动态增强MRA的实验研究

目的：通过动物实验来评估动态增强ＭＲＡ（ＤＣＥ ＭＲＡ）潜在的临床价值。材料与方法：选择６条狗同时行２Ｄ ＴＯＦ ＭＲＡ和ＤＣＥ ＭＲＡ检查，以ＤＳＡ图像为黄金标准，比较两者对不同部位血管的显示满意率。结果：２Ｄ ＴＯＦ ＭＲＡ和ＤＣＥ ＭＲＡ的显示满意率，主动脉弓及弓上分支分别为２２．２％和１００％，颈、椎动脉分别为７０％和７５％，腹主动脉及肾动脉分别为６６．７％和２６．７％，髂、股动脉分别为８     

颈内—后交通小动脉瘤的3D PC MRA评价

评价三维相位对比法磁共振血管成像（３Ｄ ＰＣ ＭＲＡ）显示颈内－后交通小动脉瘤的能力。材料和方法，对８例疑颅内血管性病变患者在ＧＥ Ｖｅｃｔｒａ０．５Ｔ超导系统上进行３Ｄ ＰＣ ＭＲＡ检查，并与ＣＡＧ／ＤＳＡ结果对照，以矢状在ＳＥＴ１ＷＩ为定位像，采用最短ＴＥ、３０－４０ｃｍ／ｓ的编码流速等参数运用３ＤＰＣ法，采集范围包括颈内动脉虹吸部和Ｗｉｌｌｉｓ图像进行分析。结果：经ＣＡＧ／ＤＳＡ证实右侧颈内     

烟雾病的磁共振成像诊断

目的：回顾分析８例烟雾病的磁共振成像表现，探讨磁共振成像对烟雾病的诊断价值。方法：８例烟雾病中男女各４例。年龄４～４９岁，平均２０．４岁。磁共振成像应用Ｓｉｅｍｅｎｓ１．０ＴＭＲ系统和头表面线圈。均有ＳＥ序列Ｔ１ＷＩ和Ｔ２ＷＩ，７例有三维时间飞跃法磁共振血管造影（３Ｄ－ＴＯＦＭＲＡ），１例有ＤＳＡ。结果：ＳＥ序列ＭＲＩ均见丘脑－基底节区（单侧２例，双侧６例）有扩张的烟雾血管，其中以Ｔ１ＷＩ显示更为清楚直观。７例３Ｄ－ＴＯＦＭＲＡ和１例ＤＳＡ均见ＩＣＡ上端、ＭＣＡ和ＡＣＡ近端闭塞以及丘脑－基底节区的烟雾血管。这些病理血管分布侧别与ＳＥ序列磁共振成像所见一致。结论：ＳＥ序列磁共振成像和３Ｄ－ＴＯＦＭＲＡ是诊断烟雾病的有效方法。Ｔ１ＷＩ显示丘脑－基底节区烟雾血管优于Ｔ２ＷＩ。３Ｄ－ＴＯＦＭＲＡ尚适用于烟雾病血管旁路术后随诊及其高危人群普查。     

磁共振胰胆管成像的临床应用研究

目的：评价磁共振胰胆管成像（ＭＲＣＰ）的临床应用价值。材料与方法：在Ｐｈｉｌｉｐｓ ＧｙｒｏｓｃａｎＴ１０－ＮＴ１．０超导型磁共振成像仪上进行ＭＲＣＰ检查５８例,其中作为正常对照组１６例,各种胰胆管病变者４２例。ＭＲＣＰ采用不屏气涡轮自旋回波（ＴＳＥ）序列的重度Ｔ２加权像扫描（ＴＲ／ＴＥ＝２０００ｍｓ／７００ｍｓ）,并应用呼吸触发及脂肪抑制技术。图像后处理以最大强度投影法（ＭＩＰ）进行三维（３Ｄ）     

胰胆管疾病的磁共振胰胆管成像与内窥镜逆行胰胆管造影初…

目的：探讨磁共振胰胆管成像（ＭＲＣＰ）对胰胆管疾病的临床应用价值。材料与方法：２０例高度怀疑胰胆管疾病的患者均经内窥镜逆行胰胆管造影（ＥＲＣＰ）和ＭＲＣＰ检查，并将ＭＲＣＰ影像与ＥＲＣＰ影像进行非双盲对照分析，其中１５例经手术证实。ＭＲＣＰ采用屏气、一次激发半傅立叶转换快速自旋回波序列（ＦＡＳＥ）、重Ｔ２加权、二维（２Ｄ）多个平面成像技术。结果：冠状位ＭＲＣＰ图像与ＥＲＣＰ图像极其相似，ＭＲＣＰ图     

