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。     

前交通动脉瘤患者颈内动脉形态及大脑前动脉供血特征研究北大核心CSCD

目的 探讨前交通动脉瘤患者颈内动脉(ICA)形态及大脑前动脉供血特征。方法 回顾性分析资料完整的183例前交通动脉瘤患者临床及MRA、DSA检查数据。根据MRA上双侧前交通动脉(ACA)和ICA是否对称,将前交通动脉瘤患者ICA形态分为4型:Ⅰ型为双侧ACA、ICA对称,Ⅱ型为双侧ACA对称、ICA不对称,Ⅲ型为双侧ACA不对称、ICA对称,Ⅳ型为双侧ACA、ICA不对称。分别超选择插管至左、右ICA作DSA造影,观察前交通脑动脉瘤供血情况。结果 183例前交通动脉瘤患者中ACA对称83例,ACA不对称100例;ICA对称75例,ICA不对称108例;ICA形态分型显示Ⅰ型67例(36.6%),Ⅱ型7例(3.8%),Ⅲ型16例(8.7%),Ⅳ型例93(50.9%)。ICA造影显示,无论ACA或ICA对称与否,前交通动脉瘤主要由一侧ACA供血(125例由左ACA,58例由右ACA供血),另一侧ICA多向同侧ACA供血,不向瘤体供血。结论 前交通动脉瘤患者ICA形态以Ⅰ型(对称)和Ⅳ型(不对称)为主,但无论ACA或ICA对称与否,瘤体多由一侧ACA供血。     

脑动脉瘤的MR血管造影与IA—DSA的对照研究

对经手术证实的２０例脑动脉瘤的ＭＲＡ和ＩＡ－ＤＳＡ的影像进行了对照分析研究，经ＭＲＡ检出１９例（９５％）动脉瘤，１０ｍｍ以下的动脉瘤９例，最小的为４ｍｍ，与ＤＳＡ检出率（１９／２０）相仿。ＭＲＡ的定位符合率为８４％，低于ＤＳＡ（９５％）。１３／１９例（６８％）在ＭＲＡ图象上能显示动脉瘤的瘤颈。作者认为ＭＲＡ是一种新的非侵入性的血管影像方法，可作为脑动脉瘤高危病例的筛选检查，随着ＭＲＡ技术的进一步完善，ＭＲＡ有望在神经外科领域替代部分侵入性血管造影检查。     

易形成前交通动脉瘤的血管模式探讨

目的：对前交通动脉瘤的脑血管造影结果进行分析。材料与方法：采集我院近年来全部经手术证实的２２例前交通动脉瘤的脑血管造影，并以随机选出的非前交通动脉瘤的２５０例脑血管造影为对照组。结果：２５０例对照组的脑血管造影的血管形态、走行基本正常，而２２例前交通动脉瘤的脑血管造影的血管形态及走行则全部表现为作者提出的“易形成前交通动脉瘤的血管模式”，即：一侧前动脉第一段缺如、闭塞或纤细，另一侧颈内动脉则通过开放的前交通动脉同时供应双侧前动脉。结论：（１）如ＣＴ检查示鞍上池或纵裂出血，脑血管造影具有此模式的影像改变，即使脑血管造影未见明确的动脉瘤改变，也应考虑前交通动脉瘤的存在。（２）如脑血管造影为此模式，即使无蛛网膜下腔出血，亦应警惕前交通动脉瘤的发生，并注意随访。     

大脑中动脉狭窄的磁共振血管成像与数字减影血管造影的对照研究

目的 探讨磁共振血管成像(MRA)在大脑中动脉狭窄或闭塞病变中的诊断价值.方法 35例缺血性脑血管病患者先后行MRA及DSA检查,以DSA为金标准,分析MRA对不同程度大脑中动脉狭窄的诊断价值.结果 35例患者70支大脑中动脉中,MRA显示正常血管28支,病变血管42支,病变部位47处,MRA与DSA诊断符合53处,符...     

连续三维时飞法磁共振血管成像对脑动脉的显示能力评价

目的评价连续3D-TOF和高速度编码的三维相位对比法(Venc3D-PC)MRA对脑动脉的显示能力。方法前瞻性选取脑MRI表现正常且连续3D-TOF及高Venc3D-PC磁共振脑动脉成像表现正常者15例,用以评价2种MRA技术显示脑动脉的差异。回顾性选取进行脑动脉MRA及DSA2种检查者43例,以DSA为标准,取其中38侧表现正常者用以评价MRA显示脑动脉的能力。结果3D-TOF与高Venc3D-PC技术显示ACA、MCA或PCA的最大级数均无显著统计学差异,但前者的图像质量优于后者。MRA显示ACA、MCA和PCA的分支级数与DSA均有显著差异性。MRA对ACA和MCA的显示能力均较DSA减少1个级别,对PCA的显示能力差别不大。结论连续3D-TOFMRA对脑动脉的显示能力小于DSA,但已能满足大多数脑血管疾病的临床应用。     

