烟雾病的MRI、MRA诊断价值

 目的探讨MRI、MRA对烟雾病(Moyamoya病)的诊断价值.方法对11例Moyamoya病患者行MRI和MRA检查,MRI包括横轴位和矢状位T1WI、T2WI、FLAIR;MRA采用3D TOF法,3例行增强MRA.结果MRI表现为:(1)Moyamoya血管:双侧3例,单侧8例;(2)脑梗死和脑软化灶11例;(3)局部脑萎缩3例.MRA表现为3例双侧颈内动脉狭窄,双侧大脑中、前动脉闭塞,大脑后动脉形成异常血管网;6例右侧颈内动脉、大脑中动脉狭窄;2例左侧颈内动脉、大脑中动脉狭窄.结论MRI能良好的显示脑内病变,MRA能较完整的显示异常血管,MRI与MRA相结合可作为烟雾病诊断的首选检查方法.     

Moyamoya病的MRI和MRA表现:儿童与成人患者的比较

目的　总结Moyamoya病患者的MRI和MRA表现。方法　分析 10例Moyamoya病患者 ( 6例儿童 ,4例成人 )的MRI和MRA表现。MRA影像主要研究颈内动脉和大脑中动脉的狭窄以及侧支血管的出现情况 ,并由此进行分期 ;MRI影像主要研究脑梗塞的发生部位。并分别对儿童和成人的MRA和MRI表现进行比较。结果　儿童和成人患者的MRA表现均为颈内动脉、大脑中动脉狭窄 ,伴侧支血管形成。而MRI表现两组有较明显的差别 ,儿童患者以大脑半球皮质和 /或皮质下梗塞为主 ,达 75 % ( 9/12 ) ,成人患者以大脑半球半卵圆中心脑白质和基底节区腔隙性梗塞为主 ,达 87.5 % ( 7/8)。结论　MRI和MRA是评价Moyamoya病的一种很好的影像学方法。儿童与成人Moyamoya病的MRI表现不同可以解释其临床表现上的差异。     

MRA评估TIA患者脑血流量变化

目的 联合应用电影相位对比磁共振血管成像(cine PC MRA)、三维时间飞跃磁共振血管成像(3D TOF MRA)和三维对比增强磁共振血管成像 (3D CE -MRA)评估一过性脑缺血发作(TIA)患者全脑血流量和供血动脉病变对血流量的影响.资料与方法 采用MRA对41例TIA患者、30例正常人和30例脑梗死者的全脑血流量和脑供血动脉进行对照研究.结果 30例无脑动脉严重狭窄的TIA患者与30例正常人之间的全脑血流量差异无统计学意义(P=0.101).有颈内动脉(ICA)/椎-基底动脉(V-BA)严重狭窄的11例TIA患者与18例脑梗死患者的全脑血流量差异无统计学意义(P=0.150),但脑梗死患者合并大脑前动脉(ACA)、大脑中动脉(MCA)和大脑后动脉(PCA)狭窄或闭塞的概率较大(P=0.018).结论 无脑动脉严重狭窄的TIA患者与正常人之间的全脑血流量无明显差异,而有脑动脉严重狭窄的TIA脑梗死患者的全脑血流量无明显差异.     

Assessment of borderzone ischemia with a combined MR imaging-MR angiography-MR spectroscopy protocol

We attempted to assess whether magnetic resonance imaging (MRI)-MR angiography (MRA)-MR spectroscopy (MRS) measurements can be used in the differentiation of patients in whom severe carotid lesions result in chronically hypoperfused regions and in whom the collateral capacity is sufficient to maintain a normal cerebral blood flow. Sixty-six patients with severe stenosis of the internal carotid artery (ICA) and 19 control subjects underwent MRI, 1H MRS, and MRA. Anaerobic metabolic changes in the middle cerebral artery (MCA) territory were studied by assessing N-acetyl-L-aspartate (NAA)/choline and lactate/ NAA ratios. Quantitative flow was measured in the ICA, in the basilar artery, and in the MCA. Thirty-four patients had borderzone infarcts, 16 patients had territory infarcts, and 16 patients had no infarcts on MRI. Patients with border-zone infarcts had significantly reduced flow in the ICA (P < 0.001) and in the MCA (P < 0.05) and decreased NAA/ choline ratios (P < 0.001) in non-infarcted regions compared with control subjects (P < 0.001) but also compared with patients with territory infarcts (P < 0.05) and patients without infarcts (P < 0.05). Flow measurements in the ICA and MCA and metabolic measurements in the MCA territory can be applied to select patients in whom cerebral perfusion pressure is insufficient to maintain normal cellular integrity.     

