Magnetic resonance angiography in suspected cerebral vasculitis

The purpose of this study was to determine the technical capacity and diagnostic accuracy of 3D time-of-flight magnetic resonance angiography (MRA) in suspected cerebral vasculitis in a retrospective analysis of MRA and digital subtraction angiography (DSA) in 14 young patients with clinical and/or radiological suspicion of cerebral vasculitis. A total of nine arteries were evaluated in each patient. Consensus review of DSA by three observers was the reference standard. The sensitivity for detecting a stenosis varied from 62 to 79% for MRA and from 76 to 94% for DSA, depending on the observer. The specificity for detecting a stenosis varied from 83 to 87% for MRA and from 83 to 97% for DSA. Using the criterion more than two stenoses in at least two separate vascular distributions to consider the examination as being true positive, the false-positive rates for MRA and DSA were comparable. MRA plays a role as the first angiographical examination in the diagnostic work-up of suspected cerebral vasculitis. When more than two stenoses in at least two separate vascular distributions are depicted on MRA, DSA is not expected to add a significant diagnostic contribution in a patient with suspected cerebral vasculitis. DSA remains necessary when MRA is normal or when less than three stenoses are seen.     

Bildgebung zerebraler Vaskulitiden

Cerebral vasculitis can have a variety of origins. Furthermore, there are no vasculitis-specific symptoms or imaging signs and vasculitis of the CNS can mimic many other neurological diseases, which require different treatment approaches. Thus, the clinical and radiological diagnosis of cerebral vasculitis is challenging. Magnetic resonance imaging (MRI) and MR angiography (MRA) should be the radiological imaging methods of choice to assess the degree of parenchymal damage and to detect vessel wall changes. If the results are unclear digital subtraction angiography (DSA) should be pursued in order to also detect changes in medium sized vessels. Vasculitis of small vessels cannot be detected by vascular imaging and requires brain or leptomeningeal biopsy. In this review we present the current diagnostic approach and a variety of imaging findings in cerebral vasculitis and discuss the main radiological differential diagnoses.     

Intracranial vascular stenosis and occlusion: evaluation with three-dimensional time-of-flight MR angiography.

To assess the usefulness of magnetic resonance (MR) angiography in the characterization of intracranial arterial stenosis and occlusion, a three-dimensional time-of-flight method was compared with conventional angiography in 214 vessels in 29 patients. Studies were independently interpreted by two neuroradiologists who scored each vessel as normal, narrowed, or occluded. Overall, 97% of normal vessels and 100% of occlusions were correctly graded. Sixty-one percent of stenoses were graded correctly; the remainder were graded as normal. The portions of the intracranial vessels near the skull base and especially the paracavernous and supraclinoid segments of the internal carotid arteries were areas of frequent over- and underestimation of stenosis due to the presence of dephasing artifacts. In patients with stenosis or occlusion, MR angiography also provided information regarding the presence of collateral flow in the circle of Willis. When used in conjunction with MR imaging of the brain and MR angiography of the extracranial carotid arteries, intracranial MR angiography allows a more complete evaluation of the patient with symptoms of cerebral ischemia or infarction.     

Comparison of magnetic resonance angiography and digital angiography of the epiaortic vessels

Atheromasic lesions and other pathologic conditions of the arterial vessels of the neck are the most frequent causes of cerebrovascular disease. Diagnostic imaging currently employs digital subtraction angiography (DSA), Doppler, and color-Doppler US to study these conditions. Digital subtraction intraarterial angiography (DSAA) can provide both an early diagnosis and an accurate preoperative depiction of neck vessels; however, in spite of its effective value, it still remains an invasive technique. Magnetic Resonance angiography (angio-MR) is the latest technique allowing the depiction of neck vessels morphology. It shares with digital angiography the capability of supplying spatial depiction of all the examined vascular structures, and with US its noninvasiveness. The authors investigated angio-MR capabilities in providing accurate and detailed images of neck arteries; the images were then compared with DSA ones. Thirty patients with cerebrovascular diseases were studied. MR imaging was performed with a 1.5 T unit with a dedicated coil, and gradient-echo sequences were employed. Refocused sequences for flow were acquired on both the coronal and the sagittal planes, with the following parameters: TR 40, TE 10, flip angle 25 degrees, acquisition volumes 80-35 mm, 64-15 frames. Digital angiography demonstrated 101 vascular lesions: 27 slight stenoses (less than 30%), 19 mild stenoses (31-70%), 12 severe stenoses (71-99%), 7 occlusions, 14 coilings, 7 kinkings, and 15 hypoplasias of vertebral artery. In slight stenoses, angio-MR underestimated the condition in 11/27 patients. In mild and severe stenoses, as well as in occlusive diseases, angio-MR tended to overestimate the condition. In coiling, kinking, and hypoplasia, angio-MR yielded the same results as DSA.     

