三维对比增强MR血管成像在颈部血管病变中的应用

目的探讨三维对比增强MR颈部血管成像（3D—CE—MRA）的方法及临床应用价值。方法对87例患者行颈部血管3D—CE-MRA检查,双日检查者采用testbolus＋3D—CE—MRA扫描,共检查49例患者,单日检查者采用carebolus＋3D—CE—MRA扫描,共检查38例患者,评价图像质量并分析病变血管情况．结果87例患者采用两种方法扫描图像质量无明显差异,均能满足临床诊断需要,3D—CE—MRA图像清楚显示了血管病变部何肢性质。结论3D—CE—MRA是无创、安全、便捷、可靠的颈部血管病变的检查方法,可以代替诊断性的DSA。     

三维增强MRA与多普勒超声诊断颈部血管病变的对照分析

目的探讨三维增强MRA及彩色多普勒超声对颈部血管病变的诊断价值。方法32例有眩晕、恶心、颈部不适等症状的患者均经三维增强MRA及多普勒超声检查。结果32例的36处病变节段中,超声检出19处,3DCEMRA检出33处。结论三维增强MRA对颈部血管病变的诊断能力优于多普勒超声,而高质量的颈动脉MRA图像依赖注药后扫描时机的准确性,注药流速与总量的合理性,合适的扫描序列,以及操作者的技巧和熟练程度。     

颈动脉三维增强磁共振血管成像技术初步探讨

目的　探讨颈动脉三维增强磁共振血管成像 (3DCEMRA)方法和影响图像质量的因素。方法　使用 1.5T超导型MR扫描机 ,头部、颈部以及部分腰椎相控阵线圈。对 48例病人进行颈动脉 3DCEMRA增强扫描。检查时 ,嘱患者屏气 ,于静脉内团注钆双胺 (Gd -DTPA -BMA)对比剂后进行颈动脉期扫描 ,用 3DFLASH序列采集图像。结果　检查的病例 96%获得了满意的图像 ,经MIP和MPR重建后 ,能够清楚显示颈动脉正常解剖结构和病变的部位、大小及其狭窄程度。 2 3例经数字减影血管造影(DSA)或 /和超声以及手术证实的病例中 ,3DCEMRA显示颈动脉的特异性和敏感性均为 10 0 %。结论　高质量的颈动脉MRA图像依赖于注药后扫描时机的准确性 ,注药流速与总量的合理性 ,合适的扫描序列 ,以及操作者的技巧和熟练程度     

三维动态增强MR血管成像的临床应用价值

目的 评价三维动态增强扫描MR血管成像(3D CEMRA)技术的临床应用价值. 资料与方法 评价3D CE MRA 对18例患者血管的显示情况. 结果 3D CE MRA 显示2例动脉狭窄或闭塞,2例静脉增粗、迂曲,5例显示血管瘤,3例血管畸形,1例右侧股骨下段骨肉瘤周边紊乱血管,5例正常. 结论 3D CE MRA可显示正常血管及异常.     

颌颈巨大肿物的颈动脉CTA和MRA的对比研究

目的对比分析颈动脉CT血管成像(CTA)和核磁共振血管成像(MRA)在头颈部的成像特点,探讨颈部巨大肿物对颈动脉正常解剖位置的影响和对血管壁侵蚀的价值。材料和方法术前对11例颌颈部肿物患者行颈动脉CTA和MRA,分别同步注射造影剂,螺旋CT对病变区血管段进行重点薄层螺旋扫描,EasyVision三维重建;MRI扫描由Sun工作站三维重建。对比分析颈动脉CTA和MRA。结果11例颌颈部肿物患者中5例颈总动脉、颈内动脉向内侧移位,其中2例颈外动脉受压狭窄;另1例颈内动脉向后侧移位,颈外动脉向外前移位;1例颈内静脉血管壁多处受侵蚀。结论CTA能够显示颈部大血管走向及与下颌骨、舌骨、颈椎、颅底骨组织三维空间关系;MRA显示血管壁的情况较CTA精确,均可为诊断和手术入路提供三维信息。     

