Magnetic resonance angiography of intracranial aneurysms: comparison with intra-arterial digital subtraction angiography

Summary Magnetic resonance angiography (MRA) with flow rephased gradient-echo sequences is a new non-invasive method for vascular imaging. We compared MRA and intra-arterial digital subtraction angiography in 18 patients with intracranial aneurysms to test whether MRA presently provides an alternative to cerebral angiography for the diagnosis of these anomalies. MRA showed 19 of the 22 aneurysms detected (86.4%). However, problems, especially with turbulent or slow flow, resulted in 6 studies (27.3%) with limited and 2 with questionable demonstration of an aneurysm, and 1 false negative study. At present, MRA is definitely inferior to angiography for the demonstration of intracranial aneurysms, due to its lower resolution and other limitations.     

数字减影CT血管成像与三维数字减影血管造影(DSA)技术检测颅内动脉瘤的比较研究

目的评价数字减影CT血管成像技术对颅内动脉瘤诊断的准确度,将三维旋转数字减影血管造影(DSA)技术作为参考标准,进行单中心大队列样本的研究。材料与方法本研究免除机构审查委员会批准,因为它本质上是回顾性的     

数字减影CT血管造影对颅内动脉瘤的诊断价值

目的 :探讨数字减影CT血管造影(digital subtraction CT angiography,DSCTA)对颅内动脉瘤的诊断价值。方法 :回顾性分析30例颅内动脉瘤合并自发性蛛网膜下腔出血患者的临床及影像学资料,并行MIP、VR观察动脉瘤。结果:30例共37个动脉瘤,前交通动脉6个,大脑前动脉2个,大脑中动脉9个,后交通动脉16个,基底动脉2个,颈内动脉2个。23例单发,7例多部位动脉瘤。DSCTA共发现35个动脉瘤,漏诊2个。动脉瘤大小3 mm×2.9 mm~12 mm×10 mm。18例行弹簧钢圈栓塞。7例行开颅夹闭术。DSCTA检查的敏感度为94.59%,特异度为100%,准确率为94.59%。结论:DSCTA是一种快速准确诊断颅内动脉瘤的非侵袭性检查方法,对颅内动脉瘤的检出具有极高的敏感性和特异性,为临床治疗方案的选择提供了可靠依据,有极高的临床价值。     

数字减影CT血管成像对颅内小动脉瘤的诊断价值

目的：评价数字减影 CT 血管成像(DSCTA)在颅内小动脉瘤诊断中的价值。方法回顾性分析92例经数字减影血管造影(DSA)或手术确诊为颅内动脉瘤患者的临床及 CT 影像资料,比较 DSCTA 和常规 CT 血管成像(CTA)2种技术对颅内动脉瘤检测的准确性。结果92例患者经证实共有102个动脉瘤,DSCTA 检出其中100个,常规 CTA 检出其中89个(χ2=8.707,P =0.003)。DSCTA 漏诊海绵窦段和床突下段动脉瘤各1例,而常规 CTA 漏诊13例床突下段及海绵窦段与颅骨紧贴<5.0 mm 的小动脉瘤。进一步将<3.0 mm 和3.0~5.0 mm 的动脉瘤合并计算,DSCTA 对检出5.0 mm 以下动脉瘤的敏感性显著高于常规CTA 技术(χ2=8.393,P =0.004)。结论DSCTA 对颅内动脉瘤诊断优于常规 CTA,尤其对颅底毗邻小动脉瘤的诊断有明显的优势,可作为筛查和诊断颅内动脉瘤的首选检查技术。     

Intravenous digital subtraction angiography in intracranial aneurysms

Intravenous digital subtraction angiography was undertaken in 121 patients with known intracranial aneurysms. Its role in the management of these patients and its diagnostic accuracy have been assessed.     

Follow-up after embolization of ruptured intracranial aneurysms: A prospective comparison of two-dimensional digital subtraction angiography, three-dimensional digital subtraction angiography, and time-of-flight magnetic resonance angiography

Introduction

To prospectively compare of the diagnostic value of digital subtraction angiography (DSA) and time-of-flight magnetic resonance angiography (TOF-MRA) in the follow-up of intracranial aneurysms after endovascular treatment.

