Follow-up of intracranial aneurysms treated with detachable coils: comparison of 3D inflow MRA at 3T and 1.5T and contrast-enhanced MRA at 3T with DSA

Introduction  The purpose of this prospective study was to compare 3T and 1.5T magnetic resonance angiography (MRA) with digital subtraction angiography (DSA) for the follow-up of endovascular treated intracranial aneurysms to assess the grade of occlusion. Materials and methods  Thirty-seven patients with 41 aneurysms who had undergone endovascular treatment with detachable coils were included. MRA was performed on the same day using an eight-channel sensitivity encoding head-coil with 3D axial inflow technique. At 3T, a contrast-enhanced transverse 3D fast gradient echo acquisition was also performed. Most patients underwent DSA the following day. MRA scans and DSA were classified first independently by two neuroradiologists and an interventional neuroradiologist. Secondly, a consensus was done. Source images, maximum intensity projection, multiplanar reconstruction and volume rendering reconstructions were used for MRA evaluations. A modification of the Raymond classification, previously used for DSA evaluation of recanalization, was used. Results  Statistical comparison of the consensus showed that 3T MRA with 3D axial inflow technique had better agreement with DSA (κ = 0.43) than 1.5T MRA(κ = 0.21) and contrast-enhanced MRA (CE-MRA) at 3T (κ = 0.17). The susceptibility artefacts from the coil mesh were significally smaller at 3T (p = 0.002–0.007) than at 1.5T. Conclusion  3T MRA, using a sensitivity encoding head-coil, showed better agreement with DSA than 1.5T and CE-MRA at 3T for evaluation of aneurysms treated with endovascular coiling.     

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.     

Is digital substraction angiography still needed for the follow-up of intracranial aneurysms treated by embolisation with detachable coils?

Introduction  Follow-up of intracranial aneurysms treated by embolisation with detachable coils is mandatory to detect a possible recanalisation. The aim of this study was to compare contrast-enhanced magnetic resonance angiography (CE-MRA) with digital substraction angiography (DSA) used to detect aneurysm recanalisation to determine if DSA is still needed during follow-up. Materials and methods  From May 2006 to May 2007, 55 patients with 67 aneurysms were treated by endosaccular coiling with (n = 9) or without (n = 58) an adjunctive stent. Follow-up imaging protocol included MRA at 6 and 12 months and a DSA at 12 months or earlier if a major recanalisation was identified on the 6-month MRA. Two neuroradiologists independently reviewed MRA images (readers 1 and 2) and two other reviewed DSA images. Results  Follow-up DSA showed stability of the aneurysm occlusion in 52 cases, recanalisation in 14 cases, and further thrombosis in one. On CE-MRA, both readers identified all recanalisations but one (sensitivity of 93%) as they missed a major recanalisation in a 2-mm ruptured aneurysm. There were two false-positive evaluations by reader 1 and three for reader 2. Mean specificity of CE-MRA to detect aneurysm recanalisation was 95.5%. Conclusion  CE-MRA is accurate to detect aneurysm recanalisation after embolisation with detachable coils. CE-MRA may be proposed as first-intention imaging technique for their follow-up. However, its sensitivity and specificity remain inferior to that of DSA and major recurrences may be missed in very small aneurysms. Therefore, a single DSA remains mandatory during the imaging follow-up.     

Follow-up of intracranial aneurysms treated with detachable coils: comparison of gadolinium-enhanced 3D time-of-flight MR angiography and digital subtraction angiography

PURPOSE: To compare three-dimensional (3D) time-of-flight magnetic resonance (MR) angiography with digital subtraction angiography (DSA) in the follow-up of intracranial aneurysms treated with selective endovascular placement of detachable coils. MATERIALS AND METHODS: Sixty-eight consecutive patients with intracranial aneurysms were included in the prospective study. The goal was to evaluate 3D time-of-flight MR angiography versus DSA for the detection of a residual aneurysm neck or residual flow inside the coil mesh. RESULTS: Eighty-one MR angiographic and 83 DSA examinations were performed; 15 patients were examined with both modalities twice. MR angiography was not possible in two patients. In another patient, the quality of MR angiography was not sufficient to assess the treated aneurysm. In 72 of the remaining 80 MR angiographic and DSA examinations, there was good correlation between the two modalities. In 54 cases, neither image type showed remnants or recurrence, but in 18, both showed residual aneurysm. In eight cases, the MR angiographic and DSA results differed. In one of these cases, MR angiography depicted residual aneurysm but DSA depicted an arterial loop. In seven cases, a small (<3-mm) remnant was not detected at MR angiography. CONCLUSION: Because very small aneurysm remnants or recurrences probably are not clinically important, MR angiography is an option for following up intracranial aneurysms treated with detachable coils and may partly replace DSA.     

