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   

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.     

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。     

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.     

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.     

Comparison of 3D TOF-MRA and 3D CE-MRA at 3 T for imaging of intracranial aneurysms

Purpose

To compare 3 T elliptical-centric CE MRA with 3 T TOF MRA for the detection and characterization of unruptured intracranial aneurysms (UIAs), by using digital subtracted angiography (DSA) as reference.

Materials and methods

Twenty-nine patients (12 male, 17 female; mean age: 62 years) with 41 aneurysms (34 saccular, 7 fusiform; mean diameter: 8.85 mm [range 2.0–26.4 mm]) were evaluated with MRA at 3 T each underwent 3D TOF-MRA examination without contrast and then a 3D contrast-enhanced (CE-MRA) examination with 0.1 mmol/kg bodyweight gadobenate dimeglumine and k-space elliptic mapping (Contrast ENhanced Timing Robust Angiography [CENTRA]). Both TOF and CE-MRA images were used to evaluate morphologic features that impact the risk of rupture and the selection of a treatment. Almost half (20/41) of UIAs were located in the internal carotid artery, 7 in the anterior communicating artery, 9 in the middle cerebral artery and 4 in the vertebro-basilar arterial system.All patients also underwent DSA before or after the MR examination.

Results

The CE-MRA results were in all cases consistent with the DSA dataset. No differences were noted between 3D TOF-MRA and CE-MRA concerning the detection and location of the 41 aneurysms or visualization of the parental artery. Differences were apparent concerning the visualization of morphologic features, especially for large aneurysms (>13 mm). An irregular sac shape was demonstrated for 21 aneurysms on CE-MRA but only 13/21 aneurysms on 3D TOF-MRA. Likewise, CE-MRA permitted visualization of an aneurismal neck and calculation of the sac/neck ratio for all 34 aneurysms with a neck demonstrated at DSA. Conversely, a neck was visible for only 24/34 aneurysms at 3D TOF-MRA. 3D CE-MRA detected 15 aneurysms with branches originating from the sac and/or neck, whereas branches were recognized in only 12/15 aneurysms at 3D TOF-MRA.

Conclusion

For evaluation of intracranial aneurysms at 3 T, 3D CE-MRA is superior to 3D TOF-MRA for assessment of sac shape, detection of aneurysmal neck, and visualization of branches originating from the sac or neck itself, if the size of the aneurysm is greater than 13 mm. 3 T 3D CE-MRA is as accurate and effective as DSA for the evaluation of UIAs.     

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.     

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.     

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.     

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.     

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.     

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.     

颅内动脉瘤的比较影像学研究

目的：比较分析DSA、3D TOF MRA及CT对颅内动脉瘤的诊断价值。方法：30例颅内动脉瘤均经血管造影和手术征实，所有病例均先后作CT、3D TOF MRA及DSA检查，对其影像学特征进行比较研究。结果：DSA显示全部瘤体，呈囊状、梭形局部突出影；3D TOF MRA显示28个动脉瘤(2个假阳性)，4个未显示，其显示动脉瘤的敏感性为86．7％，假阳性为6．7％。CT显示瘤体及蛛网膜下腔出血提示动脉瘤者15例，占50％；无异常者8例，占26．7％。结论：DSA仍然是诊断颅内动脉瘤的金标准‘3D TOF MRA虽然是显示颅内动脉瘤的敏感方法之一，但对确定治疗方案价值低于DSA；CT敏感性较差，但可通过显示其间接征象提示动脉瘤。     

Surveillance of intracranial aneurysms treated with detachable coils: a comparison of MRA techniques

Two MRA techniques were evaluated for the follow-up of coiled intracranial aneurysms. Twenty-nine coiled aneurysms were evaluated for a total of 36 follow-up assessments using 3D time-of flight MRA (TOF MRA), an auto-triggered elliptic–centric-ordered three-dimensional gadolinium-enhanced MR angiogram (ATECO MRA), as well as a selective digital subtraction angiography (DSA), which served as the gold standard. Confident visualization was seen in 36 (100%) of ATECO MRAs and in 32 (89%) of the TOF MRAs. Eleven residual aneurysm components (RACs) greater than 2 mm were described on DSA. Of these, nine were seen on ATECO MRA (sensitivity of 81% and specificity of 88%) and four were seen on TOF MRA (sensitivity of 40% and specificity of 90%). The two RACs not seen on ATECO MRA both measured 3 mm. The six RACs not seen on TOF MRA measured 3, 4 and 5 mm. ATECO MRA provides a non-invasive reliable angiogram for the surveillance of coiled aneurysms and is superior to TOF MRA for this purpose.     

Accuracy of 3 T MR angioraphy in vertebral artery stenosis and coincidence with other cerebrovascular stenoses

Introduction

Ostium of vertebral artery (VA) is a common site of pseudostenosis on contrast-enhanced MR angiography (CE-MRA). The purpose of this study was to determine the diagnostic accuracy of CE-MRA at 3 T in the evaluation of ostial stenosis of VA and to find associated coincidental stenoses using logistic regression analysis.

Methods

One hundred and thirty-five VA ostial regions from 72 patients who received CE-MRA of neck vessels, intracranial time of flight (TOF) MRA, and digital subtraction angiography (DSA) were retrospectively reviewed. The sensitivity and specificity of the CE-MRA in detection of ostial stenosis were calculated with reference standard of DSA. Ostial stenosis on MRA was correlated with coincidental lesions in intracranial and cervical arteries by logistic regression analysis.

Results

The sensitivity and specificity of the CE-MRA were 100% and 80.4% for detection of significant stenosis. In case of significant stenoses, CE-MRA showed a tendency of overestimation with a false-positive rate of 52.5%. Logistic regression analysis showed that the stenoses of middle cerebral artery (MCA) on TOF MRA was associated with significant stenoses of VA ostia (OR?=?5.84, 95% confidence intervals 1.41–24.17).