Methods

Seventy-two consecutive patients were examined 3?months after the embolization. The index tests included: two-dimensional DSA (2D-DSA), three-dimensional DSA (3D-DSA), and TOF-MRA. The reference test was a retrospective consensus between 2D-DSA images, 3D-DSA images, and source rotational DSA images. The evaluation included: detection of the residual flow, quantification of the flow, and validity of the decision regarding retreatment. Intraobserver agreement and interobserver agreement were determined.

Results

The sensitivity and specificity of residual flow detection ranged from 84.6?% (2D-DSA and TOF-MRA) to 92.3?% (3D-DSA) and from 91.3?% (TOF-MRA) to 97.8?% (3D-DSA), respectively. The accuracy of occlusion degree evaluation ranged from 0.78 (2D-DSA) to 0.92 (3D-DSA, Cohen??s kappa). The 2D-DSA method presented lower performance in the decision on retreatment than 3D-DSA (P?<?0.05, ROC analysis). The intraobserver agreement was very good for all techniques (???=?0.80?C0.97). The interobserver agreement was moderate for TOF-MRA and very good for 2D-DSA and 3D-DSA (???=?0.72?C0.94).

Conclusion

Considering the invasiveness of DSA and the minor difference in the diagnostic performance between 3D-DSA and TOF-MRA, the latter method should be the first-line modality for follow-up after aneurysm embolization.     

Intraarterial digital subtraction angiography for definitive diagnosis of intracranial aneurysms

Comparisons between digital subtraction angiography and conventional angiography have frequently been made in the radiologic literature, and the high quality and several advantages of the former have been reported. In this study, 101 patients with intracranial aneurysms were examined only by intraarterial digital subtraction angiography; no conventional angiography was used. High-quality images were consistently obtained, facilitating an accurate and definitive diagnosis of intracranial aneurysm. Magnification radiography and stereography using intraarterial digital subtraction angiography were done to obtain a more precise diagnosis. Five small intracranial aneurysms with diameters of 1.0 to 2.0 mm could be detected. The procedure was considered to be as reliable and as safe as conventional angiography, used previously. Important advantages of intraarterial digital subtraction angiography include reduced procedural time and decreased contrast agent burden, factors that will ensure broader application of this procedure for definitive diagnosis of intracranial aneurysms as experience with the technique accumulates.     

三维数字减影血管造影在颅内动脉瘤诊疗中的应用价值

目的：探讨3D—DSA在颅内动脉瘤诊断和治疗中的应用价值。方法：对蛛网膜下腔出血患者常规行DSA检查，发现病变或可疑病变后行3D—DSA检查。结果：26例颅内动脉瘤中检出动脉瘤31枚，其中后交通9枚，C1段3枚，C2段5枚，C3段3枚，前交通6枚，大脑中3枚。椎动脉动2枚。3例2D—DSA未见病变3D—DSA确诊，5例因血管重叠3D—DSA排除了动脉瘤。6枚GDC栓塞，5枚手术夹闭，2枚颈内动脉可脱性球囊封阻术。结论：3D—DSA极大提高了脑血管造影检查的准确性和可靠性，为动脉瘤的介入治疗和手术夹闭提供了可靠保障，在临床诊疗中具有很高的应用价值。     

CT angiography,MR angiography and rotational digital subtraction angiography for volumetric assessment of intracranial aneurysms. An experimental study

The purpose of our experimental study was to assess the accuracy and precision of CT angiography (CTA), MR angiography (MRA) and rotational digital subtraction angiography (DSA) for measuring the volume of an in vitro aneurysm model. A rigid model of the anterior cerebral circulation harbouring an anterior communicating aneurysm was connected to a pulsatile circuit. It was studied using unenhanced 3D time-of-flight MRA, contrast-enhanced CTA and rotational DSA angiography. The source images were then postprocessed on dedicated workstations to calculate the volume of the aneurysm. CTA was more accurate than MRA (P=0.0019). Rotational DSA was more accurate than CTA, although the difference did not reach statistical significance (P=0.1605), and significantly more accurate than MRA (P<0.00001). CTA was more precise than MRA (P=0.12), although this did not reach statistical significance. Rotational DSA can be part of the diagnosis, treatment planning and support endovascular treatment of intracranial aneurysms. The emerging endovascular treatment techniques which consist of using liquid polymers as implants to exclude aneurysms from arterial circulation would certainly benefit from this precise measurement of the volume of aneurysms.     

