms of aneurysm occlusion/patency and artifact presence.RESULTS: In terms of clinical classification, the 2 MRA sequences were equivalent for 53 of the 54 treated aneurysms: 21 were considered fully occluded, whereas 16 were considered to have a residual neck and 16 were considered residually patent at follow-up MRA. The remaining aneurysm appeared fully occluded at TOF MRA but had a residual patent neck at CE-MRA. Visualization of residual aneurysm patency was significantly (P = .001) better with CE-MRA compared with TOF MRA for 10 (31.3%) of the 32 treated aneurysms considered residually patent with both sequences. Coil artifacts were present in 5 cases at TOF MRA but in none at CE-MRA. No relationship was apparent between the visualization of patency and either the size of the aneurysm or the interval between embolization and follow-up.CONCLUSION: At follow-up MRA at 3T, unenhanced TOF and CE-MRA sequences are similarly effective at classifying coiled aneurysms as occluded or residually patent. However, CE-MRA is superior to TOF MRA for visualization of residual patency and is associated with fewer artifacts.

Regular imaging follow-up of patients with intracranial aneurysms treated with Guglielmi detachable coils (GDCs) is necessary because of the risk of aneurysm reconfiguration (ie, coil compaction and/or growth of a residual aneurysm neck or body remnant) with time.^1–4 Of the techniques available for monitoring the results of embolization therapy, MR angiography (MRA) has emerged as the technique of choice at most institutions. Advantages over conventional digital subtraction angiography (DSA) include minimal invasiveness with no associated risk of neurologic complications, reduced patient discomfort and inconvenience, greater cost savings, and no exposure to ionizing radiation or potentially nephrotoxic iodinated contrast media. An alternative minimally invasive procedure is CT angiography (CTA). However, whereas this technique has proved useful for aneurysm detection,^5–9 limitations to its use for follow-up of coiled aneurysms include streak and other coil-related artifacts.^10–12 Moreover, CTA also requires exposure to ionizing radiation and iodinated contrast media, which may be undesirable if repeat follow-up examinations are required.Studies performed to date have shown that nonenhanced 3D time-of-flight (TOF) MRA sequences on 1.5T scanners are frequently satisfactory for the follow-up of coiled aneurysms^1–20 but that 3D TOF MRA on 3T scanners offers improved depiction of both treated²¹ and untreated²² aneurysms due to the greater spatial and contrast resolution achievable at a higher magnetic field strength. Concerning the use of gadolinium contrast material, some studies have suggested that contrast-enhanced MRA (CE-MRA) provides no additional benefit compared with nonenhanced 3D TOF MRA at either 1.5T^15,20 or 3T,²¹ whereas other studies have shown that CE-MRA permits better visualization of coiled aneurysms and of branch arteries and residual neck, particularly in large or giant aneurysms.^14,22–26 Recently, Nael et al²⁷ demonstrated that CE-MRA with highly accelerated (×4) parallel acquisition at 3T provides comparable information to accelerated (×2) 3D TOF MRA at 3T for the characterization of untreated intracranial aneurysms without the known drawbacks of TOF MRA techniques (ie, prolonged acquisition time, spin saturation, and flow-related artifacts). On the other hand, Gibbs et al²⁸ showed that with elliptic-centric imaging, 3D TOF MRA at 3T is superior to CE-MRA at 3T in terms of both image quality and detection of untreated intracranial aneurysms. Our study was performed to evaluate CE-MRA with accelerated (×3) parallel acquisition at 3T compared with accelerated (×2.5) 3D TOF MRA at 3T for the follow-up of GDC-treated intracranial aneurysms. To the authors’ knowledge, this is the first study to compare MRA sequences at 3T for follow-up of coiled aneurysms.     

Improved venous suppression and spatial resolution with SENSE in elliptical centric 3D contrast-enhanced MR angiography.

The elliptical centric (EC) view order samples a 3DFT acquisition from the center of k-space outward, and when applied to contrast-enhanced MR angiography (CE-MRA) provides intrinsic venous suppression. This is because the veins enhance several seconds after the scan is initiated, and are thus encoded solely by noncentral k-space frequencies. A separate method, sensitivity encoding (SENSE), accelerates the k-space sampling rate by reducing the phase FOV or, equivalently, by increasing the k-space sampling interval, and has been used to increase spatiotemporal resolution. We hypothesized that by combining SENSE with EC, sampling of central k-space would be accelerated and the k-space radius at which the veins first showed contrast enhancement would be increased over a reference scan, thus providing improved venous suppression and spatial resolution without additional scan time. This hypothesis was studied with the use of phantom and carotid CE-MRA experiments, and the results demonstrated an approximate 25% reduction in venous signal when SENSE was used.     

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.     

Intracranial tumors examined by intraarterial DSA: a comparative angiography study

We compared intraarterial digital subtraction angiography (DSA) studies with those of conventional angiography, performed for 24 patients who had intracranial tumors. Intraarterial DSA is more effective in evaluating tumoral blush and venous phase, but neovascularization can be judged better by conventional angiography. In most cases, intraarterial DSA can replace conventional angiography for the diagnostic and preoperative evaluation of intracranial tumors. However, conventional angiography remains the technique of choice for the evaluation of neovascularization or if the patient is not cooperative.