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.     

MR angiography with three-dimensional time-of-flight and targeted maximum-intensity-projection reconstructions in the follow-up of intracranial aneurysms embolized with Guglielmi detachable coils.

BACKGROUND AND PURPOSE: Intra-arterial contrast angiographies are generally used to confirm treatment results of endovascular neurointerventions such as aneurysm obliteration. We compared MR angiography with digital subtraction angiography (DSA) as a follow-up technique for the detection of aneurysmal remnant cavities and arterial patency in patients treated for intracranial aneurysms with Guglielmi detachable coils (GDCs). METHODS: In 20 consecutive patients, follow-up MR angiography and routine intra-arterial cerebral angiography were performed on the same day 1 to 7 months (mean, 4.5 months) after embolization with GDCs. MR angiographic data were postprocessed for subvolume maximum intensity projections centered on the region of the treated aneurysm. Hard copies of both imaging studies were interpreted independently in a blinded fashion to record and compare remnant cavities, location of residual flow, and adjacent arterial narrowing, using DSA as the standard of reference. The interpreters also established an occlusion grade for the treated aneurysms as evidenced on DSA images and evaluated MR angiograms for artifactual effects. RESULTS: Overall sensitivity and positive predictive value of MR angiography in revealing aneurysmal remnant cavities were both 90%. Specificity in ruling out a remnant cavity with MR angiography was 91%. One remnant cavity was missed by MR angiography, and in five patients, false adjacent arterial encroachments were reported. CONCLUSION: MR angiography may be useful in the long-term follow-up of successfully treated small and medium-sized aneurysms after concurrent primary verification of their occlusion with DSA.     

Diagnostic accuracy of 3D time-of-flight MR angiography compared with digital subtraction angiography for follow-up of coiled intracranial aneurysms: influence of aneurysm size

BACKGROUND AND PURPOSE: 3D time-of-flight MR angiography (3D TOF MRA) may be used as noninvasive alternative to digital subtraction angiography (DSA) for the follow-up of patients with intracranial aneurysms treated with Guglielmi detachable coils (GDCs). We aimed to determine the influence of aneurysm size and location on diagnostic accuracy of 3D TOF MRA for follow-up of intracranial aneurysms treated with GDCs. MATERIALS AND METHODS: Two hundred and one 3D TOF MRAs in 127 consecutive patients with 136 aneurysms were compared with DSA as standard of reference. Sensitivity and specificity of 3D TOF MRA for detection of residual or reperfusion of the aneurysms was calculated with regard to aneurysm size and location. RESULTS: Overall sensitivity and specificity of MRA was 88.5% and 92.9%, respectively. Sensitivity was lower for aneurysms 相似文献   

MR angiography of saccular aneurysms after treatment with Guglielmi detachable coils: preliminary experience.

PURPOSETo review our experience using MR angiography to assess the cerebral vasculature after aneurysmal treatment with Guglielmi detachable coils (GDCs).METHODSForty three-dimensional time-of-flight MR angiographic studies were performed in 23 patients after endovascular aneurysmal therapy with GDCs. Digital subtraction angiographic (DSA) studies were evaluated retrospectively for the following findings: parent artery patency, branch vessel patency, residual flow within the aneurysm, and residual aneurysmal neck. The MR angiographic examinations were inspected for the same findings, as well as for the degree of signal loss surrounding the coil mass. Clinical histories were reviewed to determine the impact of MR angiographic findings on therapy.RESULTSPatency status of the parent artery was correctly identified on 25 of 26 MR angiographic examinations with DSA confirmation. Thirty-four of 37 patent branch vessels were identified by MR angiography. Residual neck was correctly identified in seven studies of six aneurysms, with no false-negative or false-positive results. Intraaneurysmal flow was correctly identified in five of eight studies of six aneurysms with residual flow shown by DSA. Artifact and hemorrhage mimicked residual flow in two of 18 MR angiographic studies of aneurysms with no residual flow shown by DSA. In eight patients, MR angiography provided clinically useful information that affected therapy.CONCLUSIONSMR angiography can identify flow within an aneurysm after treatment with GDCs as well as in the adjacent parent and branch vessels. This technique may be a useful adjunct to DSA in some clinical situations.     