3.0T MR多技术联合应用在头颈部动脉血管狭窄病变中的诊断价值

目的:分析3.0T MR 3D TOF MRA、高分辨CE MRA、双反转恢复颈动脉血管壁黑血成像在头颈部动脉血管狭窄病变检查中的技术特点,探讨其联合应用在头颈部动脉血管狭窄病变中的诊断价值。方法:研究所用技术经医院伦理委员会审查批准,向患者认真介绍后由患者签字同意。选择2009年5月~2009年6月在我院行头颈部TOF MRA检查患者95例,其中43例并行头颈部CE MRA检查,另52例并行颈动脉分叉部双反转恢复T2WI血管壁黑血成像。统计同时行TOF MRA和CE MRA患者组中两种技术完成的图像中脑血管、颈内动脉虹吸段、颈动脉分叉部、椎动脉起始部等多个部位动脉血管狭窄数量,对两种技术诊断结果行Kappa一致性检验。统计同时行TOF MRA和DIR颈动脉分叉部血管壁黑血成像患者组中狭窄血管数量,对两者行χ2检验判断有无统计学差异。结果:行头颈部TOF MRA和CE MRA患者组,各部位诊断结果Kappa值分别为:大脑前动脉A1段0.710,大脑中动脉M1段0.823,大脑后动脉P2段0.672,颈内动脉虹吸段0.729,颈动脉分叉部0.634,椎动脉起始部0.707。行头颈部TOF MRA和颈动脉分叉部DIR T2WI黑血血管壁成像患者组,两者诊断结果χ2=1.11,P0.05,无统计学差异。结论:3D TOF MRA和CE MRA技术均可明确诊断绝大部分头颈部动脉血管狭窄病变,但也有各自的不足,颈动脉血管壁黑血成像可明确诊断有无粥样硬化斑块形成,是对头颈部MRA成像的有效补充,三者的合理应用及结合可以从多方面来诊断头颈部血管狭窄性病变,弥补相互间的不足。     

16排CT诊断颈动脉狭窄病变的应用价值

目的：探讨16排螺旋CT颈动脉成像（CTA）的临床应用价值。方法：对颈动脉支配区脑梗死的住院患者行16排螺旋CT颈动脉成像检查，采用VR、MIP、SSD和VE技术重建三维颈动脉图像。结果：正常4例，异常30例，共观察颈动脉68支，其中正常血管25支，狭窄血管43支。16排螺旋CT颈部血管成像能清楚显示颈部血管，对决大部分的颈部血管狭窄能迅速，准确的诊断。结论：螺旋CT、CTA检查是一种显示颈部血管狭窄病变有价值的检查方法，对怀疑颈动脉狭窄的进行筛查及临床治疗方案的制定有重要的指导作用。     

下肢周围动脉闭塞性疾病病人行心电图触发非对比增强MR血管成像(TRANCE)和数字减影血管造影(DSA)的对比研究

目的对心电触发非对比增强MR血管成像(TRANCE)和数字减影血管造影(DSA)诊断下肢(包括足部)周围动脉闭塞的诊断价值进行前瞻性对比研究。方法43例有症状的周围动脉闭塞疾病(PAOD)病人在DSA检查前进行TRANCE检查。将MR血管成像(MRA)显示下肢     

磁共振血管成像在脑血管病中的诊断价值

目的:探讨三维时间飞跃法MR血管成像(3D TOF MRA)和三维增强MR血管造影(3D CE-MRA)检查技术,评价两种方法对脑血管病的诊断价值。方法:磁共振血管成像检查150例,全部行3D TOF MRA检查;9例进行3D CE-MRA检查,钆对比剂(Gd-DTPA)0.2mmol/kg,注射流率3ml/s,增强前、增强后动脉期及静脉期3次扫描;所有MRA图像进行三维重建,同期12例行DSA检查。常规MRI包括横断面T1WI、T2WI,矢状面T1WI。结果:56例中颅内血管显示正常56例,颅内动脉狭窄或闭塞者46例,颅内动脉瘤22例,颅内动静脉畸形21例,颈内动脉海绵窦瘘3例,烟雾病(moyamoya dis-ease)2例。结论:3D TOF MRA和3D CE-MRA是无创、快速、有效的检查技术,对诊断脑血管病有较高的价值,结合原始图像和常规MRI检查,一次检查即能为临床提供较为全面的信息,可作为脑血管病的筛选和首选诊断方法。     