3.0T时间飞跃法MRA诊断颅内动脉瘤-与DSA对照

目的评价3.0T时间飞跃法磁共振血管成像(3.0TTOFMRA)对颅内动脉瘤的诊断价值。方法对34例临床提示颅内动脉瘤患者前瞻性行3.0TTOFMRA及脑血管DSA检查。所有图像由3名医师分成2组在工作站上进行读片。第1组由2名高年资神经影像组医师分别独立阅读重建的最大密度投影(MIP)图像;第2组由1名高年资神经影像组医师同时阅读MIP和原始数据图像(sourceimage)。以DSA诊断结果作为标准,评价3.0TTOFMRA诊断颅内动脉瘤的灵敏度、特异度及正确率。结果DSA共检测20枚动脉瘤(19例),其中颈内动脉7例,前交通动脉5例,后交通动脉5例,大脑前、中动脉各1例。TOFMRA总体诊断灵敏度、特异度、正确率分别为94.8%、89.4%和91.4%。第2组的诊断有效性最高,两组间诊断阳性率差异无统计学意义(χ2=0.242,P>0.05和χ2=0.172,P>0.05)。结论3.0TTOFMRA作为一种快速、无创的影像检查方法,能够很好显示颅内动脉瘤。MIP结合Source图像可提高3.0TTOFMRA诊断的准确性。     

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     

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。     

MR angiography in the follow-up of intracranial aneurysms treated with Guglielmi detachable coils: systematic review and meta-analysis

Introduction The aim of this study was to systematically review published data on the diagnostic performance of magnetic resonance angiography (MRA) compared with digital subtraction angiography as reference standard in the follow-up of intracranial aneurysms treated with Guglielmi detachable coils. Methods A systematic search for relevant studies was performed of the PubMed/MEDLINE and Embase databases. Two reviewers independently assessed the methodological quality of each study. A meta-analysis of the reported sensitivity and specificity of each study was performed. Results The inclusion criteria were met by 16 studies. The studies had moderate methodological quality. Pooled sensitivity and specificity of nonenhanced time-of-flight MRA (TOF-MRA) for the detection of residual flow (within the aneurysmal neck and/or coil mesh) were 83.3% (95% CI 70.3–91.3%) and 90.6% (95% CI 80.4–95.8%), respectively. Pooled sensitivity and specificity of contrast-enhanced MRA (CE-MRA) for the detection of residual flow were 86.8% (95% CI 71.4–94.5%) and 91.9% (95% CI 79.8–97.0%), respectively. All pooled estimates were subject to heterogeneity. There were no statistically significant differences in pooled sensitivity and specificity between TOF-MRA and CE-MRA. Conclusion The results of this study suggest that both TOF-MRA and CE-MRA achieve a moderate to high diagnostic performance. However, the findings should be interpreted with caution because the included studies were of moderate methodological quality and all pooled estimates were subject to heterogeneity. More well-designed studies are required to confirm the current results and MRA at higher field strength (>1.5 T) needs to be further explored.     

Three-dimensional volume rendering digital subtraction angiography in comparison with two-dimensional digital subtraction angiography and rotational angiography for detecting aneurysms and their morphological properties in patients with subarachnoid hemorrhage

Objective

Subarachnoid hemorrhage (SAH), which can cause mortality and severe morbidity, is a serious condition whose underlying cause must be determined. We aimed to compare 2D digital subtraction angiography (2DDSA), rotational angiography (RA) and 3D volume rendering digital subtraction angiography (3DVRDSA) for detecting aneurysms and their morphological properties in patients with subarachnoid hemorrhage.

Materials and methods

After an initial diagnosis of SAH with computed tomography, 122 patients (52 males and 70 females with a mean age of 47.77 ± 12.81 ranging between 20 and 83 years) underwent 2DDSA imaging, RA and 3DVRDSA imaging for detection of aneurysms. The location of the aneurysm, the best working angles, the dome/neck ratios, the largest diameter of the aneurysm, the shape of the aneurysm, the presence of spasms or pseudostenoses, and the relationship to the neighboring arteries were recorded.