Utility of CT angiography and MR angiography for the follow-up of experimental aneurysms treated with stents or Guglielmi detachable coils

BACKGROUND AND PURPOSE: Previous studies have depicted arterial and aneurysmal anatomy with three-dimensional time-of-flight (3D-TOF) MR angiography before and after treatment with Guglielmi detachable coils (GDCs) and with CT angiography before and after treatment with stents and stent-grafts. We investigated the ability of time-resolved contrast-enhanced 3D MR angiography (3D MR digital subtraction angiography [DSA]) to accurately depict the anatomy of experimental lateral aneurysms before and after treatment with GDCs and a variety of stents or stent-grafts, and compared these findings with 3D-TOF MR angiography without and with contrast enhancement and CT angiography. METHODS: Two nitinol stents, two nitinol-polytetrafluoroethylene (PTFE) stent-grafts, and two stainless steel stents were deployed in three dogs with experimental carotid aneurysms. In a fourth animal, one of three aneurysms was completely occluded with GDCs. The other two aneurysms were loosely packed to ensure persistence of some residual aneurysmal lumen. Cut-film angiography, CT angiography, 3D-TOF MR angiography without and with contrast enhancement, and 3D MR DSA were performed in all dogs before and 3 weeks after treatment. RESULTS: 3D MR DSA was superior to conventional 3D-TOF MR angiography without and with contrast enhancement in accurately depicting experimental lateral aneurysms and superior to CT angiography in depicting aneurysms treated by GDCs. 3D MR DSA and CT angiography were comparable in depicting vessels treated with nitinol stents and stent-grafts, whereas CT angiography was superior for showing vessels treated by stainless steel stents. CONCLUSION: We recommend further development and clinical evaluation of 3D MR DSA for imaging cerebral aneurysms before and after treatment with GDCs. 3D MR DSA or CT angiography may be useful for evaluating vessels containing nitinol stents or nitinol-PTFE stent-grafts, whereas CT angiography should be used for follow-up of vessels treated by stainless steel stents.     

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.     

MR angiography at 3T versus digital subtraction angiography in the follow-up of intracranial aneurysms treated with detachable coils

BACKGROUND AND PURPOSE: Digital subtraction angiography (DSA) is used to follow-up intracranial aneurysms treated with detachable coils to identify recurrence and determine need for additional treatment. However, DSA is invasive and involves a small risk of neurologic complications. We assessed the feasibility and usefulness of 3D time-of-flight (TOF) MR angiography (MRA) performed at 3T compared with DSA for the follow-up of coil-treated intracranial aneurysms. METHODS: In a prospective study, 20 consecutive patients with 21 intracranial aneurysms treated with coils underwent DSA and nonenhanced and enhanced multiple overlapping thin-slab acquisition 3D TOF MRA at 3T on the same day at a mean follow-up of 6 months (range, 4-14 months) after coil placement. MRA images were evaluated for presence of artifacts, presence and size of aneurysm remnants and recurrences, patency of parent and branch vessels, and added value of contrast material enhancement. MRA and DSA findings were compared. RESULTS: Interobserver agreement of MRA was good, as was agreement between MRA and DSA. All three recurrences that needed additional treatment were detected with MRA. Minor disagreement occurred in four cases: three coil-treated aneurysms were scored on MRA images as having a small remnant, whereas on DSA images these aneurysms were occluded; the other aneurysm was scored on MRA images as having a small remnant, whereas on DSA images this was a small recurrence. Use of contrast material had no additional value. Coil-related MR imaging artifacts were minimal and did not interfere with evaluation of the occlusion status of the aneurysm. CONCLUSION: High-spatial-resolution 3D TOF MRA at 3T is feasible and useful in the follow-up of patients with intracranial aneurysms treated with coil placement.     