颈内－后交通小动脉瘤的3D PC MRA评价

目的：评价三维相位对比法磁共振血管成像（３ＤＰＣＭＲＡ）显示颈内－后交通小动脉瘤的能力。材料和方法：对８例疑颅内血管性病变患者在ＧＥＶｅｃｔｒａ０．５Ｔ超导系统上进行３ＤＰＣＭＲＡ检查，并与ＣＡＧ／ＤＳＡ结果对照。以矢状面ＳＥＴ１ＷＩ为定位像，采用最短ＴＥ３０～４０ｃｍ／ｓ的编码流速等参数运用３ＤＰＣ法，采集范围包括颈内动脉虹吸部和Ｗｉｌｌｉｓ环血管的三个血液流动轴向（上／下、左／右、前／后）上的血流信号，最后对单／双侧叠加、旋转和矩阵重组形成的血管投影图像进行分析。结果：经ＣＡＧ／ＤＳＡ证实右侧颈内－后交通小动脉瘤５例，左侧３例，外形上以囊袋状为主，其中２例呈葫芦状，瘤体平均直径约６．５ｍｍ。３ＤＰＣＭＲＡ均满意显示动脉瘤的位置和大小，但瘤颈和瘤体外形的勾画不及ＣＡＧ／ＤＳＡ，且瘤体内信号强度较相邻动脉血管为低。结论：３ＤＰＣＭＲＡ虽然不能完全取代ＣＡＧ／ＤＳＡ，但对颈内－后交通小动脉瘤的评价显示出生命力，可作为对高危颅内动脉瘤患者进行筛选的有力工具。     

尿转铁蛋白在糖尿病肾病早期诊断中的价值

采用激光免疫比浊法测定７５例非胰岛素依赖型糖尿病（ＮＩＤＤＭ）病人尿转铁蛋白排泄率（ＵＴＥＲ）。结果表明：临床蛋白尿组及微量白蛋白尿组ＵＴＥＲ升高率分别为１００％、９６２％，而在尿白蛋白正常组，ＵＴＥＲ升高率仍可达２５０％，与尿白蛋白排泄率（ＵＡＥＲ）升高率比较，差异有非常显著意义（χ２＝７１，Ｐ＜００１）。提示尿ＵＴＥＲ确为更敏感的糖尿病肾病早期诊断指标     

三维增强磁共振肺动脉血管造影诊断肺动脉血栓栓塞

目的 探讨三维增强ＭＲ肺动脉血管造影（３Ｄ ｃｏｎｔｒａｓｔ－ｅｎｈａｎｃｅｄ ＭＲ ｐｕｌｍｏｎａｒｙ ａｎｇｉｏｇｒａｐｈｙ,３Ｄ ＣＥＭＲＰＡ）诊断肺动脉血栓栓塞的价值。方法 肺动脉栓塞患者１２例,共行１７次３Ｄ ＣＥＭＲＰＡ,其中４例５次于３Ｄ ＣＥＭＲＰＡ当天进行了选择性肺动脉ＤＳＡ。静脉注射钆喷替酸葡甲胺０．２ｍｍｏｌ／ｋｇ后,屏气获得２４层肺血管连续冠状面像,以最大强度投影法（ＭＩＰ     