Detection of unruptured familial intracranial aneurysms by intravenous digital subtraction angiography

Summary The authors discuss the detection of intracranial aneurysms (IA) by means of intravenous digital angiography (ivDSA) in (a)symptomatic first degree relatives of families in which two or more individuals have IA. ivDSA is an almost noninvasive and low-risk diagnostic procedure. Screening, by means of ivDSA, of two affected families is described. In family I which includes 7 members with proven IA, ivDSA has been carried out in 36 asymptomatic individuals: in one, a 6x15 mm aneurysm was found at the left posterior communicating artery (PCoA). In family II, including one member with a proven IA and another with a subarachnoid hemorrhage, ivDSA has been carried out in 4 members: one aneurysm with a diameter of 6 mm was found at the left PCoA. Conventional cerebral angiography (CCA) confirmed both IA's. Neurosurgical treatment followed. The advantages and disadvantages of ivDSA vs. CCA as elective screening procedure in such cases are discussed. Screening of asymptomatic first degree relatives of cases with familial IA by means of ivDSA is strongly advocated.     

颅内动脉瘤320排CTA与DSA对照分析

目的 探讨320排CTA对颅内动脉瘤诊断的临床应用价值.方法 收集2010-04-2011-03期间行320排CTA和DSA检查的颅内动脉瘤患者33例.将CTA图像质量按颅底骨质残留及血管显示情况分为4个等级,再以DSA所见为对照,分析320排CTA诊断颅内动脉瘤的敏感性及粗符合率.结果 33例经320排CTA检出颅内动脉瘤30例33个、动静脉畸形(AVM)2例、颅内动脉瘤合并AVM 1例;经DSA证实有颅内动脉瘤30例33个、AVM 3例,其中动脉瘤"假阳性"1例;有22例行手术治疗.320排CTA诊断颅内动脉瘤敏感性为100%,粗符合率为97.0%.结论 与DSA比较,320排CTA诊断颅内动脉瘤有较高的敏感性及粗符合率,在术前筛查方面具有广泛的临床应用前景.     

Evaluation of intracranial aneurysms with high-resolution MR angiography using single-artery highlighting technique: correlation with digital subtraction angiography

Purpose

The authors investigated the effectiveness of high-resolution magnetic resonance angiography (MRA) using a single-artery highlighting technique for the accurate diagnosis of intracranial aneurysms at 3.0 T in a large cohort of patients with suspected intracranial aneurysms against the current gold standard, i.e. cerebral angiography.

Methods

A total of 307 patients with suspected aneurysms were referred for three-dimensional time-of-flight MRA (3D-TOF-MRA) prior to digital subtraction angiography (DSA). We summarised patient-based, aneurysm-based and vessel-based diagnostic performance parameters, namely, accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for detecting intracranial aneurysms with 3D-TOF-MRA. Interobserver agreement was calculated with the kappa (κ) statistic.

Results

Patient-based accuracy was 98.1%, sensitivity 99.5%, specificity 95.3%, PPV 97.6% and NPV 99% according to observer A; and 97.7%, 99.5%, 94.3%, 97.1% and 99%, respectively, according to observer B. Aneurysmbased accuracy was 98.3%, sensitivity 99.6%, specificity 95.2%, PPV 98.1% and NPV 99% according to observer A, and 98.0%, 99.6%, 94.3%, 97.7% and 99%, respectively, according to observer B. Vessel-based accuracy was 99.0%, sensitivity 99.6%, specificity 98.7%, PPV 97.8%, and NPV 99.7% according to observer A, and 98.9%, 99.6%, 98.5%, 97.3%, and 99.7%, respectively, according to observer B. Interobserver reading differences were not significant. The interobserver agreement was good, with a kappa (κ) value of 0.931 for patient-based evaluation, 0.934 for aneurysmbased evaluation and 0.953 for vessel-based evaluation.

Conclusions

Our results demonstrate the effectiveness of high-resolution MRA using a single-artery-highlighting technique for accurate diagnosis of intracranial aneurysms in a large cohort of patients with suspected aneurysms.     