MR angiography in the follow-up of coiled cerebral aneurysms after treatment with Guglielmi detachable coils

Purpose: Intra-arterial digital subtraction angiography (DSA) has been considered the gold standard examination in the follow-up of patients treated with Guglielmi detachable coils (GDCs). However, DSA is an invasive and expensive investigation and results in exposure to ionising radiation to both patient and operator. The aim of this study was to compare MR angiography (MRA) with DSA with regard to patency of the occlusion of aneurysms following GDC treatment.Material and Methods: We performed 75 MRA and DSA examinations on 51 patients treated with GDCs. The examinations were performed 3-36 months after embolisation and the interval between MRA and DSA was less than 1 week. Hard copies of both studies were interpreted retrospectively and independently for residual flow within the aneurysm, residual aneurysmal neck, and parent and branch vessel flow.Results: Patency status of parent and branch vessel flow was correctly identified with MRA in all patients except 1. The sensitivity of MRA in revealing residual flow within the aneurysm was 97%. The specificity in ruling out residual flow within the aneurysm was 91%.Conclusion: MRA may replace DSA in the long-term follow-up of coiled cerebral aneurysms. The initial follow-up examination should, however, include both modalities.     

Aneurysms of the anterior communicating artery treated with Guglielmi detachable coils: follow-up with contrast-enhanced MR angiography

BACKGROUND AND PURPOSE: The long-term outcome of patients treated with Guglielmi detachable coils (GDCs) remains unknown and is being evaluated. We sought to assess the feasibility and utility of contrast-enhanced MR angiography in the follow-up of anterior communicating artery (AcomA) aneurysms treated with GDCs. METHODS: In a prospective study, 20 consecutive patients with AcomA aneurysms underwent digital subtraction angiography (DSA), time-of-flight MR angiography (TOF-MRA), and contrast-enhanced MR angiography (MRA) 12 months after treatment with GDCs. The aneurysmal sac measured less than 10 mm in 19 patients and 12 mm in one patient. Two observers who did not analyze the DSA images independently reviewed the MRA images. Aneurysms were classified according to the presence of a residual neck (ie, complete occlusion, small residual neck, large residual neck, or not assessable). DSA was used as the standard of reference. RESULTS: Images from all examinations were assessable. Venous enhancement was observed in five cases at contrast-enhanced MRA; this did not affect image interpretation. Interobserver agreement was good. A comparison of the techniques showed good agreement in the detection of a residual neck. Two cases of a small residual neck were not detected at TOF-MRA, and one case of complete occlusion was misclassified as a small residual neck at contrast-enhanced MRA. CONCLUSION: Our findings showed that contrast-enhanced MRA is a valuable method for the follow-up of aneurysms in the AcomA after their treatment with GDCs. Further studies with multiple aneurysm locations and larger groups are required to determine the exact role of this technique.     

Transcranial color-coded Doppler sonography of intracranial aneurysms before and after endovascular occlusion with Guglielmi detachable coils.

BACKGROUND AND PURPOSEOur purpose was to evaluate the ability of transcranial color-coded Doppler sonography (TCCD) to 1) identify Guglielmi detachable coils (GDCs) within intracranial aneurysms, 2) show endovascular aneurysmal occlusion and patency of parent and branch arteries, 3) determine the flow velocities within parent arteries and major branches before and after treatment, and 4) assess persistence of aneurysmal occlusion.METHODSThe sonographic appearance of GDCs was established experimentally by TCCD (2 to 2.5 MHz), which was then performed in 40 patients with 43 aneurysms occluded by GDCs. The patency of parent arteries and major branches was assessed qualitatively and compared with the immediate posttherapeutic angiographic appearance in every patient. Flow velocities were selectively measured and compared before and after treatment in 21 parent arteries and 24 major branches. Follow-up TCCD studies performed in 26 patients were compared with angiographic (16 cases) and MR angiographic (10 cases) findings for signs of recanalization of the treated aneurysms.RESULTSThe GDCs were identified experimentally and in the patients as hyperechoic structures of the size and shape, and in the location of, the treated aneurysm in 41 of 43 cases. TCCD in accordance with angiography showed a lack of flow in 42 aneurysms and the presence of flow signal in one large aneurysm. Patency of the parent artery was shown in 40 aneurysms and in all branches. Follow-up TCCD showed the coils unchanged in 23 of 26 cases. In three large aneurysms, TCCD indicated recanalization and reappearance of a flow signal separate from the parent artery.CONCLUSIONTCCD is a reliable, noninvasive means to assess parent artery and major branch patency and to reveal a lack of hemodynamic compromise in the vicinity of aneurysms after endovascular therapy. On follow-up examinations, TCCD was able to detect signs of aneurysmal recanalization.     