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。     

脑血管畸形磁共振血管成像与脑血管造影对照研究

目的：探讨了ＴＯＦ法ＭＲＡ评价脑血管畸形的价值及限度，材料与方法：２９例经ＭＲＩ（ｎ＝２９），脑血管造影（ｎ＝１５）和／或手术病理（ｎ＝１０）证实的脑血管畸形（ＡＶＭ２４例，ＡＶＦ２例，隐匿性ＡＶＭ３例）患者进行ＴＯＦ法ＭＲＡ检查，应用１．０Ｔ超导ＭＲ系统的二维或三维ＦＩＳＰ序列（预置０～３条预饱和带）和ＭＩＰ图像后处理技术，１５例同时经股动脉行全脑血管造影，采用Ｋａｐｐａ统计量对两种血管成像方法     

MRI和MRA对烟雾病的诊断价值

目的：评价ＭＲＩ和ＭＲ血管成像（ＭＲＡ）在烟雾病中的诊断价值。材料与方法：回顾性分析２３例烟雾病患者的ＭＲＩ和ＭＲＡ资料，ＭＲＡ采用三维时间飞跃法。结果：２３例患者ＭＲＡ图像均有不同程度的颈内动脉分叉处的血管狭窄／闭塞，１８例基底节区异常网状的血管和１４例软脑膜侧支循环血管显示清晰。ＭＲＩ上显示了所有患者的脑实质改变和１５例颈内动脉分叉处的血管狭窄／闭塞改变，所有患者根据其ＭＲ上脑血管的改变均可做出正确的诊断。结论：ＭＲＡ结合ＭＲＩ能对烟雾病患者做出正确的诊断和较准确的分期，同时可用于烟雾病患者的随访检查和术后复查。     

Magnetic resonance angiography in potential live renal donors: a joint radiological and surgical evaluation

AIM: To assess the impact of a joint surgical and radiological audit on the accuracy of contrast-enhanced magnetic resonance angiography (MRA) reports in the evaluation of potential renal donors. MATERIALS AND METHODS: We analysed the records of live renal donors who underwent gadolinium-enhanced MRA as part of the pre-operative evaluation to assess renal vasculature between August 1999 and July 2002 when feedback from surgical findings to radiology had been available. In cases of discrepancy between MRA reports and surgical findings, studies were retrieved from the magnetic resonance imaging (MRI) workstation and subjected to detailed joint clinical and radiological review. Scan quality was assessed and sources of discrepancy were identified. RESULTS: There were 45 donors, 23 men and 22 women with a mean age of 41 years. Reported MRA findings were fully confirmed at surgery in 38 of 45 cases. These images were not analysed further. In seven donors the findings at surgery were discrepant with the radiological reports: there were four cases of "missed" early branches and three cases of "missed" accessory arteries. In the first year of the audit there were four discrepant cases out of 18 (22%), all of which were radiological reporting errors. The number of discrepant cases in the second year was two out of 19 cases (11%). Neither of these was a radiological reporting error. There was one "missed" early renal artery branch in the third year of audit, which was identified on MRA review. CONCLUSION: The study highlights the importance of detecting and clearly reporting not only accessory renal arteries, but also early renal arterial branches in the pre-operative evaluation of renal donors. The accuracy of pre-operative MRA in potential renal donors is high, but radiological reporting of MRA examinations is improved through careful clinical feedback, audit and interdisciplinary co-operation.     