Percutaneous Management of Occlusive Arterial Disease Associated with Vasculitis: A Single Center Experience

The purpose of this study was to evaluate the safety and effectiveness of percutaneous transluminal angioplasty for occlusive arterial disease associated with vasculitis. Eleven patients (10 women, 1 man; ages 35–82 years) with the diagnosis of vasculitis of the large vessels underwent interventional treatment during intraarterial angiography. The causes included giant cell arteritis (n = 8) and Takayasu arteritis (n = 3). Thirty-three occlusive lesions (including brachiocephalic and renal arteries, and arteries of upper and lower extremities) were treated with balloon angioplasty and/or stent placement. Follow-up included clinical examination, angiography, and color duplex ultrasound. Technical success was 100% (25/25) for stenoses and 50% (4/8) for occlusive lesions, representing all lesions combined from different anatomic locations. Dissection (n = 3) and arterial rupture with retroperitoneal hematoma (n = 1) was found in three patients. During follow-up (mean 12 months), restenoses (n = 8) and re-restenoses (n = 1) occurred in 8 vascular areas. Three of these lesions were treated with repeated PTA (n = 4). The cumulative primary clinical success rate was 67.6%, cumulative secondary success rate 74.4%, and cumulative tertiary success rate 75.9%. Interventional therapy in systemic vasculitis provides promising results in technical success rates and followup. Angioplasty may result in arterial injury, but the rate of complications is low.     

MRA对脑动脉炎的诊断价值(附9例报告)

目的 评价磁共振血管成像（MRA）对脑动脉炎的诊断价值。方法 回顾性分析9例经临床证实为脑动脉炎患的MRA表现，并与MRI表现对照。结果 9例患的所有病灶均局限于一侧大脑半球或小脑半球，形态多呈圆形，斑片状。病灶在T1WI像呈低、等信号，在W2WI像呈稍高、高信号。MRI表现主要为梗塞灶、出血灶、脑炎和脑膜炎的炎症性病灶。MRA更加清晰显示近端脑动脉不规则狭窄或截断，远端脑动脉缺如，两侧血管分布不对称。结论 MRA是一种切实可行的血管成像技术，它不仅可提高脑动脉炎的诊断准确性，而且有助于评估其预后。     

Dissection of epiaortic vessels: clinical appearance and potentiality of imaging techniques

PURPOSE: To analyse the major radiological and clinical features of dissections of the epiaortic vessels and evaluate the potential of imaging techniques on the basis of the findings reported in the literature over the last few years. MATERIALS AND METHODS: We evaluated 9 dissections (7 carotid lesions and 2 vertebral lesions) in 9 patients (5 women and 4 men; age range: 30-56 years) who came to our attention between September 1999 and June 2002. These were all stenoses and obstructions located in the cervical region and, in two patients, extended intracranially. The morphologic features were assessed in each case by colour-Doppler US, CT, MR or conventional angiography and correlated with clinical, therapeutic and distant progression patterns. Colour-Doppler US of the neck vessels was performed in 4 patients; CT angiography of neck and intracranial vessels was performed in 4 patients using a single-slice spiral scanner and a single contrast medium bolus injection, following unenhanced examination of the brain; MR angiography was performed in 6 patients after baseline examination using flow-dependent and/or angiographic sequences; conventional angiography was performed in 7 patients. Clinical manifestations at onset were peripheral neurological lesions in 5 cases and central ischaemic lesions in the remaining 4 cases. All patients underwent medical therapy (anticoagulants or antiaggregants). The follow-up was done by colour-Doppler US, MR and/or MR angiography; follow-up conventional angiography at 6-9 months was also performed in 6 patients. Distant progression was assessed on the basis of the degree of vascular re-canalization and the residual signs and symptoms. RESULTS: MR- and CT-angiography were diagnostic in all cases. In particular, diagnosis was obtained by MR-angiography in 4 patients and by CT-angiography in 3 patients. Conventional angiography yielded a diagnosis in 2 cases which had previously undergone non-contrast brain CT or MR without examination of neck vessels alone. Colour-Doppler US revealed non-specific wall and flow alterations in 2 cases, thus requiring further diagnostic studies. In patients with central neurological symptoms at onset the diagnosis was obtained within 48-72 hours, whereas in patients with initial peripheral neurological symptoms the time to diagnosis was significantly longer (up to 10 days) due to the poor specificity of the clinical picture and/or failed detection of the warning symptoms. Medical treatment gave rise to no major complications. Overall, distant progression was good: 6 patients recovered completely and 3 had mild to moderate residual neurological deficits. DISCUSSION AND CONCLUSIONS: Dissection of epiaortic vessels should always be considered as a probable cause of cerebral ischaemia in adults aged 20-50 years, particularly in the absence of vascular risk factors. Clinical assessment is fundamental for the diagnosis and treatment. Currently, CT and MR imaging techniques providing similar information are reliable diagnostic tools that can rapidly and non-invasively clarify suspicious clinical cases. Nevertheless, angiography continues to have an important role in the overall evaluation of disease severity in view of the possible endovascular or surgical treatment of complications.     