Time-of-flight MR angiography targeted to coiled intracranial aneurysms is more sensitive to residual flow than is digital subtraction angiography

BACKGROUND AND PURPOSE: For intracranial aneurysms treated with Guglielmi detachable coils, long-term follow-up is mandatory because coil compaction may occur and aneurysms may recur. The purpose of this study was to establish a noninvasive technique to visualize residual flow in coiled aneurysms. METHODS: We designed a 3D time-of-flight (3D-TOF) MR angiography (MRA) technique targeted to depict coiled aneurysms that employed a very short TE (1.54-1.60 ms) and a high spatial resolution (0.3 x 0.3 x 0.3 mm3 with zero-filling) to diminish spin dephasing. To diminish spin saturation, image volume was carefully positioned so that the neck of the targeted aneurysm was within 2 cm of the inflow portion along the stream of blood. Fifty-one MRA images of 39 coiled aneurysms in 39 patients were compared with digital subtraction angiography (DSA) images. DSA and MRA findings were interpolated retrospectively for parent and branch arteries' patency, as well as residual flow in aneurysms. In the latest 11 MR studies, a dark-blood 3D turbo spin-echo sequence was added to MRA to negate the effect high-signal-intensity thrombus. RESULTS: MRA visualized all parent and branch arteries with DSA confirmation. MRA visualized residual flow more frequently (38 studies) than did DSA (25 studies). Residual flow space visualized with MRA was always similar to or larger than that with DSA. The dark-blood sequence completely suppressed intraluminal high signal intensity on MRA images and confirmed that the high signal intensity was not due to thrombus. CONCLUSION: TOF MRA targeted to depict coiled intracranial aneurysms is noninvasive and superior to DSA in visualization of residual flow and, hence, useful for follow-up of coiled aneurysms.     

Prospective evaluation of time-of-flight MR angiography in the follow-up of intracranial saccular aneurysms treated with Guglielmi detachable coils

PURPOSE: The purpose of our study was to prospectively evaluate 3D time-of-flight (TOF) MR angiography (MRA) in the follow-up of 27 intracranial aneurysms treated with Guglielmi detachable coils (GDCs). METHOD: From February 1997 to June 1998, 26 patients with 27 aneurysms were included in this prospective study. Aneurysms were located in the anterior circulation in 23 cases and in the posterior circulation in 4 cases. All patients underwent 3D TOF MRA and digital subtraction angiography (DSA) in the same week within 4 months after aneurysmal treatment with GDCs. No clinical events occurred during the follow-up. We analyzed residual flow within the coil mass and within the aneurysmal neck and the patency of the parent and adjacent arteries on MRA and DSA. MRA analysis was based upon MIPPED and source images. DSA was our gold standard. RESULTS: In all cases, the quality of MRA was good enough to be informative. In aneurysmal analysis, the sensitivity, specificity, positive predictive value, and negative predictive value of MRA were, respectively, 80, 100, 100, and 96% to diagnose residual flow within the coil mass (one false-negative case) and 83, 100, 100, and 95.5% to diagnose residual flow within the aneurysmal neck (one false-negative case). In arterial analysis, sensitivity and positive predictive value of MRA were 89 and 100% to diagnose patency of the parent artery (three false-negative cases) and 83 and 100% to diagnose patency of adjacent arteries (seven false-negative cases). CONCLUSION: In the follow-up of intracranial aneurysms treated with GDCs, 3D TOF MRA could be used as a screening test to select patients that should undergo DSA and thus could improve patient follow-up in terms of risk-benefit.     

Intracranial aneurysms treated with Guglielmi detachable coils: is contrast material necessary in the follow-up with 3D time-of-flight MR angiography?

