三维动态增强磁共振血流成像对指导肺癌手术的价值

目的：研究三维动态增强磁共振血流成像（3D DCE MRA）对肺癌侵犯血管的显示能力，探讨MRA术前对手术计划的指导价值。方法：肺癌患26例，除常规MR检查处，注射Gd-DTPA 0.2mmol/kg后，冠状面动态三维超快速梯度回波采集，最大强度投影法（MIP）重建。分析肺癌与血管的关系，与手术病理对照。结果：26例中25例肺部不同时相的血管显示清晰，9例肿瘤贴邻血管，另16例可见肿瘤粘连或包绕大血管。结论：3D DCE MRA可清晰显示肺段以上的肺动脉和肺静脉，对术前判断肿瘤能否切除及手术切除的范围有指导意义。     

4D-Flow-MRI在腹部血管血流动力学中的潜在应用价值

腹部的诸多疾病可以导致脏器血流动力学的异常。四维血流(4D-Flow)MRI不仅能够显示腹部血管床的血流分布,还能对血流动力学异常进行量化,是评估腹部血管血流动力学异常的重要工具之一。本文综述了4D-Flow-MRI的技术特点及其在腹部的潜在临床应用价值。     

磁共振在小儿常见骨关节疾病诊断中的应用

随着磁共振成像(MRI)技术的不断发展和完善,MRI在小儿骨关节病变诊断中逐渐显示出其特有的作用,有些方面是X线和CT无法比拟的。特别是一些疾病的早期阶段,MRI能对其定性诊断提供一些有价值的信息。     

三维动态增强磁共振腹部血管造影

目的：探讨三维动态增强磁共振腹部血管造影（3D-CE-MRA）成像技术和临床应用毒义。材料和方法：回顾性的分析了30例腹部3D-CE-MRA的成像技术和MRI表现。结果：全部病例显示良好。可以从不同的角度和位置上观察血管的整体形态。结论：三维动态增强磁共振腹部血管造影是腹部血管病变诊断的准确，快速，无创和首选的影像学检查方法，具有较高的临床应用价值。     

磁共振胰胆管成像在胰胆管疾病诊断中的应用价值

目的探讨磁共振胰胆管成像（MRCP）在胰胆管疾病诊断中的临床应用价值。方法采用重T2加权多次激发对100例临床拟诊胆道梗阻的患者进行MRCP检查,并经手术病理或其他影像学或临床资料证实。恶性梗阻28例,其中胰头癌9例,壶腹癌6例,胆管癌10例,原发性肝细胞癌直接侵犯3例;良性梗阻72例,其中胆总管结石33例,胆囊切除术后狭窄5例,胆囊炎或结石26例,慢性胰腺炎4例,先天性胆总管囊肿2例,硬化性胆管炎2例。结果 MRCP较清晰地显示了各种胰胆管疾病的部位和形态。本组定位诊断准确率为85%。MRCP的诊断敏感性为75%,特异性为83%,准确性为81%,阳性预测值为85%,阴性预测值为93%。结论 MRCP对于胆道梗阻性病变的定位较为准确,结合MRI平扫及资源像,定性诊断也有一定的特异性,是一种安全、无创的检查手段,能为临床诊治提供可靠依据。     

磁共振功能成像及其在脊椎疾病诊断中的应用

磁共振功能成像在脊椎良、恶性病变的鉴别中，通过分析影像信号、测量兴趣区的ADC值和灌注参数，可提供重要的诊断依据。     

磁共振成像对小儿中枢神经系统疾病的诊断价值

磁共振成像（ＭＲＩ）对头颅、脊柱、胸部、腹部、骨骼的检查已广泛开展。由于它对组织分辨率高，可直接显示血管，多参数成像，信息多，从而使临床有些疾病诊断过程得以简化，并且安全、可靠、无创伤、无Ｘ线损伤、图像清晰、定位准确，对早期病灶的发现阳性率高。小儿中...     