Cerebral MR angiography with multiple overlapping thin slab acquisition. Part II. Early clinical experience.

In a prospective, multicenter study of 164 patients, cerebral magnetic resonance (MR) angiography with multiple overlapping thin slab acquisition was evaluated for image quality and diagnostic accuracy. Of the 164 patients, 87 (53%) underwent either correlative cut-film angiography or surgery. The overall image quality was excellent in 90% of patient studies. Eighteen of 19 aneurysms were detected with MR angiography. The parent artery, the anatomy of the neck and dome, and the size were correctly shown in 17 of the 19 aneurysms. All 19 vascular malformations were seen with MR angiography. Venous malformations and single pedicle arteriovenous malformations were completely defined with MR angiography, while complete definition of complex arteriovenous malformations was frequently difficult. In cerebral tumors, the arteries and veins important in surgical planning were accurately shown in all cases. In ischemic cerebrovascular disease, MR angiography depicted all stenoses and occlusions of first- and second-order cerebral arteries. The inability to depict intraluminal filling defects in any but the large central arteries limited the ability of MR angiography to enable the specific diagnosis of embolic stroke.     

MR imaging features of Nipah encephalitis

OBJECTIVE: The newly discovered Nipah virus causes an acute febrile encephalitic illness in humans that is associated with a high mortality. The purpose of this study is to describe the MR imaging findings of Nipah encephalitis. MATERIALS AND METHODS: MR imaging of the brain was performed in 31 patients with Nipah encephalitis divided into three groups. The first group (14 patients) underwent MR imaging during the acute phase of the illness and the second group (10 patients) during the later phase of the acute illness. The third group consisted of six patients who underwent MR imaging because they experienced neurologic relapse and one patient who had late-onset encephalitis. Spin-echo T1- and T2-weighted sequences and T2-weighted fluid attenuated inversion recovery (FLAIR) sequences were performed. Contrast-enhanced MR imaging was performed in four patients. RESULTS: The FLAIR sequences revealed abnormalities in all patients studied. MR imaging findings in both the acute and later phases of encephalitis were similar; the main feature of both phases was the presence of discrete high-signal-intensity lesions, measuring 2-7 mm, disseminated throughout the brain, mainly in the subcortical and deep white matter of the cerebral hemispheres. Neither mass effect nor cerebral edema was seen. There was no correlation with the focal neurologic signs, depth of coma, and outcome of the patients. The lesions were attributed to widespread microinfarctions from underlying vasculitis of cerebral small vessels. Features found on MR imaging in relapsed and late-onset encephalitis differed from the features in acute encephalitis in that confluent cortical involvement was the prominent finding in the former, as opposed to discrete focal lesions in the subcortical and deep white matter in the latter. CONCLUSION: MR imaging is a sensitive and specific diagnostic tool for evaluating Nipah encephalitis.     

Antiphospholipid antibodies: findings at arteriography.