颅内动脉瘤 3D DCE-MRA与DSA对照研究

目的 探讨三维动态增强MR血管造影(3D DCE-MRA)在颅内动脉瘤诊断中的价值. 资料与方法 对39例临床拟诊动脉瘤和常规MRA可疑动脉瘤的患者行3D DCE-MRA,随后行DSA,比较两种方法 对颅内动脉瘤的显示情况. 结果 34例动脉瘤患者中共有动脉瘤41个,3D DCE-MRA对动脉瘤诊断的敏感性为95%,特异性为80%,准确性为85%,3D DCE-MRA与DSA比较,差异无统计学意义(P>0.05). 结论 3D DCE-MRA是一项无创、安全、简便和可靠的诊断颅内动脉瘤的方法,对于颅内较大血管的动脉瘤的显示,可以取代DSA.     

三维增强磁共振血管成像和数字减影血管造影在颈部动脉狭窄闭塞性病变中的对比分析

目的 评价三维增强磁共振血管成像(3D-CE-MRA)诊断颈部动脉狭窄闭塞性病变的准确性及应用价值.方法 对43例可疑颈部动脉狭窄或闭塞的患者分别先后进行3D-CE-MRA和数字减影血管造影(DSA)检查,对成像结果进行对比研究.结果 与DSA相比,3D-CE-MRA 对颈部动脉狭窄闭塞性病变诊断的敏感度为83.0%,特异度为94.1%.结论 3D-CE-MRA对颈部动脉狭窄闭塞性病变的显示具有独特的优势,是一种无创、安全、快速、准确性高的检查方法,可以作为首选的检查方法.     

三维DSA 技术在脑血管病诊断与血管内治疗中的应用

目的评价三维DSA（3D DSA）技术在脑血管病诊断及治疗中的应用价值。方法对60例患者所做3D DSA影像与传统二维DSA（2D DSA）进行比较，分析颅内动脉瘤及动脉狭窄在3D DSA上的影像表现。结果与2D DSA相比，3D DSA在对动脉瘤显示有优越性；但对脑动脉狭窄的显示无明显差异。结论3D DSA可以充分显示动脉瘤的形态、位置以及周围解剖关系，并可以从剖面观察病变血管内情况，对斑块稳定性的判断有一定优势，在介入治疗过程中具有重要价值。     

64层螺旋CT与数字减影血管造影对颅内动脉瘤诊断的比较

目的 通过64层螺旋CT的CT血管造影(CTA)及CT数字减影血管造影(CTDSA)技术与数字减影血管造影(DSA)的比较研究,评价64层螺旋CT在颅内动脉瘤诊断中的临床应用价值。方法 26例临床怀疑颅内动脉瘤的患者实施64层CT和DSA检查,对64层CT图像进行了CTA和DSCTA两种方式的后处理。CTA后处理技术包括容积再现(VR),最大密度投影(MIP)和多平面重建(MPR),在CTA图像基础上用增强数据逐层减去平扫数据,自动去除骨与脑组织,获得CTDSA影像。比较3种技术(DSA、CTA和CTDSA)的特征。结果 26例可疑患者中,DSA和CTDSA发现31个动脉瘤,CTA发现29个动脉瘤。CTA漏掉的2个动脉瘤,直径小于3mm。结论 CTDSA是检查颅内动脉瘤的高度敏感的影像学方法,具有与DSA相当的价值。     

2D time-of-flight MR angiography using concatenated saturation bands for determining direction of flow in the intracranial vessels

We prospectively studied 15 patients to assess 2D time-of-flight (TOF) magnetic resonance angiography (MRA) with concatenated saturation bands for determining the direction of intracranial blood flow. This MRA sequence was compared to T2-weighted spin-echo MRI, 3D-TOF MRA, and intra-arterial angiography (IAA) as regards demonstration of vessels and determination of the direction of flow in the circle of Willis and its branches. The 2D-TOF MRA sequence demonstrated flow in 98.5 % vessel segments identified on IAA, 3D-TOF demonstrating 92 % and spin-echo images 77 %. The direction of flow shown on the 2D-TOF sequence was correct in 94 % when compared to conventional angiography, the remaining six segments not demonstrating flow. In ten patients, the flow abnormalities demonstrated by this MRA technique provided clinical information similar to that of conventional angiography in nine, but it was incomplete in three, and misleading in one. Slow retrograde flow in ophthalmic artery collaterals and differentiation of arteries and veins presented some problems. 2D-TOF MRA with concatenated saturation bands provides flow direction information using widely available, easily applicable TOF techniques, and can be a useful adjunct to MRI and MRA if information on flow direction is needed. Received: 18 October 1995 Accepted: 16 August 1996     