排泄性磁共振尿路成像在泌尿系疾病诊断中的价值

目的:探讨对比增强磁共振尿路成像(排泄性MRU)在诊断泌尿系疾病方面的价值.方法:选择经手术病理和影像学检查证实的泌尿系结石20例、肾盂旁囊肿6例、肾盏憩室1例、膀胱憩室3例和输尿管移行细胞癌4例,均先行磁共振尿路成像(常规MRU),然后增强扫描后延迟至5、10和20 min行排泄性MRU,显示不良者4 h后再扫描一次.将两者源图像分别进行最大强度投影(MIP)重组,并分别独立诊断,对两者结果进行对比分析.结果:排泄性MRU尿路显示清楚 5 min 5例,10 min 25例,4 h 4例.两者定位诊断符合率均为100%.排泄性MRU均能作出准确定性诊断,常规MRU准确定性诊断分别为泌尿系结石17例(17/20)、肾盂旁囊肿2例(2/6)、膀胱憩室3例(3/3)、输尿管移行细胞癌2例(2/4).结论:排泄性MRU能清楚显示尿路形态变化及、排泄功能,有利于尿路疾病的诊断.     

磁共振扩散成像在颅脑疾病诊断中的进展

随着磁共振扩散成像对脑缺血研究不断深入,人们对其在缺血性卒中诊断价值方面的认识也日趋完善,与此同时,扩散成像在神经系统其它疾病中的应用也逐渐被认识.对扩散成像技术方面的发展与现状及其在神经系统疾病中应用和进展进行综述,以利于指导临床更合理地应用扩散成像,对疾病进行诊断与治疗.     

腹部磁共振成像的应用和进展

近几年，随着磁共振设备硬件和软件技术的快速发展，MRI不但广泛应用于腹部实质脏器疾病的诊断，而且也越来越多地应用于空腔脏器疾病的诊断。对最近几年MRI在腹部重要脏器的应用和进展做了回顾和综述，以期对其做一较全面的认识和了解。     

增强MR血管造影在儿童先天性心脏病诊断中的应用

目的：评价儿童先天性心脏病（简称先心病）患者MRI检查，特别是增强磁共振血管造影术（CE－MRA）的诊断价值与不足。方法：300例儿童先天性患者作CE－MRA检查，其中173例228个心内结构异常和105个心外大血管异常已经手术证实，并与MRI及CE－MRA诊断结果作对照。结果：在228个手术证实的心内结构异常（主要为间隔缺损与瓣膜病变）中，196个诊断正确（86．0％）；在105个心外大血管异常中，101个诊断正确（96．2％）。结论：对心外大血管畸形MRI及CE－MRA有很高的诊断价值，CE－MRA是对先尽病最有价值的扫描方法之一。     

Head and neck haemangiomas: contrast-enhanced three-dimensional MR angiography

We evaluated the clinical effectiveness of contrast-enhanced three-dimensional (3D) magnetic resonance angiography (MRA) for diagnosing head and neck haemangiomas. We studied six patients using a magnetization prepared rapid acquisition gradient-echo (MP-RAGE) sequence on a 1.5-T system. Conventional T1- and T2-weighted and contrast-enhanced images were also obtained. The images were compared with histological findings. In four cavernous haemangiomas, a mass was partially visible as an enhancing lesion on the early phase of MRA, and was completely visible as a larger enhancing lesion in the late phase, showing slow blood flow. In two capillary haemangiomas, a mass was completely visible in the early phase showing fast flow. In all patients, MRA clearly showed both the haemangiomas and the external carotid artery branches. MRA allowed assessment of the relationship between the haemangiomas and the feeding arteries, and of the haemodynamics. Received: 17 April 1998 Accepted: 5 June 1998     