颅内动脉粥样硬化性狭窄高分辨磁共振成像

常规血管影像学检查如CT血管成像(CT angiography,CTA)及MR血管成像(MR angiography,MRA)等能直接显示颅内动脉管腔情况,但不能显示管壁结构[1]。高分辨率磁共振成像(high-resolution MRI,HRMRI)已经用于颅外颈动脉     

透视触发并行采集高分辨率三维增强颈动脉磁共振血管成像术

目的评估透视触发和并行采集技术用于高分辨率三维增强颈动脉磁共振血管成像术(3DCEMRA)的可行性。方法80个临床诊断或怀疑颈动脉狭窄的病人接受3DCEMRA检查。使用透视触发软件触发启动颈动脉3DCEMRA扫描,同时采用K空间椭圆形中心填充法和加速因子为2的并行采集技术。对显示的各段动脉和有无静脉早期显影做分析。动脉狭窄分成动脉管壁不规则、轻度狭窄、严重狭窄和闭塞。颈动脉3DCEMRA的显示结果与其他检查结果做了对照。结果所有病例均顺利触发和完成颈动脉3DCEMRA检查。3DCEMRA显示了80例病人总共800支动脉段(100%显示率),所有病例在动脉显示区域内静脉均未显影或显影很淡,对诊断不构成影响。结果显示有680段动脉正常、41段动脉管壁不规则、24段动脉轻度狭窄、51段严重狭窄和4段闭塞。另外10段颈动脉狭窄处溃疡形成,12例患者除见颈动脉狭窄以外,还发现合并椎动脉和/或锁骨下动脉狭窄。36例病例,与其他血管成像技术作了比较,3DCEMRA的检查结果与之完全符合,未出现高估或低估血管狭窄程度。结论透视触发并行采集高分辨率3DCEMRA简单可行,成像时间短,空间分辨率高,能清楚显示颈动脉,它将在颈动脉狭窄的诊断中起重要作用。     

MR angiography of the carotid arteries: parameters affecting image quality

RATIONALE AND OBJECTIVES: This study was performed to evaluate the relationship between dose levels of contrast medium and image quality in magnetic resonance (MR) angiography of the carotid arteries with fluoroscopically monitored, manually triggered, elliptically ordered image acquisitions. MATERIALS AND METHODS: Twenty-five patients with clinical indications for angiography of the carotid arteries were examined with MR at 1.5 T by using a fluoroscopically monitored, manually triggered, elliptically ordered pulse sequence with the administration of one of three different volumes of gadolinium-based contrast medium. The signal intensities of the vessel lumen and the surrounding tissues were measured in single partitions at the origin of the common carotid artery, the carotid bifurcation, and the intracranial internal carotid arteries. The contrast-to-noise ratio in these regions of interest also was measured. Maximum intensity projection image quality was appraised for blurring, artifacts, venous enhancement, background suppression, and contrast medium distribution. RESULTS: No artifacts or venous enhancement was observed. The position of the fluoroscopic section affected the distribution of contrast medium along the vessel, as evidenced by the difference between the contrast-to-noise ratio at the origin of the common carotid artery and the ratio at the carotid bifurcation and the intracranial internal carotid arteries (P < .01). The contrast medium dose administered was strongly correlated with image quality (r = 0.90). CONCLUSION: Contrast medium dose is related to image quality in MR angiography of the carotid arteries performed with elliptical ordering, fluoroscopic monitoring, and manual triggering.     

肺栓塞的磁共振成像技术应用研究

目的探讨MR I透视触发造影剂团跟踪和动态增强磁共振血管成像(DCE-MRA)扫描技术在肺灌注和肺动脉血管造影中的应用价值。方法8例疑有肺栓塞的患者,应用MR I透视触发造影剂团跟踪和DCE-MRA扫描技术,行肺动脉血管造影和肺灌注成像。结果8例均成功进行肺动脉血管造影和肺灌注扫描,其中2例正常,6例发现肺动脉血栓形成,并有明确动态显示的局部肺叶灌注异常。结论MR I透视触发造影剂团跟踪和DCE-MRA扫描技术的应用,可1次注射造影剂既发现了肺动脉内血栓,又可显示肺内灌注缺损,是较好的肺栓塞诊断方法。     