3.0T高分辨三维动态增强磁共振血管造影诊断肾动脉狭窄:与DSA对照研究

目的评价3.0T MR高分辨三维动态增强磁共振血管造影(DCE-MRA)在诊断肾动脉狭窄中的应用价值.材料和方法连续随机对24例疑肾动脉狭窄患者行DCE-MRA和DSA检查,磁共振血管造影联合采用透视触发(BOLUS-TRICK)和敏感度编码扫描技术(sensitivity encoding,SENSE),后处理使用"肥皂泡"(Soap-Bubble)曲面重组技术,定量分析肾动脉长度、直径、狭窄程度、信噪比、对比噪声比,分5级计算DCE-MRA对肾动脉狭窄的敏感性、特异性、阳性预测值、阴性预测值和准确性.用直线回归与相关法评价总体CE-MRA与DSA在诊断肾动脉狭窄和狭窄分级方面的一致性.结果24例患者共检出肾动脉48支,左、右侧肾动脉长度分别是(37.5±8.2)mm、(49.6±9.7)mm;直径为(4.4±0.6)mm、(4.1±0.6)mm.与DSA结果对照,DCE-MRA诊断肾动脉狭窄程度在50%～75%之间、≥75%的敏感性、特异性、阳性预测值、阴性预测值、准确性分别为91.7%、88.9%、73.3%、96.9%、89.6%;90%、100%、100%、97.4%、98.0%.3D DCE-MRA与DSA在诊断肾动脉狭窄和狭窄分级方面关系密切,r=0.985(P＜0.01),回归方程Y∧=0.972 2.281X.结论3.0T MR高分辨三维动态增强磁共振血管造影是一种扫描时间短、空间、时间分辨率极高的肾动脉成像技术,结合"肥皂泡"软件重建和分析,对肾动脉狭窄部位、程度作出可靠诊断,为临床治疗方案的选择提供重要依据.     

Artefact on MRA following aneurysm clipping: an in vitro study and prospective comparison with conventional angiography

Using both an experimental model and clinical cases, we looked at the artefact produced by Aesculap titanium-alloy aneurysm clips on MRA. Experimentally, the volume affected by artefact was 50 % less when the clip was imaged lying parallel to the main ferromagnetic field than when lying perpendicular to it. Clinically, MRA was prospectively compared with digital subtraction angiography (DSA) in nine patients who had undergone aneurysm clipping. One patient with a non-diagnostic MRA due to movement artefact was excluded. In all other cases there was an area of signal loss surrounding the clips, obscuring the immediately adjacent vessel segments. There was good demonstration of the adjacent bifurcations in five cases and the contralateral circulation was seen well in all patients. In three cases in which the adjacent bifurcations were not seen, considerable vasospasm was suggested by MRA and confirmed with DSA. In one patient an unclipped contralateral ophthalmic artery aneurysm was identified using both modalities. In this series there were no adverse events relating to clips in either static or time-varying magnetic fields. Received: 29 November 1998 Accepted: 24 December 1998     

CTA对急性期动脉瘤性蛛网膜下腔出血的病因诊断

目的探讨CT血管造影(CTA)对于急性期动脉瘤性蛛网膜下腔出血(SAH)的病因学诊断价值。资料与方法回顾性分析经CT平扫及腰穿明确诊断的自发性SAH38例患者资料,在SAH急性期(3～10天)做CTA并与数字减影血管造影(DSA)全脑动脉造影检查比较。结果38例患者中MSCTA发现动脉瘤32例,显示瘤体、瘤颈、载瘤动脉和与周围血管及颅骨的关系清晰、确切。对动脉瘤的检出敏感性为96.97%,特异性为100%。结论MSCTA是简单、快速、无创、安全、可靠的脑血管成像技术,在一定程度上可替代DSA检查,可作为SAH急性期患者病因诊断的首选筛查方法。     

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。     

Evaluation of the carotid artery bifurcation: comparison of magnetic resonance angiography and digital subtraction arch aortography

Summary Thirty-four carotid artery bifurcations were examined using both magnetic resonance angiography (MRA) and digital subtraction arch aortography to determine their accuracy when compared to selective carotid angiography. The sensitivity of MRA was 73% and its specificity was 91% when compared with selective carotid angiography. The sensitivity of arch aortography was 27% and its specificity was 100%.     