三维对比剂增强MR血管成像诊断布加综合征的价值

目的观察三维对比剂增强MR血管成像（3DCEMRA）上布加综合征（BCS）的各种表现,并初步评价该项新技术的价值。方法33例BCS患者行3DCEMRA检查。23例为继发性BCS,分别继发于肝细胞癌（21例）、右肾上腺癌（1例）或血栓性静脉炎（1例）。10例为原发性BCS。观察肝静脉、下腔静脉（IVC）和门静脉的开放性,观察有无肝内外侧支、肝实质病变和门静脉一体静脉间曲张静脉。10例患者行下腔静脉造影术,2例行肝右静脉穿刺造影术,把3DCEMRA所获的诊断结果与造影相对照。结果3DCEMRA可显示BCS的各种表现。肝静脉表现包括：癌栓形成（19例）、肿瘤压迫（2例）、肝静脉未显示（4例）和局限性狭窄（4例）。IVC表现为严重狭窄或闭塞（10例）、肿瘤直接侵犯（2例）、癌栓形成（3例）、血栓性静脉炎（1例）和隔膜形成（3例）。9例显示肝内侧支形成,其中2例显示“蜘蛛网”征象。所见的肝外侧支包括扩张的奇静脉和半奇静脉（13例）,以及左肾一膈下一心包膈静脉侧支（2例）形成。2例患者发现门静脉左支闭塞,10例患者发生门静脉．体静脉间静脉曲张。3DCEMRA发现的肝实质病变有：尾叶增大（7例）、不均匀强化（18例）和并发肿瘤（18例）。12例3DCEMRA诊断结果均与造影结果一致。结论3DCEMRA能显示BCS的各种征象,并能帮助提供正确诊断。     

腹主动脉瘤三维增强MR血管造影的临床价值

目的　评价三维增强磁共振血管造影 (3DCE MRA)及其重建技术在腹主动脉瘤 (AAA)检查中的临床价值。方法　 6 3例临床初诊为AAA的患者行 3DCE MRA及相关MR检查。 3DCE MRA用屏气超快速三维梯度回波序列 (3DFISP) [钆喷替酸葡甲胺 (Gd DTPA) 0 2mmol/kg ,1次扫描时间 18～ 2 0s],工作站上三维重建。观察AAA类型、形态、部位、附壁血栓及与分支血管的关系 ;近端瘤颈、远端流出道形态 ;并根据临床需要测量各部位长度、直径、角度 ;评价图像在制定治疗方案中的作用。结果　 6 3例AAA中 ,5 6例为肾下型 ,5例为近肾型 ,2例为肾上型。动脉瘤平均直径 5 3cm。 3DCE MRA能清楚显示动脉瘤类型、形态 ,近远端瘤颈情况及与分支动脉的关系。根据 3DCE MRA图像 ,临床选择合适的治疗方案。 6 3例中 31例行AAA血管内支架腔内隔绝术 ,3DCE MRA所测得的动脉瘤、近端瘤颈及远端流出道的长度及直径与DSA高度一致 (P >0 1) ;4例行传统人工血管置换术 ;另 2 8例因种种原因仅保守治疗。结论　 3DCE MRA因具有高诊断准确性、无放射性及肾毒性等优势 ,可作为AAA治疗前最主要的影像检查方法 ,具有极高的临床价值     