PURPOSEThe purpose of this study was to determine the frequency and types of abnormalities at arteriography in patients with antiphospholipid antibodies (APA) and ischemic cerebrovascular events.METHODSTwenty-three patients with APA and ischemic cerebrovascular events who underwent arteriography were identified. Patients over the age of 65 years were excluded. No patients met diagnostic criteria for systemic lupus erythematosus. All angiograms were reviewed by two neuroradiologists.RESULTSSeventeen patients (74%) between the ages of 28 and 64 years (average age, 40 years) had abnormal angiograms. Sixteen patients had arterial abnormalities and one had dural sinus thrombosis. Ten had solely intracranial abnormalities (nine arterial and one venous), six had solely extracranial arterial abnormalities, and one had both intracranial and extracranial arterial abnormalities. Intracranial arterial abnormalities included stem or branch occlusions of the cerebral or basilar arteries, which were generally solitary (six patients), and findings suggestive of vasculitis (four patients). Four patients had stenoses of the origins of two or more great vessels. Two patients had extracranial internal carotid artery stenoses or occlusions that were not typical of atheromatous disease, considered to be embolic in one patient. In another patient, a stenosis of the origin of the internal carotid artery was present that appeared typical of atheromatous disease. Infarctions were seen on CT or MR studies in 13 of 17 patients with abnormal angiograms.CONCLUSIONIn our group of patients, typical atheromatous lesions at the common carotid artery bifurcation were rare. Some lesions that are infrequent in the general stroke population (eg, vasculitis-like findings and stenoses at the origin of great vessels) were common. Patients with APA and cerebrovascular events appear to differ from the general stroke population with regard to types of arterial abnormalities seen at arteriography.     

A case of moyamoya-like vessels combined with brain anomaly

We report here a rare case of moyamoya-like vessels combined with brain anomaly. MR imaging revealed a small corpus callosum and stenosis of the internal carotid arteries. T2-weighted images revealed multiple hyperintense lesions in the cerebral deep white matter, suggesting ischemic or abnormal myelinated tissues. Cerebral angiography showed aplastic carotid siphons and anomalous aneurysmal dilatation of the petrous portion of the internal carotid arteries. The terminal portion of the internal carotid arteries and horizontal portion of the middle cerebral artery were stenotic with moyamoya-like vessels.     

Cerebral proliferative angiopathy depicted by four-dimensional computed tomographic angiography: A case report

Cerebral proliferative angiopathy is a rare cerebrovascular disorder characterized by diffuse abnormal vessels with intermingled brain parenchyma fed by many arteries and draining into many veins without high-flow arteriovenous shunts, which is usually confirmed by conventional digital subtraction angiography. However, dilution of the contrast medium due to the markedly increased blood flow and volume in cerebral proliferative angiopathy leads to low-contrast angiography. We report a 53-year-old man with cerebral proliferative angiopathy who underwent CT, MR imaging, MR angiography, digital subtraction angiography and 4D-CTA. The 4D-CTA exhibited abnormal vessels without early venous filling between the atrophic brain parenchyma in higher contrast than the angiography due to high spatial and time resolution, whereas the left external carotid angiography visualized the characteristic transdural supply more clearly than the 4D-CTA due to high vascular selectivity. Therefore, novel 4D-CTA and conventional angiography plays a complementary role in the accurate diagnosis of cerebral proliferative angiopathy. Taking invasiveness into account, 4D-CTA may be advantageous for the diagnosis of cerebral proliferative angiopathy based on the characteristic imaging findings.     

Cerebral blood flow: assessment with dynamic contrast-enhanced T2*-weighted MR imaging at 1.5 T

The authors assessed regional cerebral blood flow dynamics with magnetic resonance (MR) imaging enhanced with gadolinium diethylenetriaminepentaacetic acid (DTPA). After bolus administration of Gd-DTPA, rapid T2*-weighted gradient-echo images were acquired. Image acquisition time ranged from 2 to 3 seconds. The signal intensity (SI) of brain tissue and blood vessels markedly decreased during the first pass of contrast agent through the brain due to the local field inhomogeneity caused by the concentrated paramagnetic contrast agent. The method was used in 18 subjects with no cerebrovascular disease and 32 patients with stroke, vascular stenosis, arteriovenous malformation, and cerebral neoplasm. Comparison with intracranial angiography was performed in three patients and with single-photon emission computed tomography of blood flow in four. The change in T2* relaxation rate was approximately linearly related to the dose of contrast agent. The SI change increased as the echo time was lengthened. Regions in cerebral infarcts, metastases, and arteriovenous malformations showed different enhancement patterns than those of edema around a lesion and of normal brain tissue. Abnormal circulation times in patients with vascular stenoses were demonstrated. The method provides information about cerebral blood flow dynamics not available from conventional MR imaging and MR angiography.     