BACKGROUND AND PURPOSE: Three-dimensional time-of-flight (TOF) MR angiography has been evaluated in the follow-up of intracranial aneurysms treated with Guglielmi detachable coils (GDCs) with good results. Some of the studies used contrast material in addition to the 3D TOF MR technique and others did not. We assessed the usefulness of contrast material with 3D TOF MR angiography by comparing this sequence before and after contrast material injection. METHODS: Fifty-eight patients harboring a total of 71 cerebral aneurysms previously treated with GDCs were included in the prospective study. MR angiography (at 1.5 T) was performed with a 3D TOF sequence before and after injection of gadolinium-based contrast material. Features evaluated were presence and size of a neck remnant, parent and adjacent vessel patency, and venous overlap. Digital subtraction angiography was the standard of reference. RESULTS: Comparison of the techniques showed a good agreement in the detection of residual flow. Six cases of small residual neck were not detected with either the 3D TOF or the contrast-enhanced 3D TOF sequence. In one case of giant aneurysm, the extent of recanalization was more evident after contrast material administration. The use of contrast material did not help to show the parent and adjacent arteries. Venous overlap on contrast-enhanced 3D TOF angiograms did not affect image interpretation. CONCLUSION: In this series, the use of intravenous contrast material did not improve the ability of 3D TOF MR angiography to depict the presence of residual or recurrent aneurysms previously treated with endovascular coiling. In one giant aneurysm, use of intravenous contrast material did result in improved visualization of a residual aneurysm.     

Intracranial aneurysms treated with Guglielmi detachable coils: usefulness of 6-month imaging follow-up with contrast-enhanced MR angiography

BACKGROUND AND PURPOSE: This study was undertaken to assess the utility of contrast-enhanced MR angiography at 6 months after endovascular treatment of intracranial aneurysms with Guglielmi detachable coils. METHODS: Contrast-enhanced MR angiography was performed in 47 patients at 6 and 12 months after endovascular treatment of intracranial aneurysms (48 aneurysms). Digital subtraction angiography (DSA) was used as reference and was performed at 12 months after the treatment in all patients. MR angiographs were analyzed independently by two senior radiologists. DSA and MR angiography findings were assigned into one of three categories: complete obliteration, residual neck, or residual aneurysm. RESULTS: All examinations were assessable. Interobserver agreement was judged as very good for contrast-enhanced MR angiography (kappa=0.96), with one discrepancy between examiners. Comparison between MR angiography at 6 months and DSA at 12 months showed an excellent agreement between techniques (kappa=0.93). Two cases of complete occlusion at DSA were misclassified as a residual neck at 6-month MR angiography. All aneurysm recanalizations at DSA already were detected on MR angiography at 6 months. The size of aneurysm recanalization did not increase between both MR angiographs performed at 6 and 12 months. CONCLUSION: Contrast-enhanced MR angiography after selective embolization of intracranial aneurysm seems to predict properly early aneurysm recanalizations.     

3D-T0F MRA对颅内动脉瘤GDC治疗随访的预期评估

目的：评价磁共振血管成像(MRA)在随访43例病人的45个颅内动脉瘤GDC栓塞后的价值。材料和方法：以数字减影血管造影(DSA)作为诊断的金标准，回顾研究43例病人的45个颅内动脉瘤(前循环34个，后循环11个)MRA检查。所有的病人在GDC栓塞治疗后9个月之内的同一周行DSA和MRA检查，这期间不作处理。分析弹簧圈内残余血流、载瘤动脉和邻近动脉血流，MRA以最大强度投影(MIP)重建和源图像为基础。结果：所有病例中，MRA能提供良好的信息。对于动脉瘤的分析，MRA的敏感性、特征性、阳性预测价值、阴性预测价值，诊断弹簧圈内残余血流分别为87．5％、100％、100％、97％，诊断瘤颈的残余血流分别为90％、100％、100％、97％。对于动脉通畅性分析，MRA的敏感性和阴性预测价值，载瘤动脉分别是90．5％和100％，邻近动脉分别是85．7％和100％。结论：在随访GDC栓塞的动脉瘤中，MRA可以作为一个筛选手段，提高检查效率，减少病人的随访风险。     