磁共振灌注加权成像在脑梗死诊断中的初步应用研究

目的：探讨脑梗死的磁共振灌注加权成像（ＰＷＩ）表现并评价ＰＷＩ在不同时期脑梗死诊断中的应用价值。材料和方法：应用梯度回波ＥＰＩ（平面回波）序列对１９例脑梗死患者进行了２６例次注射造影剂后的ＰＷＩ。通过工作站重建相对局部脑血容量（ｒＣＢＶ）图。计算脑梗死中心区和边缘区与对侧相应部位的ｒＣＢＶ比值和ＭＴＴ比值,并分析ＰＷＩ表现与ＭＲＡ（１９例次）表现之间的关系。结果：除恢复期以外,脑梗死病社中心多数表现为ｒＣＢＶ减少和ＭＴＴ增加;ＭＲＡ显示有血管闭塞或严重狭窄的脑梗死较ＭＲＡ未见血管异常的脑梗死之病灶中心ｒＣＢＶ减少和ＭＴＴ增加更为显著。结论：ＰＷＩ可以反映脑梗死区的血流动力学改变信息,与常规ＭＲＩ相结合,可同时反映脑梗死的形态和功能变化。     

MR imaging and angiography in tuberculous meningitis

MRI was performed on 26 patients with tuberculous meningitis, with particular reference to document the cranial nerve abnormalitics. MR angiography (MRA) was performed in 20 of the patients. Meningeal enhancement in the basal cisterns or over the convexity of brain was seen in all patients; two show ependymal enhancement. Tuberculomas, single (3), multiple (12) or miliary (2) were detected in 17 patients. Of the 9 patients with cranial nerve palsies, 7 showed contrast enhancement with or without thickening of the involved nerve. Abnormality signal intensity of the involved nerve was seen on proton density and T₂-weighted images in one of these patients. MRA revealed focal arterial narrowing in 10 patients, the vessels commonly affected being the terminal segment of the internal carotid artery and the proximal segments of the middle and anterior cerebral arteries. One patient also had a small aneurysm of the proximal middle cerebral artery. Infarcts, haemorrhagic (8) or bland (6), were detected in 14 patients; most were the basal ganglia and internal capsules, large middle or anterior cerebral arterial territory infarcts being seen in only two cases.     

缺血性脑血管病颈动脉狭窄15例影像诊断

目的　评价颈动脉狭窄无创性影像学检查方法的临床应用价值 ,探讨颈动脉狭窄与缺血性脑血管病之间的联系。材料与方法　对 15例 3 0支颈动脉行多普勒超声 (DUS)、磁共振血管造影 (MRA)及头部CT、MRI检查。其中 5例同时行颈动脉CT血管造影 (CTA) ,4例与DSA对照 ,6例颈动脉重度狭窄者行颈动脉内膜切除术。结果　 15例 3 0支颈动脉 ,轻度狭窄 ( <3 0 % ) 8支 ,中度狭窄 ( 3 0 %～ 69% ) 6支 ,重度狭窄 ( 70 %～ 99% ) 8支 (均为一侧 ) ,闭塞 2支 ,未见狭窄 6支。 8支颈动脉重度狭窄者狭窄侧腔隙性脑梗死 5例 ,狭窄对侧皮层梗死 1例 ,双侧脑梗死 1例 ,未见异常 1例。颈动脉闭塞侧大脑中动脉分布区脑梗死 2例。CTA显示硬化斑块 3例。结论　颈动脉狭窄与脑梗死的发生、发展密切相关。DUS、MRA、CTA结合使用能够在颈动脉狭窄的筛选、诊断、监测中发挥重要作用。     

烟雾病MRI和MRA诊断价值(附16例报告)

目的；评价MRI和MRA对烟雾病的诊断价值。方法：分析16例烟雾病患者的MRI、MRA表现和临床资料。MRA采用三维时间飞跃法。结果：16例患者MRA检查均显示不同程度的颈内动脉分叉以上狭窄或闭塞，其中17支后交通动脉增粗，4支眼动脉增粗；16例显示基底节区异常血管网，其中6例同时显示后部异常血管网；10例显示软脑膜吻合支增多；MRI显示脑出血或脑梗塞等脑实质改变，并能显示基底节区异常血管点状流空。结论：MRI和MRA是诊断烟雾病的有效非创伤性检查方法。对该病的诊断、筛选、随访和外科5一的评价有较大价值。     