Preliminary experience with dynamic MR projection angiography in the evaluation of cervicocranial steno-occlusive disease

The application of a contrast-enhanced, two-dimensional MR technique, which provides dynamic projection angiograms at a subsecond temporal frame rate for depiction of the cervical and intracranial arteries, was evaluated in three healthy volunteers and seven patients with various cervicocranial steno-occlusive diseases. Intra-arterial digital subtraction angiography (DSA) served as standard of reference for findings in the patients. Magnetic resonance projection angiography (MRPA) was performed on a standard 1.5-T clinical MR imaging system at intravenous injection of a single dose of contrast agent (0.1 mmol/kg GdDTPA-BMA). Sixty consecutive images of the cerebral circulation were acquired at a temporal frame rate of 900 ms per image in the coronal plane. The collateral flow and the perfusion of the compromised vessel territory were readily assessed by MPRA in patients with occlusion of the internal cerebral artery (ICA) or middle cerebral artery (MCA). The leptomeningeal collateralisation of these patients was displayed in a dynamic fashion. Furthermore, quantitative perfusion measurement provided a difference between both MCA territories in the time to peak (ΔDTTP) of the contrast bolus of 1.12 ± 0.28 s in five patients with severe stenosis or occlusion of the ICA (healthy volunteers 0.19 ± 0.05 s). However, important pathological findings, such as the evaluation of carotid artery stenoses and the intracranial collateral flow pattern in patients with severe carotid stenoses, were not sufficiently assessable as compared with DSA. We conclude that the possibility of obtaining simultaneously information about morphology and perfusion dynamics of the cervicocranial vessels is unique in MPRA as compared with other MR techniques. However, in the applied form, the technique is not a reliable tool for the complete evaluation of the cervicocranial vessels in patients with steno-occlusive disease. Received: 27 January 2000/Revised: 11 July 2000/Accepted: 13 July 2000     

Evaluation of Anterior Ethmoidal Artery by 320-Slice CT Angiography with Comparison to Three-Dimensional Spin Digital Subtraction Angiography: Initial Experiences

Objective

To explore the usefulness of 320-slice CT angiography (CTA) for evaluating the course of the anterior ethmoidal artery (AEA) and its relationship with adjacent structures by using three-dimensional (3D) spin digital subtraction angiography (DSA) as standard reference.

Materials and Methods

From December 2008 to December 2010, 32 patients with cerebrovascular disease, who underwent both cranial 3D spin DSA and 320-slice CTA within a 30 day period from each other, were retrospectively reviewed. AEA course in ethmoid was analyzed in DSA and CTA. In addition, adjacent bony landmarks (bony notch in medial orbital wall, anterior ethmoidal canal, and anterior ethmoidal sulcus) were evaluated with CTA using the MPR technique oriented along the axial, coronal and oblique coronal planes in all patients. The dose length product (DLP) for CTA and the dose-area product (DAP) for 3D spin DSA were recorded. Effective dose (ED) was calculated.

Results

The entire course of the AEA was seen in all 32 cases (100%) with 3D spine DSA and in 29 of 32 cases (90.1%) with 320-slice CTA, with no significant difference (p = 0.24). In three cases where AEA was not visualized on 320-slice CTA, two were due to the dominant posterior ethmoidal artery, while the remaining case was due to diminutive AEA. On MPR images of 320-slice CT, a bony notch in the orbital medial walls was detected in all cases (100%, 64 of 64); anterior ethmoidal canal was seen in 28 of 64 cases (43.8%), and the anterior ethmoidal sulcus was seen in 63 of 64 cases (98.4%). The mean effective dose in CTA was 0.6 ± 0.25 mSv, which was significantly lower than for 3D spin DSA (1.3 ± 0.01 mSv) (p < 0.001).

Conclusion

320-slice CTA has a similar detection rate for AEA to that of 3D spin DSA; however, it is noninvasive, and may be preferentially used for the evaluation of AEA and its adjacent bony variations and pathologic changes in preoperative patients with paranasal sinus diseases.     

Acute subarachnoid Haemorrhage: 3D time-of-flight MR angiography versus intra-arterial digital angiography

To evaluate the efficacy and reliability of 3D time-of-flight MR angiography (TOF MRA) as a noninvasive procedure, 27 patients with acute subarachnoid haemorrhage (SAH) were studied with MRA immediately before or after intra-arterial digital subtraction angiography (DSA). 3DTOF MRA was performed with an axial slab of 60 mm centred on the circle of Willis and isotropic voxels. DSA showed 22 aneurysms and 1 dural arteriovenous fistula in 21 patients; the aneurysms ranged in size from 2 to 8 mm. MRA failed to show 2 small aneurysms, at the origin of the posterior and anterior communicating arteries. The 3D display of the intracranial vessels obtained with maximum intensity projection (MIP) or targetted MIP sometimes rendered the aneurysms better than DSA. However, due to its high spatial resolution, DSA more clearly defined the overall anatomy of the walls of the normal and abnormal vessels.1992 Scientific Award of the ESNR