3D-SPACE序列结合3D-TOF MR血管成像在颅内动脉瘤支架辅助弹簧圈栓塞术后随访中的应用

目的探讨三维T1加权序列可变反转角度快速自旋回波序列(3D T1-SPACE)结合三维时间飞跃法MR血管成像(3D-TOF MRA)在颅内动脉瘤支架辅助弹簧圈栓塞术后患者随访中的应用价值。方法前瞻性收集2017年12月至2018年10月河南省人民医院收治的25例因颅内动脉瘤接受支架辅助弹簧圈栓塞术的患者,均为宽颈动脉瘤。术后6~10个月所有患者均行3D-TOF MRA、3D T1-SPACE序列MR扫描和DSA检查。分别使用3D-TOF MRA和DSA以Raymond分级法评价瘤腔栓塞情况,使用3D-TOF MRA和3D T1-SPACE序列以4分法评价载瘤动脉支架内管腔显示情况。采用配对设计的Wilcoxon秩和检验比较动脉瘤栓塞程度分级和支架内管腔显示情况。以DSA为金标准,计算3D-TOF MRA评估动脉瘤残留的特异度及准确率。结果术后6~10个月随访,对于动脉瘤闭塞情况,DSA造影显示Raymond 1级23例,2级1例,3级1例;3D-TOF MRA 1级21例,2级3例,3级1例;差异无统计学意义(Z=-0.557,P=0.577),其中有4例患者两种评估方法结果不一致。对于载瘤动脉支架内管腔情况的显示,3D-TOF MRA评分3分14例,2分8例,1分3例;3D T1-SPACE序列25例均为4分,3D T1-SPACE优于3D-TOF MRA(Z=-4.484,P<0.001)。以DSA为金标准,3D-TOF MRA结合原图像评估动脉瘤栓塞情况的特异度为86.9%(20/23),准确率为84.0%(21/25)。结论3.0 T MR 3D T1-SPACE序列可清晰显示支架内管腔,能准确判断支架内血管的通畅情况,3D-TOF MRA可充分评估动脉瘤瘤腔有无残留。将上述两种MRI血管成像技术相结合,可用于动脉瘤支架辅助栓塞术后的随访。     

Follow-up of coiled intracranial aneurysms: comparison of 3D time-of-flight and contrast-enhanced magnetic resonance angiography at 3T in a large, prospective series

Objectives

To compare 3D-TOF magnetic resonance angiography (MRA) and contrast-enhanced MRA (CE-MRA) sequences at 3T in the follow-up of coiled aneurysms with digital subtracted angiography (DSA) as the gold standard.

Methods

DSA, 3D-TOF and CE-MRA were performed in a prospective series of 126 aneurysms in 96 patients (57 female, 39 male; age: 25–75 years, mean: 51.3?±?11.3 years). The quality of aneurysm occlusion was assessed independently and anonymously by a core laboratory.

Results

Using DSA (gold standard technique), total occlusion was depicted in 57 aneurysms (45.2%), neck remnant in 34 aneurysms (27.0%) and aneurysm remnant in 35 aneurysms (27.8%). Sensitivity, specificity, positive predictive value and negative predictive value were very similar with 3D-TOF and CE-MRA. Visibility of coils was much better with 3D-TOF (95.2%) than with CE-MRA (23.0%) (P?P?=?0.012).

Conclusions

In this large prospective series of patients with coiled aneurysms, at 3T 3D-TOF MRA was equivalent to CE-MRA for the evaluation of aneurysm occlusion, but coil visibility was superior at 3D-TOF. Thus the use of 3D-TOF at 3T is recommended for the follow-up of coiled intracranial aneurysms.

Key Points

? Different Magnetic Resonance (MR) imaging techniques are used to evaluate intracranial aneurysms. ? At 3T MR, 3D-TOF and CE-MRA appear equivalent for evaluating coiled aneurysms.. ? Coils are better visualised on 3D-TOF than on CE-MRA. ? Combined analysis of 3D-TOF and CE-MRA does not seem helpful. ? At 3T, 3D-TOF techniques are recommended for monitoring patients with coiled aneurysms.     