脑性瘫痪的MRI特征

目的:探讨脑性瘫痪(脑瘫)患儿的头颅MRI表现及其与脑瘫类型的关系。方法:回顾性分析81例脑瘫患儿的临床资料与MRI表现。结果:81例脑瘫患儿MRI异常率为85.2%,痉挛型双瘫、四肢瘫、偏瘫、不随意运动型脑瘫、共济失调型脑瘫、肌张力低下型脑瘫和混合型脑瘫MRI异常率分别为92.9%、100%、100%、60%、87.5%、50%和81.8%。各类型脑瘫的MRI异常表现不同,痉挛型双瘫以脑室周围白质软化(PRL)为主,偏瘫型突出表现为单侧脑损伤,四肢瘫表现为广泛、弥漫、双侧脑损伤,不随意运动型表现为基底节病变或PVL,共济失调型绝大部分存在先天性小脑发育不全。结论:MRI有助于评价各型脑瘫的病理特点,对脑瘫病因的推测有帮助。     

Changes in visibility of intracranial arteries on MRA with normal ageing

We investigated age-related changes in the visibility of intracranial arteries on magnetic resonance angiography (MRA) and the influence of risk factors for stroke. We studied 230 adult patients without specific neurological deficits. MRA was performed using the three-dimensional time-of-flight technique with a spoiled gradient-recalled acquisition sequence. We classified internal carotid artery (IC) and the horizontal (M1) and distal (beyond M2) middle cerebral segments into 4 grades. Linear regression revealed a significant negative relation between age and the quality of demonstration on MRA. For IC and M1, the score was significantly lower in subjects with risk factors than in those without. The distal MCA was poorly seen in patients without a history of hypertension or lacunar infarcts. A marked correlation was observed between visibility and age patients with no history of hypertension, diabetes mellitus and hyperlipidaemia. We suggest that atherosclerotic change and decline in flow velocity with normal ageing are factors leading to decreased visibility on MRA. Received: 13 January 1998 Accepted: 6 January 1999     

Comparison of digital subtraction angiography with gadolinium-enhanced magnetic resonance angiography in the diagnosis of renal artery stenosis

Renal artery stenosis (RAS) is a treatable cause of hypertension and renal failure for which no ideal screening technique is currently available. We evaluated the use of dynamic gadolinium-enhanced magnetic resonance angiography (MRA) for the diagnosis of RAS. Sixty-two patients with secondary hypertension were enrolled in the study. All patients had conventional renal angiography and gadolinium enhanced MRA. The sequence used was a 3D FMP SPGR sequence with the following parameters (TR: 26 ms, TE: 6.9 ms, flip angle 40 °, field of view 36 × 36 cm, matrix 246 × 256, 1 excitation). Gadolinium 0.3 mmol/kg was administered and 60 1.5-mm-thick partitions were obtained over a duration of 3.5 min. The MRA images were then compared with conventional digital subtraction angiography (DSA) images. Conventional DSA demonstrated 138 renal arteries, whereas gadolinium-enhanced MRA demonstrated 129 (93 %). Twenty-one renal artery stenoses and four occluded arteries were seen at conventional DSA. Gadolinium-enhanced MRA had a sensitivity of 88 %, specificity of 98 %, accuracy of 96 %, positive predictive value of 92 % and negative predictive value of 97 % when compared with conventional DSA. Gadolinium-enhanced MRA is an accurate technique for identifying patients with RAS. It is less sensitive in picking up accessory renal arteries. Received: 17 March 1998; Revision received: 30 June 1998; Accepted: 28 August 1998     

Comparison of magnetic resonance angiography,magnetic resonance imaging and conventional angiography in cerebral arteriovenous malformation

Summary 10 patients with an AVM of the brain were examined by magnetic resonance angiography (MRA), magnetic resonance imaging (MRI) and conventional cerebral angiography (CCA). From MRA in 7/10 patients important information about vascular supply could be provided; in 3 patients, all with small AVM's it could be only suspected. CCA revealed the vascularisation of the AVM's in all patients and showed additional hemodynamic aspects better than MRA. With MRI in all cases the AVM could be diagnosed, but only the involvement of the main cerebral vessels could be demonstrated; however, MRI is superior to MRA and CCA in showing the nidus and the involved brain structures.     