肾动脉纤维肌层发育不良的高分辨力三维增强MR血管成像

目的:评价高分辨力三维增强磁共振血管成像术(3D CE MRA)诊断肾动脉纤维肌层发育不良(FMD)的价值.方法:5例经临床和DSA造影确诊的肾动脉FMD患者行肾动脉高分辨力3D CE MRA检查,扫描同时使用透视触发和并行采集技术.分析所有患者的肾动脉和FMD显示情况,并与DSA对照.结果:肾动脉3D CE MRA清楚显示5例患者10支肾动脉主干及其近端段级分支,且静脉均未显影或显影很淡.5例FMD均为单侧肾动脉受累,2例表现为肾动脉主干和近端段级分支串珠状改变,3例表现为肾动脉中段局限性狭窄.3D CE MRA显示结果与DSA一致.结论:高分辨力肾动脉3D CE MRA能较好检出肾动脉主干和近端分支的FMD.     

肾动脉高分辨力三维增强磁共振血管成像术:透视触发和并行采集技术使用初探

目的:评估透视触发和并行采集技术用于肾动脉高分辨力三维增强磁共振血管成像术的可行性和对肾动脉的显影诊断效果。方法:90例临床诊断或怀疑肾动脉或腹主动脉病变的患者行高分辨力肾动脉三维增强磁共振血管成像(3D CE MRA)。使用透视触发软件启动肾动脉3D CE MRA扫描,扫描采用K空间中心填充法和加速因子为2的并行采集技术。分析图象质量和病变显示情况,并与其它检查结果对照。结果:肾动脉3D CE MRA显示了90例患者共810支动脉段(100%显示率),平均显示等级为3.88。3D CE MRA显示8例11支副肾动脉,显示等级均为4.0。肾动脉段级分支的显示率为73%(66/90例)。所有病例在动脉显示区静脉均未显影或显影很淡,平均等级为0.20。3D CE MRA发现639支动脉段正常;66支动脉段管壁不规则;55支动脉段轻度狭窄;37支动脉段严重狭窄;2支动脉段闭塞;11支动脉段动脉瘤形成。其中96支肾动脉存在狭窄,11支副肾动脉均正常。共有43例病例,肾动脉3D CE MRA与其它血管成像技术作了比较,3D CE MRA的检查结果与之完全符合。结论:透视触发并行采集肾动脉高分辨力3D CE MRA简单可行,成像时间短,空间分辨力高,能清楚显示肾动脉且无静脉污染。     

磁共振Keyhole技术在颈动脉动态增强血管成像中的应用

目的　探讨匙孔 (Keyhole)技术在颈动脉动态增强磁共振血管成像 (dynamiccontrastechancedMRA ,DCE -MRA)中的应用优势。方法　将疑有颈部动脉疾病的 16例患者分为 2组 ,实验组 8例患者使用Keyhole技术 ;对照组 8例未使用Keyhole技术 ,直接行DCE -MRA扫描。结果　对照组 8例患者中 2例扫描在 6～ 8s时 ,只有动脉显示 ,而静脉未显影 ,3例扫描时间 8～ 9s时 ,已有静脉轻微显影。 3例扫描时间 >10s时 ,静脉已完全显影。实验组的 8例患者由于扫描时间缩短了一半 ,8例均获得了清晰、立体的颈动脉血管及分支全貌且无静脉显示的图像。结论　Keyhole技术的使用大大地缩短了扫描时间 ,可使颈动脉图像快速显影 ,不受静脉同时显示的干扰 ,提高了诊断准确性     

Carotid arteries: maximizing arterial to venous contrast in fluoroscopically triggered contrast-enhanced MR angiography with elliptic centric view ordering