高压氧间断暴露及氧惊厥对大鼠抗氧化酶活力及脂质过氧化物含量的影响

目的：为研究高压氧暴露对机体抗氧化酶系统的影响，本实验观察了高比氧间断暴露及氧惊厥条件下，大鼠红细胞、肺和肝组织中抗氧化酶（ＳＯＤ、ＧＳＨｐｘ、ＣＡＴ）活力及作为脂质过氧化物（ＬＰＯ）指标的丙二醛（ＭＤＡ）的含量的变化。方法：３８只雄性ＳＤ大鼠随机分组为：常压空气对照组（ｎ＝１２）；０．３ＭＰａＮ＿２－Ｏ＿２（ＰＯ＿２＝２１ｋＰａ）组（ｎ＝６）与０．３ＭＰａＯ＿２组（ｎ＝１２），暴露时间均为每天３０分钟，连续１０天；氧惊厥组（ｎ＝８）为０．６ＭＰａＯ＿２暴露１５分钟１次。结果：０．３ＭＰａＯ＿２，及０．３ＭＰａＮ＿２０Ｏ＿２两组组织中ＳＯＤ、ＧＳＨｐｘ、ＣＡＴ的活力及ＭＤＡ含量没有显著变化；０．６ＭＰａＯ＿２氧惊厥组，红细胞中ＧＳＨｐｘ活力与对照相比显著下降（Ｐ＜０．０５），而红细胞及肝组织中的ＭＤＡ含量则显著升高（Ｐ＜０．０５），但ＳＯＤ及ＣＡＴ活力无明显变化。结论：本实验中高压氧间断暴露方式对机体没有明显损害作用；氧中毒时ＧＳＨｐｘ活力易受抑制为抗氧化酶防御系统中的薄弱环节。     

冠状动脉搭桥术后磁共振桥血管成像的初步探讨

目的 以ＭＲ成像评价桥血管开通及功能,探讨适用于国人冠状动脉搭桥（ＣＡＢＧ）术后的影像学随访手段,方法 用１．５ＴＭＲ机检查２７例ＣＡＢＧ术后患者的７４支桥血管,行屏气快速场回波（ＦＦＥ）序列扫描观察桥血管的开通。其中１６例４２支桥血管行相位对比磁共振血流成像（ＰＳＭＲＡｆｌｏｗ）,得出血流速度和流量曲线,对桥血管的开通进行再评价。结果 本组桥血管ＦＦＥ成像开通率为８９．２％（６６／７４）。以ＰＳ     

三段移床三维增强MRA在腹盆及下肢血管病变中的应用

目的　探讨三段移床三维增强MRA 1次全程显示腹盆及下肢血管树的技术及其在血管病变诊断中的作用。方法　 12例腹盆及下肢血管病变的患者 ,男 8例 ,女 4例。 10例同时做了动脉和静脉成像 ,其中动脉血栓形成 5例 ,动脉硬化性闭塞性脉管炎 6例 ,静脉血栓形成 7例 ,下肢静脉炎 3例。其中 5例经DSA证实 ,5例手术证实。扫描序列采用三维快速SPGR序列 ,移床三段扫描。结果　靶血管显示优 9例 ,良 3例。有手术或DSA结果 10例中 ,共有病变段 3 4段 ,其MRA诊断与DSA或手术符合率为 85 .3 %。结论　移床三维增强MRA能使腹主动脉及两侧髂动脉分叉到小腿动脉全程显影 ,还可显示静脉。侧枝循环情况显示优于DSA ,是一种前途广阔的简便的血管检查新方法。     

Evaluation of MR angiographic technique in the assessment of thoracic outlet syndrome

AIM: To evaluate two-dimensional time of flight (2D TOF) and three-dimensional contrast-enhanced magnetic resonance angiographic (3DCE MRA) techniques in the assessment of patients with suspected thoracic outlet syndrome (TOS) of vascular origin. MATERIALS AND METHODS: Fifty-five consecutive examinations, in 51 patients with suspected TOS of vascular origin, were examined using either a 1T or 1.5T Siemens magnetic resonance imaging (MRI) unit, using either 2D TOF (n=13) or 3DCE MRA (n=42). Examinations were performed with the arms abducted (n=27) or both abducted and adducted (n=28). The source images and MIPs were reviewed retrospectively and assessed for image quality and the presence of significant persistent stenosis or impingement (a >60% reduction in the diameter of the subclavian vessels at the thoracic outlet or evidence of post-stenotic dilatation). When significant impingement was identified, the images were reformatted with multiplanar reconstruction to determine the cause. RESULTS: Images were sub-optimal in 53% 2D TOF and 10% 3DCE MRA examinations. 3DCE MRA offered vessel coverage from the aortic arch to the distal axilliary arteries, whereas, 2D TOF sequences gave more limited coverage. Eight patients were found to have significant impingement (n=7) or stenosis (n=1) of the subclavian artery attributable to TOS. 3DCE MRA also demonstrated other relevant significant stenoses not attributable to TOS (n=5). All cases of impingement were either seen only, or more prominently, on sequences with the arms abducted. Reformatting the 3DCE MRA studies demonstrated the cause of impingement. CONCLUSIONS: Both 2D TOF and 3DCE MRA may demonstrate TOS with significant arterial impingement. In comparison with 2D TOF sequences, 3DCE MRA offers extensive vessel coverage, is less prone to artefact and frequently demonstrates the underlying cause of TOS when studies are reformatted. Evidence of impingement should be sought from sequences performed with the arms abducted and venous phase sequences may show corroborative venous impingement.     