3.0TMRI常规序列及MRA对可逆性脑血管收缩综合征的诊断价值

目的：探讨 MRI 各序列与 MRA 对可逆性脑血管收缩综合征(RCVS)的诊断价值。方法回顾性分析明确诊断的5例RCVS 患者的临床资料和 MRI 及 MRA 显示的异常血管分布、形态、脑实质病变信号特点。结果5例 MRA 结果均显示颅内外大动脉呈非动脉硬化性、非炎症性、多发节段性狭窄与扩张,典型者呈“串珠样”改变,有4例并发颅脑病变,其中1例合并后部可逆性脑病综合征(PRES),局部皮层蛛网膜下腔出血1例,分水岭区脑梗死3例。5例治疗后3个月复查 MRI 及 MRA 完全恢复正常。结论MRI 及 MRA 能清楚显示脑血管形态,观察脑实质的继发性病变,对临床治疗和预后的评估具有重要的指导意义。     

Poststenotic signal attenuation on 3 D phase-contrast MR angiography: a useful finding in haemodynamically significant carotid artery stenosis

We performed blinded visual evaluation of MR angiography (MRA) films in 44 patients with unilateral carotid artery stenosis to determine whether a flow gap and poststenotic signal attenuation on 3 D-PC MRA were useful signs of severe carotid artery stenosis. Although nine patients with a flow gap alone had various degrees of stenosis ranging from 22.2 to 77.3 % without any decrease in regional cerebral blood flow (rCBF), 13 patients with both a flow gap and poststenotic signal attenuation had severe stenoses of 80 % or more, with a definite decrease in baseline rCBF. The presence of both a flow gap and poststenotic signal attenuation on 3 D-PC MRA appeared to be a reliable marker of severe carotid artery stenosis with a decrease in rCBF. Received: 30 April 1999/Accepted: 11 August 2000     

Magnetic resonance angiography of supratentorial tumours: comparison with selective digital subtraction angiography

We compared magnetic resonance angiography (MRA) and intra-arterial digital subtraction angiography (IADSA) in the study of brain tumours and assessed the utility of gadolinium-enhanced MRA. We studied 17 patients with supratentorial brain tumors. The entire brain was imaged with multiple overlapping thin volume acquisitions. After IV injection of gadolinium-DTPA, a single thick-slab MRA acquisition was performed. Standard three-dimensional (3D-TOF) acquisitions (in six patients) and 3D-TOF with magnetization transfer prepulse and tilted optimisation nonsaturing radiofrequency excitation pulses (in 11 patients) were used. Displacement of the anterior cerebral artery, main stem and insular branches of the middle cerebral artery was seen well on unenhanced and contrast-enhanced MRA. Displacement of the lenticulostriate and anterior choroidal arteries was seen only once, after Gadolinium. Tumour encasement of the middle cerebral artery was demonstrated in one patient. Tumour vessels were seen in 2 of 8 cases before and 3 of 8 after gadolinium; Tumour hypervascularity was seen only after gadolinium, in 3 of 8 cases. Study of the veins was possible only on gadolinium-enhanced MRA. Displacement of the venous angle was seen in 4 of 7 patients in the frontal, and in all of 8 patients on the lateral projections. Early venous drainage was not seen. Patency of the dural venous sinuses was demonstrated in all patients, but in one neoplastic occlusion of a cortical vein was recognised.     

Magnetic resonance angiography of extracranial carotid and vertebral arteries,including their origins: comparison with digital subtraction angiography

Summary Although carotid bifurcation stenoses are not the only lesions of the extracranial cerebral arteries, magnetic resonance angiographic (MRA) studies to date have concentrated on the carotid bifurcation. We compared digital subtraction angiography of the extracranial portions of the cerebral arteries with MRA using an ordinary body coil, the time-of-flight method, and multiple transverse slabs which covered the arteries down to the aortic arch. Twenty-two patients (15 with arteriosclerotic diseases, 4 with aortitis, and 3 with tumours) had MRA using a 1.5 T magnet system with a three-dimensional fast imaging with steady state precession (FISP) technique. Thirty-nine carotid and 39 vertebral arteries were assessed by three radiologists with regard to stenoses or occlusions, graded as normal, mild (<30%), moderate (30–60%) or severe (>60%) stenosis, or occluded. Grading corresponded well in 81%; stenoses appeared more marked on MRA in 14% and were seen less clearly on MRA in 5%. When 26 carotid bifurcations were assessed separately, grading corresponded well in 95%. MRA is the only method which can display the whole course of the extracranial carotid and vertebral arteries non-invasively and satisfactorily.