长巨脑动脉的影像诊断

目的探讨长巨脑动脉的影像特征.材料与方法对13例患者的MRI表现、DSA或MRA显示的异常血管分布和形态进行分析.结果MRI能够显示位于桥前池、鞍上池等处粗大的血管流空信号、病变压迫的确切部位(颅神经、脑干、颞叶内侧)、脑缺血灶以及伴随的脑动静脉畸形.无以往的出血表现.血管造影显示延长、增宽和扭曲的脑血管,8例发生在椎-基底动脉,2例发生在颈动脉,3例两系统同时受累.有1例伴有一侧颈动脉闭塞,另2例分别伴发脑动静脉畸形和多发脑动脉瘤.结论MRI和血管造影技术相结合,有助于对该病进行全面评价.     

Magnetresonanz-Angiographie bei entzündlichen Hirnerkrankungen

In this review, we discuss the diagnostic potential of time of flight (TOF) MRA and contrast enhanced (CE) MRA in inflammatory disorders of the meninges and the brain. Cerebrovascular complications are frequently observed during infectious meningoencepalitis. 3D TOF-MRA and CE-MRA are complementary for the detection of basal intracranial artery stenosis and septic cerebral vein and sinus thrombosis due to secondary vasculitis. MRA reveals stenosis and occlusion as indirect signs of vasculitis, whereas MRI shows the inflammation of the brain and meninges and occasionally the vessel wall, together with the ischemic or hemorrhagic complication. In case of septic emboli MRA can detect peripheral occlusions and "mycotic" aneurysms. For the diagnosis of noninfectious vasculitides of the intracranial vessels, high resolution 3D TOF-MRA is superior to CE-MRA for the detection of multiloculated segmental stenoses. However, there are presently no prospective studies on the sensitivity and specificity of MRA for these indications. Therefore, only positive MRA results can directly influence clinical management. In case of normal MRA, confirmation by catheder angiography may still be required.     

The advantages of MRI and MRA for diagnosing Beh?et's disease and internal jugular vein thrombosis.

Beh?et's disease is a multisystem disorder characterized by recurrent aphtous ulcers of mucosal membranes, skin lesions, and vasculitis. The prevalence of vascular involvement is about 25% and this is the leading cause of death in Beh?et's disease. Jugular vein involvement is an unusual manifestation of Beh?et's disease. Medical insertion of needles into veins or arteries can induce thrombosis or aneurysms. Thus, diagnostic studies or therapy can aggravate the disease and even be fatal. We report a patient with Beh?et's disease and rare internal jugular vein thrombosis. We also demonstrate the ability of noninvasive magnetic resonance imaging and magnetic resonance angiography to aid in the diagnosis and evaluation of vascular involvement in Beh?et's disease, without risking iatrogenic complications.     

Contrast-enhanced 3D MR angiography of the carotid artery: comparison with conventional digital subtraction angiography

BACKGROUND AND PURPOSE: Since 1996, several preliminary studies have shown the usefulness of contrast material-enhanced MR angiography for imaging supraaortic vessels. The aim of this study was to compare the accuracy of contrast-enhanced 3D MR angiography with that of digital subtraction angiography (DSA) in the evaluation of carotid artery stenosis. METHODS: A blinded comparison of first-pass contrast-enhanced MR angiography with conventional DSA was performed in 120 patients (240 arteries). MR angiography was performed with a 1.5-T magnet with gradient overdrive equipment, by using a coronal radiofrequency-spoiled 3D fast low-angle-shot sequence after the intravenous injection of gadodiamide. The guidelines of the North American Symptomatic Carotid Endarterectomy Trial for measuring stenosis of the internal carotid artery were applied on maximum intensity projection (MIP) images and conventional catheter angiograms. RESULTS: Grading of stenoses on MR angiograms agreed with grading of stenoses on DSA images in 89% of arteries. In the severe stenosis group (70-99%), agreement was 93%. All internal carotid occlusions (n = 28) and seven of nine pseudo-occlusions were accurately detected with contrast-enhanced MR angiography. The correlation between MR angiography and DSA for determination of minimal, moderate, and severe stenoses and occlusion was statistically significant (r = 0.91, P<.001). CONCLUSIONS: This investigation with a large number of patients confirms that contrast-enhanced MR angiography could become a diagnostic alternative to DSA in the treatment of patients with carotid artery disease.     