单倍剂量三维动态对比增强MR血管成像诊断肢体软组织血管瘤的价值

目的探讨单倍剂量三维动态对比增强MR血管成像（SD 3D DCEMRA）诊断肢体软组织血管瘤的可行性及其意义。方法测试30例健康志愿者注射单倍剂量钆喷替酸葡甲胺（Gd-DTPA）后Gd-DTPA至股、胭和胫前动脉中段的循环时间（TT）、动脉强化峰值信号强度（SPE）和动脉峰值强化持续时间（DPE）。45例肢体软组织血管瘤和9例神经鞘瘤行常规MRI和SD 3D DCEMRA检查，SD 3D DCEMRA扫描时间10～12S，获取动脉早、晚期及静脉期3期图像。观察、比较血管瘤常规MRI与SD 3D DCEMRA表现，比较血管瘤和神经鞘瘤SD 3D DCEMRA的差异。结果（1）股、胭及胫前动脉TT、SPE和DPE依次分别为（15±5）s、（400±50）、（11．9±2．6）s，（19±7）s、（320±45）、（16．8±3．6）s和（27±10）s、（270±39）、（22．0±6．6）s；3条动脉之间的TT（F=6．91，P〈0．01）、SPE（F=21．21，P〈0．01）及DPE（F=12．10，P〈0．01）差异有统计学意义。（2）血管瘤SD 3D DCEMRA表现：瘤体动态显现，自动脉早期至静脉期瘤体信号逐渐增强、瘤体显影范围增大，动脉早、晚期及静脉期平均瘤体信号分别为0．09、0.49和0．74，各期间差异有统计学意义（F=775．60，P〈0．01）；45例中，A型（动脉早期无显影）24例，B型（动脉早期轻微显影）21例，A型SD 3D DCEMRA3期平均瘤体信号0．43、B型0．46，差异无统计学意义（F=4．57，P〉0．01）。肿瘤供血动脉，显示率100％。（3）常规MRI上未能显示的2例血管瘤，SD 3D DCEMRA上动态显现瘤体和显示供血动脉。（4）神经鞘瘤SD 3D DCEMRA无瘤体动态显现和供血动脉显示。结论应用SD 3D DCEMRA诊断肢体软组织血管瘤是可行的，瘤体动态显现和供血动脉显示是其SD 3D DCEMRA特征。     

非增强MRA诊断下肢动脉病变的应用研究

目的：探讨QISS非增强MRA技术诊断下肢动脉闭塞性病变的临床应用价值。方法：51例下肢动脉病变患者行双下肢QISS-MRA和CE-MRA扫描,评价两种检查方法的图像质量,并以CE—MRA为参照标准,计算QISSMRA诊断下肢动脉显著性狭窄（≥50％）的敏感度、特异度、阳性预测值、阴性预测值和诊断准确性,并以配对χ2检验分析两种检查方法对诊断下肢动脉显著性狭窄（≥50％）的差异有无统计学意义,两种检查方法的相关性采用kappa检验。结果：51例中48例成功行QISS-MRA检查,其中图像质量优、良、差者分别为40（78．43％）、8（15．69％）和3例（5．88％）。按血管节段计算,QISS-MRA诊断下肢动脉显著性狭窄的敏感度和特异度分别为90．15％和98．87％,阳性预测值和阴性预测值分别为96．75％和96．42％,总体符合率为95．91％。对于下肢动脉显著性狭窄的诊断,QISS-MRA与CE-MRA的差异无统计学意义（χ2=3．76,P〉0．05）,且两种检查方法具有极好的相关性（r值为0．950,P〈0．001）。结论：QISS-MRA检查成功率较高、图像质量良好并且诊断效果接近CE—MRA,对诊断下肢动脉闭塞性病变有一定的临床应用潜力。     

Evaluation of the early enhancement of coronary atherosclerotic plaque by contrast-enhanced MR angiography

Purpose

To evaluate the early enhancement of coronary atherosclerotic plaque using contrast-enhanced MR angiography (CE-MRA) and investigate the association between unstable angina pectoris (UAP) and early enhancement of the plaque.

Methods

Forty-one patients presenting with angina pectoris and demonstrating single-vessel disease with non-calcified plaque and significant coronary stenosis (≥50%) on CTA were consecutively recruited for coronary CE-MRA. Contrast-to-noise ratio of the culprit plaque guided by CTA was measured on a cross-sectional multi-planar reconstruction image of the plaque on both pre- and post-CE-MRA. A 50% increasing of CNR was defined as plaque enhancement. The association between early enhancement of the plaques and UAP was analyzed.