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。     

脑血管狭窄与闭塞的MRA与DSA对照研究

目的：评价ＭＲＡ诊断脑血管狭窄与闭塞的价值又限度，并对假阳性、假阴性进行分析。材料与方法：对１４例患者的１２０根正常、狭窄与闭塞血管进行３Ｄ－ＴＯＦ ＭＯＴＳＡ ＭＲＡ和ＤＳＡ对照分析。结果：１４例１２０根血管ＭＲＡ与ＤＳＡ诊断相符合血管数为１０９根（９０．８％），ＭＲＡ对正常脑血管的敏感性、特异性、准确性分别为９１％、９０．３％、９０．８％；对狭窄血管分别为８３．３％、９２．１％、９０．８％；对     

MRA在腹部静脉的应用

目的：评价常规ＭＲＡ和动态增强ＭＲＡ在腹部静脉检查中的价值。材料与方法：腹部静脉ＭＲＡ共５７例行５９人次检查。包括２Ｄ ＴＯＦ５１次，２Ｄ ＰＣ１９次，动态增强ＭＲＡ３０次（其中２Ｄ动态增强１０次，３Ｄ动态增强２０次）。５７例中门脉高压者１８例，布加氏综合征８例，门腔静脉分流术前或术后检查６例，原发性和转移性肝癌９例，其他病变６例，正常组１０例。结果：本组ＭＲＡ表现分别为门脉增粗和静脉曲张；下腔静     

MR angiography in carotid stenosis: A comparison of three techniques

Purpose: To compare the accuracy of three different magnetic resonance angiography (MRA) techniques for studying steno-occlusive disease of carotid arteries. Methods: 64 patients were evaluated with three MRA techniques- three-dimensional (3D) time-of-flight (TOF), two-dimensional (2D) TOF, and 3D Phase-Contrast (PC); the acquisition was in the axial plane, the volume included the carotid bifurcation. Digital subtraction angiography (DSA) was considered the `gold standard'. The MRA images were reprojected with a maximum intensity pixel ray-tracing (MIP) algorithm. The three MRA techniques were blindly graded as normal, mildly stenotic (0–29%), moderately stenotic (30–49%), severely stenotic (70–99%), or occluded. Results: DSA provided 128 diagnostic judgments: 92 were negatives and 36 positives. 2D TOF was in agreement with angiography in 116 of 128 cases (90%), but overestimated the results in seven cases and underestimated in five cases. 3D TOF agreed with angiography in 125 of 128 cases (97%), with one overestimation and two under estimations. 3D PC was concordant in 116 of 128 cases (90%), overestimating in six cases, underestimating in six cases. The sensitivity, specificity and diagnostic accuracy for 2D TOF was, respectively 84%, 94%, and 92%, while for 3D TOF was 94%, 100%, and 98%, and for 3D PC 86%, 98%, and 95%. The comparison of the three different MRA techniques provided no statistically significant difference (Friedman test P<0.05). Conclusion: The high degree of diagnostic accuracy of MRA found in the study of the steno-occlusive disease of the carotid arteries confirms the high degree of reliability of this methodology carried out with the 3D TOF technique, compared to 2D TOF and 3D PC.     

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。     

MR angiography of the pedal arteries with gadobenate dimeglumine, a contrast agent with increased relaxivity, and comparison with selective intraarterial DSA