Contrast-enhanced three-dimensional fast imaging with steady-state precession (FISP) MR angiography of supraaortic vessels: preliminary results.

BACKGROUND AND PURPOSEThe purpose of this study was to assess the effectiveness of contrast-enhanced fast three-dimensional (3D) MR angiography in depicting both the carotid and vertebral arteries in their cervical portions and to compare MR angiography with conventional angiography for the evaluation of arteriosclerotic disease.METHODSTwenty-seven patients with ischemic cerebral events in the anterior (n = 18) and posterior (n = 9) circulation underwent contrast-enhanced 3D MR angiography in the coronal plane. MR angiograms were examined in a blinded fashion by two observers independently. Stenosis was classified according to the appearance of the residual lumen (no stenosis, mild stenosis, moderate stenosis, severe stenosis, occlusion). Conventional angiography was used as the standard of reference.RESULTSProximal great vessels and carotid siphons were not assessable on MR angiograms in 35% of cases owing to limited coverage. All cervical and petrous segments of the internal carotid arteries (ICAs) and 93% of the extracranial vertebral arteries were assessable. Flow-related artifacts were observed in seven cases of severe stenosis, including three with signal void at the site of narrowing and four with signal loss in the distal ICA. Interobserver agreement was good and significant. Overall agreement between 3D MR angiography and conventional angiography was good for the anterior and posterior circulations despite a tendency toward overestimation of stenoses on MR angiograms. Clinically relevant stenoses and occlusions were correctly identified on 3D MR angiograms, providing good sensitivity and specificity.CONCLUSIONContrast-enhanced 3D MR angiography is a promising tool for assessing arteriosclerotic lesions of supraaortic vessels. Further studies with larger groups are required to determine its value for patient care.     

Silent microemboli related to diagnostic cerebral angiography: a matter of operator’s experience and patient’s disease

Introduction The aim of the present investigation was to elucidate in a large consecutive patient cohort whether the level of training has an effect on the number of microemboli detected by diffusion-weighted imaging (DWI) and which additional risk factors can be identified.Methods A total of 107 consecutive patients in whom a diagnostic cerebral angiography had been performed were prospectively investigated with DWI; 51 angiographies were performed by experienced neuroradiologists, 56 by neuroradiologists in training. Results In 12 patients (11.1%), a total of 17 new lesions without any clinically overt neurological symptoms were identified. Of these, 12 patients, 11 (91.7%) with 16 lesions were investigated by junior neuroradiologists. In 11 of 12 patients with DWI abnormalities (91.7%), risk factors could be identified (atherosclerotic vessel wall disease, vasculitis, hypercoagulable states). Experienced neuroradiologists performed 21 of 48 angiographies (43.8%) on patients with the above-mentioned risk factors, whereas junior neuroradiologists performed 27 angiographies in this subgroup (46.2%). The rate of diffusion abnormalities in patients with risk factors was 11/48 (22.9%)—considerably higher than in patients without risk factors (1/59; 1.7%).Conclusion The level of experience and the nature of the underlying disease are predictors of the occurrence of cerebral ischemic events following neuroangiography. Alternative diagnostic modalities should be employed in patients who are investigated for diseases with the highest risk of angiographic complications (i.e., vasculitis, and arteriosclerotic vessel wall disease). If diagnostic angiography remains necessary in these patients, the highest level of practitioner training is necessary to ensure good patient outcome.     

三维增强MR脑血管成像技术探讨

目的:探讨三维增强MR脑血管成像技术及其临床应用价值.方法:行脑血管3D-CE-MRA检查46例,对其显示脑血管能力、病变的敏感性与真实性进行分析,并与3D-TOF-MRA比较.结果:3D-CE-MRA显示全脑动脉及细小分支和静脉系统.本组动脉瘤15例(17个),3D-TOF-MRA显示13个,3D-CE-MRA全部显示.脑动脉狭窄17例,3D-TOF-MRA表现动脉中断和闭塞,3D-CE-MRA表现出动脉狭窄.动静脉畸形6例,3D-CE-MRA显示出供血动脉、畸形血管和引流静脉.脑肿瘤8例,3D-CE-MRA能显示肿瘤组织动态增强状态.结论:3D-CE-MRA诊断脑血管病变敏感率、准确率高,具有临床应用价值.