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。     

Diagnostic accuracy of CT angiography with matched mask bone elimination for detection of intracranial aneurysms: comparison with digital subtraction angiography and 3D rotational angiography

BACKGROUND AND PURPOSE: Our aim was to determine the diagnostic accuracy of multisection CT angiography combined with matched mask bone elimination (CTA-MMBE) for detection of intracranial aneurysms compared with digital subtraction angiography (DSA) and 3D rotational angiography (3DRA).MATERIALS AND METHODS: Between January 2004 and February 2006, 108 patients who presented with clinically suspected subarachnoid hemorrhage underwent both CTA-MMBE and DSA for diagnosis of an intracranial aneurysm. Two neuroradiologists, independently, evaluated 27 predefined vessel locations in the CTA-MMBE images for the presence of an aneurysm. After consensus, diagnostic accuracy of CTA was calculated per predefined location and per patient. Interobserver agreement was calculated with κ statistics.RESULTS: In 88 patients (81%), 117 aneurysms (82 ruptured, 35 unruptured) were present on DSA. CTA-MMBE detected all ruptured aneurysms except 1. Overall specificity, sensitivity, positive predictive value, and negative predictive value of CTA-MMBE were 0.99, 0.90, 0.98, and 0.95 per patient and 0.91, 1.00, 0.97, and 0.99 per location, respectively. Sensitivity was 0.99 for aneurysms ≥3 mm and 0.38 for aneurysms <3 mm. Interobserver agreement for aneurysm detection was excellent (κ value of 0.92 per location and 0.80 per patient).CONCLUSION: CTA-MMBE is accurate in detecting intracranial aneurysms in any projection without overprojecting bone. CTA-MMBE has limited sensitivity in detecting very small aneurysms. Our data suggest that DSA and 3DRA can be limited to the vessel harboring the ruptured aneurysm before endovascular treatment, after detection of a ruptured aneurysm with CTA.

In current clinical practice, CT angiography (CTA) is the most frequently used noninvasive diagnostic tool for detection of intracranial aneurysms in the acute setting.^1–8 However, detection of intracranial aneurysms by CTA is limited because axial source section evaluation is tedious and 3D visualization is hampered by overprojecting bone, especially in the region of the skull base.^2,9–13 Several methods to remove bone, such as subtraction and manual or automated bone editing, have been developed.^7,8,14–19 Drawbacks of these methods are the complexity of use, dependence on the user, or high dose of radiation.Matched mask bone elimination (MMBE) is a relatively new technique to remove bone from CTA source images (CTA-MMBE) in an automatic and user-independent way with little additional radiation dose.^20–22 In CTA-MMBE, a second nonenhanced low-dose scan (about a quarter of the radiation dose of a regular CTA) is used to identify bony structures that can subsequently be masked in the CTA scan.Digital subtraction angiography (DSA) is the gold standard for detection of intracranial aneurysms. Extension of DSA with 3D rotational angiography (3DRA) can further improve detection of intracranial aneurysms that may be obscured by overprojecting vessels.^23–25 The advantages of DSA over CTA are superior spatial and contrast resolution, no interference of bony structures, and the possibility to perform direct endovascular interventions.^26,27 However, DSA is an invasive technique with a small but significant risk of neurologic complications, estimated to occur in 0.3%–1.8% of patients.^28,29The purpose of this study was to determine the diagnostic accuracy of CTA-MMBE for detection of intracranial aneurysms in a large patient population with clinically suspected subarachnoid hemorrhage (SAH) with DSA and 3DRA as reference standards.     

Detection and characterization of intracranial aneurysms with 16-channel multidetector row CT angiography: a prospective comparison of volume-rendered images and digital subtraction angiography

BACKGROUND AND PURPOSE: The aim of our study was to compare multidetector row CT angiography (MDCTA) with digital subtraction angiography (DSA) in the detection and characterization of intracranial aneurysms. MATERIALS AND METHODS: In our blinded prospective study, 85 patients with suspected intracranial aneurysm (47 women, 38 men; age range, 19-83 years) underwent both 16-channel MDCTA and DSA. The MDCT angiograms were interpreted for the presence, location, size, ratio of the neck to the dome (N/D ratio), and lobularity of the aneurysms and relationship of the aneurysm with the adjacent arterial branches, by using volume-rendering techniques. MDCTA and DSA images (reference standard) were interpreted by 2 independent readers, and the results were compared. RESULTS: A total of 93 aneurysms were detected at DSA in 71 patients, whereas no aneurysms were detected in 14 patients. Compared with DSA, the overall sensitivity, specificity, and accuracy of MDCTA on a per-aneurysm basis were 92.5%, 93.3%, and 92.6%, respectively, for both independent readers. For aneurysms of <3 mm, however, MDCTA had a sensitivity of 74.1% for reader 1 and 77.8% for reader 2. There was excellent agreement between readers in the detection of aneurysms (kappa = 0.822). In addition, MDCTA was also accurate in determining N/D ratio of aneurysms, aneurysm lobularity, and adjacent arterial branches. CONCLUSION: MDCTA is accurate in the detection and characterization of intracranial aneurysms and can be used as a reliable alternative imaging technique to DSA in selected cases.     