Follow-up of intracranial aneurysms treated with detachable coils: comparison of plain radiographs, 3D time-of-flight MRA and digital subtraction angiography

All patients with aneurysms treated with Guglielmi detachable coils (GDC) are undergo angiography to assess long-term stability of aneurysm exclusion or to show recurrence of the aneurysm sac, which may require further treatment. We prospectively compared the plain-film appearance of the coil-mass, 3D time-of-flight MR angiography (TOF MRA) and digital subtraction angiography (DSA) for the detection of aneurysm recanalisation during follow-up. We studied 60 patients with 74 intracranial aneurysms treated with Guglielmi detachable coils. We used the unsubtracted image of the angiograms performed at the completion of any embolisation procedure and at follow-up as the plain radiographs. Recanalisation was considered if loosening, compaction or reorientation of the coil mass was apparent. TOF MRA was performed to assess the presence and size of a neck remnant. DSA was regarded as the definitive investigation. Comparison of the techniques showed good agreement as regards aneurysm recanalisation. MRA was more accurate than plain radiography and could replace DSA for long term follow- up. The initial follow-up examination should, however, include both modalities. In cases of contraindications or limitations to MRA, the interval between follow-up angiographic examinations could be increased if there is no change in the plain-film coil-mass appearances.     

第一代Matrix弹簧圈治疗颅内动脉瘤的安全性及中长期随访结果分析

目的分析第一代Matrix可吸收聚合物涂层弹簧圈(简称Matrix)治疗颅内动脉瘤的安全性,及中、长期随访结果的影响因素。方法回顾性研究,本中心2003年5月至2005年7月75例使用Matrix栓塞颅内动脉瘤患者(79枚动脉瘤)。其中造影复查患者34例(35枚动脉瘤),平均随访时间12.5个月。根据复查结果对年龄、性别、动脉瘤最大径、瘤颈宽度、使用支架辅助、Matrix长度比例进行COX模型分析。结果Matrix相关的手术并发症率为13.3%,使用Matrix术后动脉瘤总复发率为11.4%,辅助支架治疗的大型动脉瘤的复发率为40%,未致密栓塞的动脉瘤中61.1%发生进一步栓塞。无统计学结果可证明年龄、性别、动脉瘤最大径、瘤颈宽度、支架辅助、Matrix占栓塞弹簧圈长度比例等因素影响Matrix栓塞动脉瘤的中长期预后。结论Matrix治疗颅内动脉瘤安全、有效,结合支架辅助技术可能会降低大型动脉瘤的复发率。Matrix弹簧圈有促进动脉瘤愈合的倾向,建议尽可能改善动脉瘤的血流动力学状况,此举将有利于动脉瘤长期愈后。Matrix弹簧圈的长期确切效果有待进一步随访观察及进行大样本的随机对照研究。     

Follow-up of intracranial aneurysms selectively treated with coils: Prospective evaluation of contrast-enhanced MR angiography

BACKGROUND AND PURPOSE: The aim of this study was to determine the feasibility and usefulness of contrast-enhanced MR angiography (CE-MRA) for the follow-up of intracranial aneurysms treated with detachable coils, by comparing CE-MRA with digital subtraction angiography (DSA) and 3D time-of- flight (TOF) MRA. METHODS: Thirty-two patients with 42 treated aneurysms were included in the study; 6 had been treated for multiple aneurysms. All MRAs were performed with a 1.5T unit within 48 hours of DSA. We performed 2 types of acquisition: a 3D TOF sequence and CE-MRA. Twenty-eight patients were included 1 year after endovascular treatment, and 4 patients, after 3 years or more. DSA was the technique of reference for the detection of a residual neck or residual aneurysm. RESULTS: Compared with DSA, the sensitivity of MRA was good. For the detection of residual neck, there was no significant difference between the results of 3D TOF MRA (sensitivity, 75%-87.5%; specificity, 92.9%, according to both readers) and CE-MRA (sensitivity, 75%-82.1%; specificity, 85.7%-92.9%). For the detection of residual aneurysm, sensitivity and specificity of both techniques were the same, respectively 80%-100% and 97.3%-100%. Therefore, CE-MRA was not better than 3D TOF MRA for the detection of residual neck or residual aneurysm. For large treated aneurysms, there was no difference between decisions regarding further therapy after CE and 3D TOF MRA, even though CE-MRA with a short echotime and enhancement gave fewer artifacts and better visualization of recanalization than 3D TOF MRA. The interpretation of transverse source images and the detection of coil mesh packing seemed easier with 3D TOF imaging. CONCLUSION: This prospective study did not show that CE-MRA was significantly better than 3D TOF MRA for depicting aneurysm or neck remnants after selective endovascular treatment using coils. For aneurysms treated with coils, 3D TOF MRA seems a valid and useful technique for the follow-up of coiled aneurysms.