PURPOSE: To obtain high-spatial-resolution, venous-suppressed, contrast material-enhanced, three-dimensional (3D) magnetic resonance (MR) angiograms of the carotid arteries and aortic arch by using an elliptic centric view ordering with MR fluoroscopic triggering. MATERIALS AND METHODS: Forty consecutive patients with cerebrovascular disease in the differential diagnosis were evaluated with fluoroscopically triggered 3D MR angiography (gadoteridol dose range, 0.1-0.3 mmol per kilogram of body weight; mean acquisition time, 40 second +/- 8 [SD]). The contrast-enhanced 3D MR angiograms were evaluated for overall quality, vascular signal intensity, venous suppression, and motion artifact. Twenty patients also underwent two-dimensional (2D) time-of-flight (TOF) MR angiography. The overall quality of the 2D TOF MR angiograms and comparative quality between the 2D TOF and contrast-enhanced 3D MR angiograms were determined. RESULTS: The contrast-enhanced 3D MR angiograms were of excellent or more than adequate quality for diagnosis in 36 of the 40 studies (90%). In 35 of the 38 contrast-enhanced 3D studies in which the contrast material bolus was detected fluoroscopically, the internal jugular vein signal intensity was either not detectable or barely visible. In 18 of the 20 patients who also underwent 2D TOF MR angiography, the quality of the contrast-enhanced 3D MR angiograms was graded as markedly superior or superior. CONCLUSION: Contrast-enhanced, elliptic centric 3D MR angiography with real-time MR fluoroscopic triggering offers high-spatial-resolution images of the carotid arteries and aortic arch with reliable venous suppression.     

High-resolution contrast-enhanced magnetic resonance angiography of the carotid arteries using fluoroscopic monitoring of contrast arrival: diagnostic accuracy and interobserver variability

Purpose: To evaluate the diagnostic accuracy of high-resolution contrast-enhanced magnetic resonance angiography (CE-MRA) of the supra-aortic arteries using the CareBolus technique. Digital subtraction angiography was the standard of reference. Material and Methods: Fifty consecutive patients with suspected internal carotid artery stenosis underwent CE-MRA and digital subtraction angiography. CE-MRA was performed on a 1.5-T superconducting scanner with the CareBolus technique. CareBolus combines a nearly real-time 2D-FLASH (fast low angle shot) sequence for fluoroscopic triggering and a high-resolution 3D-FLASH with elliptical centric view order for the angiographic pulse sequence (6.0/2.16 ms [TR/TE], 30° flip angle, 30.98 s acquisition time, 0.88 mm effective (interpolated) partition thickness and a 160×512 matrix). Intra-arterial digital subtraction angiography and CE-MRA studies were evaluated independently by four blinded readers. Internal carotid artery stenoses were graded according to the NASCET criteria. Results: CE-MRA had an accuracy of 92.53%, a sensitivity of 95.64%, and a specificity of 90.39% for the identification of carotid artery stenoses ≥70% (grade 3). Image quality for suppression of stationary tissue and venous contrast was good, but was reduced in five cases due to patient motion. Conclusion: The CareBolus technique is a useful non-invasive method for high-resolution imaging of the supra-aortic vessels because of its easy application and high sensitivity and specificity. Limitations can occur in non-compliant patients due to motion artifacts during the measurement time.     

动态增强磁共振血管成像技术及应用优势

目的 探讨动态增强磁共振血管成像(DCE MRA)技术要点及临床应用优势。资料与方法 对35例疑有血管性病变的患者，行DCEMRA扫描，最大信号强度投影(MIP)重建。结果35例均获得了清晰的血管图像，其中8例正常，27例异常。结论 DCE MRA为新的MRA技术，克服了常规MRA及对比增强MRA的缺点，成像效果与DSA相仿，因此具有极大的临床应用价值。     

追踪触发技术在颅颈联合CTA中的应用研究

目的:探讨追踪触发技术在多层螺旋CT颅颈联合动脉成像中的应用。方法:扫描设备为飞利浦MX8000四层螺旋CT机。11例进行同层动态增强扫描,绘制时间密度曲线,以探讨触发技术的理论阈值。以理论阈值为中心,将30例志愿者随机分为3组(阈值分别为65HU、75HU及85HU)探讨追踪触发技术的应用阈值。结果:阈值65HU组,扫描起始处颈总动脉的CT值较低(均数98HU);阈值85HU组,扫描起始处动脉显示好,但颈内动脉C1段的CT值较低(均数142HU),与同层静脉的密度对比明显降低;阈值75HU组,靶血管全程的CT值均与参考标准(150-200HU)一致,动静脉密度对比明显,后处理的动脉图像清晰。结论:①颅颈联合MSCTA可系统显示头颈部血管,避免分段成像的遗漏或不必要的重复、追加扫描。②追踪触发技术在更好地显示靶血管的同时,省去了小剂量试验,减少了对比剂用量,更加简便快捷。对比剂注速3.5 ml/s,触发阈值为75HU时的图像质量较佳。