Spiral CT angiography and selective digital subtraction angiography of internal carotid artery stenosis.

PURPOSETo determine whether spiral CT angiography allows accurate, quantitative evaluation of anatomic abnormalities, including detection of additional lesions, delineation of plaque morphology, and estimation of degree of internal carotid artery stenosis.METHODSSpiral CT angiography with a maximum intensity projection technique was compared with selective digital subtraction angiography (DSA) in 92 carotid arteries. The category of stenosis was determined according to the North American Symptomatic Carotid Endarterectomy Trial: mild (0% to 29%), moderate (30% to 69%), severe (70% to 99%), and occlusion (100%).RESULTSIn 78 (85%) of the 92 cases, spiral CT angiography and selective DSA demonstrated the same degree of stenosis. All occlusions (n = 19) were diagnosed correctly with spiral CT angiography. Spiral CT angiography agreed with selective DSA in the classification of stenosis in 59% of the group with mild stenosis, in 82% of the group with moderate stenosis, and in 90% of the group with severe stenosis. In the groups with mild (n = 13), moderate (n = 9), and severe (n = 27) stenosis, correlation of spiral CT angiography with selective DSA was significant. Calcified plaques were readily diagnosed with the use of spiral CT angiography but delineation of ulcers was poor. Tandem lesions were not visible owing to the limited coverage.CONCLUSIONSpiral CT angiography is useful for the detection of proximal internal carotid stenoses that are greater than 30%. Depiction of mild stenoses appears to be limited. CT is superior for the detection of calcified plaques but it is not useful for the detection of ulcers.     

旋转式三维数字减影血管造影在脑动脉瘤临床诊断和治疗中的应用价值

目的：探讨旋转式三维数字减影血管造影在脑动脉瘤诊断和治疗中的应用价值，提高诊断水平，增强治疗效果。方法：回顾性分析了213例脑动脉瘤患者的二维、三维数字减影脑血管造影的影像学资料，并对其结果进行了对比分析。结果：213例患者中共检出222枚脑动脉瘤，其中囊性动脉瘤197枚，梭形动脉瘤16枚，夹层动脉瘤9枚；在222枚脑动脉瘤中，小型动脉瘤105枚，中型动脉瘤89枚，大型动脉瘤22枚，巨大型动脉瘤6枚。常规DSA清楚显示的有205枚，17枚显示可疑由三维数字减影脑血管造影进一步证实；对138例脑动脉瘤患者进行手术开颅银夹夹闭治疗，19例进行介入性金属微弹簧圈栓塞治疗。结论：旋转式三维脑血管造影可有效提高脑动脉瘤的诊断准确性和多种治疗方法的安全十牛及疗效。     

Three-dimensional reconstructed rotational digital subtraction angiography in planning treatment of intracranial aneurysms

We evaluated three-dimensional (3D) reconstructions of 200 ° rotational digital subtraction angiography (DSA) images for their contributions to improving the safety of endovascular embolization of intracranial aneurysms. Standard DSA and 200 ° rotational DSA were performed in 40 adult patients (aged 21–77 years) with 45 intracranial aneurysms. Information obtainable from standard DSA and 3D-DSA images about aneurysm shape and size was compared. In 40 (89 %) of the 45 aneurysms 3D-DSA gave additional information about the anatomy of the aneurysm. In 17 (43 %) of these cases aneurysm anatomy could be visualized better on 3D-DSA than on standard DSA images. In three cases only 3D-DSA images showed blood vessels originating from the aneurysm. Reconstructed 3D images were also helpful in visualizing partially clipped aneurysms. On maximum-intensity projection images it was even possible to depict previously embolized aneurysms. Blood vessels originating from the aneurysm are visible on 3D-DSA images, and even previously clipped aneurysms can be visualized well. Rotational DSA with 3D reconstruction is a helpful tool in the assessment of intracranial aneurysms. Received: 7 September 1999; Revised: 26 November 1999; Accepted: 26 November 1999