Results

Thirty-seven non-calcified plaques with significant coronary stenosis were detected in the 37 patients on MRA. 4 subjects were excluded because coronary atherosclerotic plaques were inadequate for identification on MRA. Of the 37 patients, 18 patients had UAP and other 19 patients presented stable angina pectoris (SAP). Of the 37 plaques on CE-MRA, 13 and 24 plaques presented early enhancement and no enhancement, respectively. Of the 13 early-enhanced plaques, 11 (85%) and 2 (15%) were found in the patients with UAP and SAP, respectively (p < 0.01). Of the 37 patients, 11 (61%) with UAP and 2 (11%) with SAP had early-enhanced plaques, respectively (p < 0.01).

Conclusion

CE-MRA allows detection of early enhancement of coronary atherosclerotic plaque. The early enhancement is common in unstable angina and could be a sign of vulnerability.     

Preliminary evaluation of volume-rendered three-dimensional display of time-of-flight MR angiography in the diagnosis of intracranial aneurysms

We assessed the value of the volume-rendering method of displaying images of three-dimensional (3D) time-of-flight MR angiography (MRA) in the diagnosis of intracranial aneurysms. We obtained three-dimensional volume-rendered MRA from 21 patients with intracranial aneurysms. The images were evaluated in comparison with maximum-intensity-projection images (in 21 patients), conventional angiograms (in 21 ) and CT angiography (in nine). In 17 patients, 3D volume-rendered images were thought to show morphological features most clearly. They were superior to the other methods for demonstrating the precise location of the aneurysm in three patients and in showing the shape of the bleb in another three. 3D volume-rendered MRA can be effectively added to conventional imaging techniques for diagnosis of intracranial aneurysms. Received: 12 October 2000 Accepted: 12 December 2000     

Pelvic arteriovenous malformations: gadolinium-enhanced three-dimensional MR angiography findings

Pelvic arteriovenous malformations (PAVMs) are rare disorders traditionally diagnosed by conventional angiography. Breath-hold three-dimensional gadolinium-enhanced MR angiography (3D-Gd-MRA) is a state-of-the-art alternative for vascular imaging. We describe the 3D-Gd-MRA findings in two patients with PAVMs. The 3D-Gd-MRA approach provides a noninvasive and versatile method for evaluation of PAVMs that enables both angiographic assessment of the malformations and evaluation of visceral involvement, which can preclude surgical intervention. Received: 15 September 1999; Revised: 27 December 1999; Accepted: 27 December 1999     

Retrograde flow in the dural sinuses detected by three-dimensional time-of-flight MR angiography

Introduction Retrograde flow in the left dural sinuses is sometimes detected by three-dimensional time-of-flight (3D-TOF) magnetic resonance (MR) angiography. The purpose of this study was to evaluate the incidence of this phenomenon and its characteristic features on 3D-TOF MR angiograms. Methods We retrospectively reviewed cranial MR angiography images of 1,078 patients examined at our institution. All images were obtained by the 3D-TOF technique with one of two 1.5-T scanners. Maximum intensity projection (MIP) images in the horizontal rotation view were displayed stereoscopically. We reviewed the source images, inferosuperior MIP images, and horizontal MIP images and identified retrograde flow in the dural sinuses. Results We found retrograde flow in the dural sinuses of 67 patients on the source images from 3D-TOF MR angiography; the incidence was 6.2%. In 47 of the 67 patients, retrograde flow was identified in the left inferior petrosal sinus, in 13, it was seen in the left sigmoid sinus, and in 6, it was seen in the left inferior petrosal and left sigmoid sinuses. The remaining patient had retrograde flow in the left inferior petrosal and left and right sigmoid sinuses. The mean age of the patients with retrograde flow was slightly greater than that of the patients without this phenomenon (70 years vs 63 years). Conclusion Retrograde flow in the dural sinuses frequently occurs on the left side in middle-aged and elderly patients during 3D-TOF MR angiography performed with the patient in the supine position. This phenomenon should not be misdiagnosed as a dural arteriovenous fistula. This article was presented as an electronic poster paper at the 31st Congress of the ESNR held in Geneva in September 2006.