Results

2DDSA missed 15.6% of the aneurysms that had a mean size of 2.79 ± 0.74 mm. RA was superior to 2DDSA for detecting aneurysm neck, and 3DVRDSA was superior to RA for detecting aneurysm neck. 3DVRDSA conclusively depicted the shape of the aneurysms in all patients. 3DVRDSA imaging was superior to 2DDSA and RA in the detection of the aneurysm relationship to neighboring arteries. The sensitivity and specificity of 3DVRDSA imaging for the detection of vasospasms were 100 and 84%, respectively.

Conclusions

3DVRDSA imaging is superior to 2DDSA and RA for detecting intracranial aneurysms and their morphological properties, especially those of small, ruptured aneurysms. However, 2DDSA should not be neglected in cases of vasospasm.     

Three-dimensional time-of-flight MR angiography for evaluation of intracranial aneurysms after endosaccular packing with Guglielmi detachable coils: comparison with 3D digital subtraction angiography

The sensitivities and specificities of three-dimensional time-of-flight MR angiography (3D-TOF MRA) and 3D digital subtraction angiography (3D-DSA) were compared for evaluation of cerebral aneurysms after endosaccular packing with Guglielmi detachable coils (GDCs). Thirty-three patients with 33 aneurysms were included in this prospective study. 3D-TOF MRA and 3D-DSA were performed in the same week on all patients. Maximal intensity projection (MIP) and 3D reconstructed MRA images were compared with 3D-DSA images. The diameters of residual/recurrent aneurysms detected on 3D-DSA were calculated on a workstation. In 3 (9%) of 33 aneurysms, 3D-TOF MRA did not provide reliable information due to significant susceptibility artifacts on MRA. The sensitivity and specificity rates of MRA were 72.7 and 90.9%, respectively, for the diagnosis of residual/recurrent aneurysm. The diameters of residual/recurrent aneurysms that could not be detected by MRA were significantly smaller than those of detected aneurysms (mean 1.1 vs mean 2.3 mm). In one aneurysm of the anterior communicating artery (ACoA), the relationship between the residual aneurysm and the ACoA was more evident on MRA than DSA images. MRA can detect the recurrent/residual lumen of aneurysms treated with GDCs of up to at least 1.8 mm in diameter. 3D-TOF MRA is useful for follow-up of intracranial aneurysms treated with GDCs, and could partly replace DSA.     

Subtraction CT angiography for evaluation of intracranial aneurysms: comparison with conventional CT angiography

The purpose of our study was to compare the diagnostic performance of subtraction computed tomography angiography (CTA) with conventional nonsubtracted CTA and digital subtraction angiography (DSA) for the detection of intracranial aneurysms. A total of 76 patients underwent both subtraction CTA and conventional CTA for the detection and therapy planning of suspected intracranial aneurysms. Subtraction and conventional CTA images were independently assessed by two readers in a blinded manner. The possibility of endovascular treatment or surgical clipping was also assessed based on information provided by CT angiograms alone. In 64 patients, 75 aneurysms were present on DSA. On a per-aneurysm basis, the sensitivity of subtraction CTA was 98.6% for reader 1, and 100% for reader 2. However, sensitivity of conventional CTA was 94.6% for reader 1, and 93.3% for reader 2. Therapeutic decisions could be made regarding 63 patients based on information provided by subtraction CTA images. However, conventional CTA provided sufficient information to make this decision for 55 patients. Conventional CTA has limited sensitivity in detecting very small aneurysms as well as aneurysms adjacent to bone. Subtraction CTA performed on a 64-row multidetector CT is an accurate and promising diagnostic tool that seems to be equivalent to 2D DSA for the detection and pretreatment planning of intracranial aneurysms.     

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%.     

三维DSA容积重建在颅内小动脉瘤中的诊断价值

目的：评价三维数字减影血管造影（DSA）容积重建在颅内小动脉瘤的诊断价值。方法对129例可疑颅内动脉瘤患者在行弹簧圈栓塞前进行二维DSA和三维容积重建-数字减影血管造影（VR-DSA）检查。结果三维VR-DSA显示105例患者有123枚动脉瘤,24例无动脉瘤。3例患者检测到3枚动脉瘤;12例患者同时检测到2枚动脉瘤;90例患者检测到1枚动脉瘤。所有的动脉瘤的形态在三维VR-DSA上均可清晰显示。二维DSA显示98例患者有110枚动脉瘤,31例无动脉瘤。1例患者检测到3枚动脉瘤;10例患者同时检测到2枚动脉瘤;87例患者检测到1枚动脉瘤。仅65例患者的动脉瘤的形态在二维DSA上可清晰显示。三维VR-DSA发现13例额外动脉瘤,位于颈内动脉（10例,77％）,位于前交通动脉（3例,33％）。大脑中动脉与椎基底动脉未发现额外动脉瘤。结论三维容积DSA不仅能清晰显示动脉瘤的大小及形态,而且能检测出二维DSA未检出的动脉瘤,特别是微小动脉瘤。     