PURPOSE: To compare gadobenate dimeglumine (Gd-BOPTA)-enhanced MR angiography (i.e., contrast-enhanced MRA [CE-MRA]) of the pedal vasculature with selective digital subtraction angiography (DSA) in patients with peripheral arterial occlusive disease (PAOD). MATERIALS AND METHODS: A total of 22 patients with PAOD were prospectively examined at 1.5T. For contrast enhancement, 0.1 mmol/kg body weight of Gd-BOPTA were applied. MRA consisted of dynamic imaging with acquisition of six consecutive data sets. Acquisition time for each data set was 24 seconds, voxel size was 1.0 x 1.0 x 1.3 mm(3). A total of 20 out of 22 patient underwent selective DSA, two patients fine-needle DSA. DSA and MRA were performed within seven days. Image analysis was independently done by two observers with assessment of overall image quality, motion artifacts, detection of patent vessel segments of the distal calf and pedal vessels, and the number of patent metatarsal arteries. After four weeks, a consensus reading of DSA images was done. A second consensus reading of CE-MRA was performed after a further six weeks. RESULTS: Consensus readings of MRA and DSA revealed higher image quality and fewer motion artifacts for MRA (P = 0.021 and P = 0.008, respectively, sign test); interobserver agreement was good (kappa = 0.78) for image quality, and moderate (kappa = 0.46) for motion artifacts. There were no differences between CE-MRA and DSA in detecting patent vessel segments with a high degree of agreement (kappa = 0.89), and interobserver agreement for MRA was substantial (kappa = 0.89). Significantly more vessels were assessed as partially occluded on DSA than on CE-MRA (P = 0.004). There was a good agreement between DSA and CE-MRA for assessment of relevant vessel stenosis (kappa = 0.61); interobserver agreement for MRA was good (kappa = 0.65). CE-MRA detected significantly more patent metatarsal arteries than did DSA (P < 0.001). CONCLUSION: Gd-BOPTA-enhanced MRA is comparable to DSA for assessment of the pedal vasculature, and is able to delineate significantly more patent vessels without segmental occlusions and more metatarsal arteries than selective DSA.     

门静脉、肝静脉和下腔静脉的三维动态增强MRA:快、慢速灌注法的对比研究

目的：比较快速和慢速注射造影剂法３ＤＤＣＥＭＲＡ显示ＰＶ，ＨＶ和ＩＶＣ的差别；评价３ＤＤＣＥＭＲＡ在门静脉和肝脏静脉系统中的使用价值。材料和方法：本研究分两部分。首先行肝脏横断面动态扫描，测定快速法和慢速法注射造影剂ＰＶ、ＨＶ和ＩＶＣ达信号峰值的时间，以确定第二部份快速法和慢速法３ＤＤＣＥＭＲＡ的最佳延迟时间。然后在此基础上，我们做了４０次快速法和８０次慢速法３ＤＤＣＥＭＲＡ成像。对两种增强方式显示血管的差异进行比较，并对各种病变的３ＤＤＣＥＭＲＡ的表现做分析。结果：快速法和慢速法均能较好显示ＰＶ，显示效果相仿（ｐ＞０．０５）。慢速法显示ＨＶ和ＩＶＣ效果较好，优于快速法（分别为ｐ＜０．０１，ｐ＜０．０５）；３ＤＤＣＥＭＲＡ能较好显示多种疾病。结论：快速法和慢速法３ＤＤＣＥＭＲＡ显示ＰＶ均较满意，但后者显示ＨＶ和ＩＶＣ优于前者，对于门静脉和肝脏静脉系统多种疾病的显示和诊断具有重要价值     

Time-of-Flight MR Angiography of Carotid Artery Stenosis: Does a Flow Void Represent Severe Stenosis?

BACKGROUND AND PURPOSE: Time-of-flight (TOF) magnetic resonance angiography (MRA) is commonly used to visualize the carotid arteries; however, flow void artifacts can appear. Our purpose was to determine the frequency and diagnostic meaning of flow voids by using real patient data, as part of a larger study of MRA compared with the criterion standard, digital subtraction angiography (DSA). METHODS: In 1997-2000, 390 consecutive patients with sonographic findings suggestive of carotid artery stenosis were included in this study. All patients subsequently underwent three-dimensional (3D) TOF MRA and conventional DSA. The frequency of flow void artifacts on 3D TOF MRA images were compared with stenosis measurements on DSA images. RESULTS: We recorded 107 flow voids (16%) during 3D TOF MRA of 662 carotid arteries. DSA images were available for comparison in 102 cases. The median percentage of stenosis in this subgroup of flow voids on MRA images was 80%, compared with measurements on DSA images according to the North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria. Stenoses ranged from 36% to 100% (occlusion). Three flow voids (2.9%) were in the 0-49% range; 11 (10.8%), in the 50-69% range; and 86 (84.3%), in the 70-99% range. Two flow voids (2.0%) represented occlusions. The positive predictive value of a flow void artifact for the presence of severe (70-99%) stenosis was 84.3% (95% CI: 77.3%, 91.4%). CONCLUSION: Flow void artifacts represented severe stenosis in most of the arteries. According to our data, the assumption that flow voids on 3D TOF MRA images represent severe stenosis is justified.