Conclusion

CE-MRA is sensitive in detection of VA ostial stenosis although it has high false-positive rate. True positive ostial stenosis should be considered in cases of coincidental stenoses of MCA on TOF MRA.     

螺旋CT血管造影在脑动脉瘤诊断及治疗中的应用—兼与MR血管造影比较

目的探讨无创性的螺旋CT血管造影(SCTA)与MR血管造影(MRA)对脑动脉瘤的诊断价值以及对治疗的指导价值,并对两者作比较.材料和方法28例患者同时行SCTA、MRA、DSA,以DSA作为金标准,对SCTA与MRA作比较.结果(1)23例行SCTA及时间飞跃法(TOF)MRA者,SCTA诊断脑动脉瘤的准确性高于TOFMRA,但差异无显著统计学意义(p＞0.05).(2)SCTA较TOFMRA测量脑动脉瘤的最大径准确性高(p＜0.01),TOFMRA测量值常偏小.(3)SCTA测量的栓塞治疗最佳投照角度与DSA符合率94.7%.(4)动态增强(DCE)MRA的图像清晰度及价值与SCTA相似.结论SCTA对体积小、破裂出血的脑动脉瘤的检出率以及对动脉瘤测量的精确性高于TOFMRA,SCTA可较准确地测量动脉瘤栓塞治疗的最佳投照角度,MRA是脑动脉瘤电解可脱弹簧圈(GDC)栓塞术后随访的较好方法,DCEMRA的实用价值与SCTA相似.     

CTA与MRA诊断动脉瘤及评估动脉瘤破裂风险的比较

 目的 比较CT血管造影术(CT angiography,CTA)与磁共振血管造影(magnetic resonance angiography,MRA)诊断动脉瘤与动脉瘤破裂的风险评估价值。方法 48例高度怀疑为颅内动脉瘤患者随机分为两组,每组24例,记为Ⅰ组和Ⅱ组,其中Ⅰ组行CTA+DSA检查,Ⅱ组行MRA+DSA检查。比较CTA及MRA对颅内动脉瘤的诊断灵敏度、诊断特异性、阳性预测值、阴性预测值及准确率。比较CTA及MRA对5 mm以上动脉瘤的诊断价值。结果 MRA诊断颅内动脉瘤的诊断灵敏度、诊断特异性、阳性预测值、阴性预测值、准确率较CTA稍低,但二者差异无统计学意义。CTA与三维增强MR血管成像(3D CE-MRA)对5 mm以上动脉瘤的诊断能力相当,但与三维时间飞跃法MR血管成像(3D TOF MRA)相比,CTA与CE-MRA的诊断灵敏度、诊断特异性、阳性预测值、阴性预测值、准确率明显较高,差异有统计学意义(P<0.05);CTA能更清楚地显示瘤颈。结论 CTA和MRA可作为诊断动脉瘤与动脉瘤破裂的风险评估的首要手段,CTA诊断的准确率及三维形态高于MRA。     

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.     

三维时间飞跃法MR血管成像检出颅内动脉瘤的研究

目的分析三维时间飞跃法MR血管成像(3D TOF MRA)检出颅内动脉瘤的价值。资料与方法 36例进行了3D TOF MRA且有数字减影血管造影(DSA)和/或手术结果为对照的患者纳入本研究。以DSA和/或手术结果为参照标准,以患者为分析单位评价3D TOF MRA检出颅内动脉瘤的能力。对3D TOF MRA均检出动脉瘤者,分别测量动脉瘤的长径、短径和瘤颈,进行相关性分析。结果 36例患者中DSA和/或手术检出28例患者有28个动脉瘤,8例患者无动脉瘤;3D TOF MRA检出31例患者31个动脉瘤,5例患者无动脉瘤。以DSA和/或手术结果为参照,以患者为分析单位,3D TOF MRA检出颅内动脉瘤的敏感性、特异性和准确性分别为89.3%、75.0%、75.0%。3D TOF MRA和DSA在显示颅内动脉瘤长径、短径和瘤颈的差别无统计学意义,并且有很好的正相关性。结论 3D TOF MRA在诊断颅内动脉瘤方面具有高的敏感性和中等的特异性,高的假阳性率提示在作出小动脉瘤的诊断时需谨慎。     

三维动态增强MR血管造影对颅内动脉瘤的诊断价值

目的 评价三维动态增强磁共振血管造影(3D DCE-MRA)在颅内动脉瘤诊断中的价值。方法 对54例高度怀疑有颅内动脉瘤的病人行3D DCE-MRA检查，随后行DSA造影及可行的血管内栓塞治疗。3D DCE-MRA用超快速三维梯度回波序列(3D FISP)(钆喷替酸葡甲胺0．2mmol／kg,1次扫描时间10s)，工作站上三维重建，比较3D DCE-MRA及常规DSA在显示动脉瘤、瘤颈及与载瘤动脉关系上的优劣，及对血管内栓塞治疗的价值。结果 39例脑动脉瘤患者共45个动脉瘤，3D DCE-MRA对动脉瘤的敏感度为96％，特异度73％，准确度90％。3D DCE-MRA对动脉瘤细节及瘤颈的显示明显优于常规DSA，尤其是颈内动脉海绵窦部及椎动脉近小脑后下动脉的动脉瘤，可指导DSA显示动脉瘤方向及预先制定治疗方案。但对周边部及动脉分岔处小动脉瘤的诊断应谨慎。结论3D DCE-MRA能无创有效地诊断颅内动脉瘤，所提供的三维信息对治疗方案的制定具有极大帮助。当诊断有怀疑时，应结合DSA检查。