Detection of intracranial aneurysms with multislice CT: comparison with conventional angiography

We assessed the diagnostic accuracy of multislice CT in detection of intracranial aneurysms in patients presenting with subarachnoid or intracranial haemorrhage. Multislice CT and multiplanar digital subtraction angiography (DSA) images were obtained in 50 consecutive patients presenting with subarachnoid (SAH) and/or intracranial haemorrhage and reviewed by three neuroradiologists for the number, size and site of any aneurysms. The CT data were assessed using multiplanar reformats (MPR), maximum-intensity projections (MIP), surface-shaded display (SSD) and volume-rendering (VRT). In conventional angiography 51 aneurysms were detected in 41 patients. CT angiography (CTA) showed up to 48 aneurysms in 39 patients, depending on the observer. The overall sensitivity of multislice CT was 83.3% for small (<4 mm), 90.6% for medium-size (5–12 mm) and 100% for large (>13 mm) aneurysms. The sensitivity of multislice CTA to medium-size and large intracranial aneurysm is within the upper part of the range reported for helical single-slice CT. However, as small aneurysms may not be found, DSA remains the standard technique for investigation of SAH.     

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     

Three-dimensional time-of-flight (3D TOF) magnetic resonance angiography (MRA) and contrast-enhanced MRA of intracranial aneurysms treated with platinum coils

Background: Contrast-enhanced magnetic resonance angiography (CE-MRA) is less prone to flow-related signal intensity loss than three-dimensional time-of-flight (3D TOF) MRA and may therefore be more sensitive for detection of residual patency in platinum coil-treated intracranial aneurysms.

Purpose: To compare MRA and CE-MRA in the follow-up of intracranial aneurysms treated with platinum coils.

Material and Methods: CE-MRA and 3D TOF MRA (pre- and postcontrast injection) of the intracranial vasculature was performed at 1.5T in 38 patients (47 aneurysms) referred for DSA in the follow-up of coiled intracranial aneurysms.

Results: DSA showed aneurysm patency in 22/47 investigations. Patent aneurysm components were observed with CE-MRA in 18/22 cases, and with 3D TOF MRA in 21/22 cases. There was no significant difference in patent aneurysm component size between CE-MRA and 3D TOF MRA. In addition, CE-MRA showed six, 3D TOF MRA before contrast injection showed seven, and 3D TOF MRA after contrast injection showed eight cases with patent aneurysm components not observed on DSA.

Conclusion: 3D TOF MRA was highly sensitive for detection of patent aneurysm components, and at least as sensitive as CE-MRA. Residual aneurysm patency seems to be better visualized with MRA than with DSA in some cases.     

Intracranial aneurysms: evaluation using CTA and MRA. Correlation with DSA and intraoperative findings

Computed tomographic angiography (CTA) and magnetic resonance angiography (MSA) have been used recently for evaluation of intracranial aneurysms. If they are to replace conventional digital subtraction angiography (DSA), their sensitivity and specificity should be equal to the latter. In order to determine whether computed tomographic angiography and magnetic resonance angiography can provide the necessary information for presurgical evaluation we compared blindly the results of helical CT angiography and MR angiography with the results of digital subtraction angiography and the intraoperative findings. We evaluated 35 patients with the possible clinical diagnosis of intracranial aneurysm. Our data suggest that both CTA and MRA can provide valuable preoperative information concerning the location, the characteristics and the relationships of most intracranial aneurysms. Both original and reconstructed images should be evaluated together for higher accuracy. In addition helical CT, being a fast, inexpensive and noninvasive method, can be used as a reliable alternative to DSA in emergency situations demanding immediate operation.     

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。     

Persistent hypoglossal artery: MRI, MRA and digital subtraction angiography

We present the MRI, MRA and digital subtraction angiography (DSA) findings in a persistent hypoglossal artery found incidentally in a patient with cutaneous and intracranial haemangiomata. Received: 20 September 2000/Accepted: 21 November 2000     

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。