首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
脑肿瘤磁共振血管成像的初步研究   总被引:1,自引:0,他引:1  
目的:应用TOF法MRA显示脑肿瘤的肿瘤血管、供血动脉、引流静脉和脑血管移位与侵犯等,以探讨MRA无创性评价脑肿瘤的价值。材料与方法:对43例脑肿瘤患者进行了TOF法MRA(n=43)与脑血管造影(n=15)和/或手术结果(m=41)对比评价。采用1.0T超导MR系统,二维或三维FISP扫描,用或不用预饱和技术和Gd-DTPA,MIP重建获取MRA图像。结果:MRA准确了76.2%的肿瘤富血管度,  相似文献   

3.
Can non-neuroradiologists detect intracranial aneurysms as well as neuroradiologists, using CT and MR angiography? Sixty patients undergoing intra-arterial digital subtraction angiography (IADSA) to detect aneurysms also underwent computed tomographic angiography (CTA) and time-of-flight magnetic resonance angiography (MRA). Consensus review of IADSA by two neuroradiologists was the reference standard. Two neuroradiologists, a neurosurgeon, a neuroradiographer and a general radiologist blinded to IADSA, plain CT and clinical data, independently reviewed hard-copy base and reconstructed maximum intensity projection images of the CTA and MRA studies. Thirty patients had a total of 63 aneurysms, 71.4% were 相似文献   

4.
旋转DSA的临床应用   总被引:12,自引:2,他引:10  
目的 评价旋转DSA的临床应用价值。方法 采用PHILIPSV5 0 0 0数字成像系统 ,对 3 0例患者实施旋转式数字减影血管造影 48例次。其中脑动脉 8例 ,颈动脉 2例 ,四肢动脉 7例 ,肝动脉 2例 ,肺动脉 1例 ,髂动脉 2例 ,腹主动脉 1例 ,肾动脉 2例以及子宫动脉 5例。结果  3 0例患者 2 8例良好地显示了病变处血管起源、走行、分布、数目、轮廓以及假性动脉瘤的瘘口。结论 旋转式数字减影血管造影能够清楚显示所检查部位的血管结构 ,对病变的术前诊断和制定手术计划具有重要的参考价值。  相似文献   

5.
目的:提供颈动脉狭窄影像与手术、病理对照的初步研究资料,方法:8例颈动脉行DUS、MRA、CTA检查,后行重度狭窄侧颈动脉内膜切除术及影像-病理对照。结果:单侧颈动脉重度狭窄达70%-99%,狭窄侧脑部梗塞灶多于无狭窄侧分布区,狭窄部位与术前DUS、MRA、CTA所示相符,DUS评估狭窄程度相符6例,MRA相符7例,CTA8例。CTA显示为高密度斑块者,DUS回声强,MRA为低信号,病理见钙化灶及纤维组织;CTA为低;等密度者,DUS回声低,MRA信号强度不均,斑块镜下显示无定形坏死物质及积聚脂质的泡沫细胞,结论:DUS、MRA、CTA结合使用能提高诊断颈动脉狭窄的准确性,CTA对斑块的观察更为直观,确切。  相似文献   

6.
On the basis of our first experiences, a purchasable angiography system for peripheral angiography with dynamic subtraction and stepping (DPSA) has been developed. This study reports on the optimization of this technique and the first clinical results in comparison with conventional screen-film angiography and digital subtraction angiography (DSA) in single steps. For each method, 25 angiograms were interpreted to compare the image quality, the radiation exposure, the contrast medium and the film consumption as well as the examination time. Image quality proved to be comparable in DPSA and DSA in single steps. Both techniques showed better results than conventional angiography, especially in the region of the knee and lower leg. Using DPSA radiation exposure dropped by a factor of 2 compared with conventional angiography and by a factor of 6 compared with DSA in single steps. Consumption of contrast medium can also be reduced in comparison with the other two methods. Film consumption is incomparably higher in conventional screen-film angiography. With DPSA the examination time can be reduced by half on average compared with the other two methods. DPSA may come to be the standard in peripheral angiography. Correspondence to: U. Fink  相似文献   

7.
First-pass radionuclide angiography (FPRA) in the 30° right anterior oblique and equilibrium gated radionuclide angiography (EGNA) in the 45° left anterior oblique were used for quantitative measurements of left ventricular ejection fraction (LVEF). Equipment used was a 400T gamma-camera interfaced with a Simis III Informatek computer. The results were compared with contrast angiography (CA). The aim of this study was to determine the sensitivity of both radionuclide techniques. The present data are based on 65 patients in whom CA and EGNA were performed. In 47 patients both FPRA and EGNA were performed. Results suggested that in ischemic heart disease (IHD) and valvular heart disease (VHD) the EGNA technique is well correlated with CA (r=0.9 and 0.73, respectively). FPRA correlated well only with CA in IHD (r=0.86), but not in VHD (r=0.18). This study indicates that both FPRA and EGNA are sensitive, noninvasive techniques for measuring ejection fraction in IHD, while in VHD, EGNA is more sensitive technique than FPRA.  相似文献   

8.
大根髓动脉是脊髓胸腰段的主要供血动脉。脊髓75%的血供来源于大根髓动脉。为防止脊髓缺血性损伤,在对降主动脉胸腹段进行有创性治疗时,需要辨明脊髓血供的解剖特征。应用多排螺旋CT可以通过简单的扫描程序及简捷的后处理成功显示大根髓动脉。合理的对比剂流速及自动阈值触发技术的应用是成功显示的关键。  相似文献   

9.
目的:应用 Meta 分析法,以 DSA 为金标准,探讨 CT 肺动脉成像(CTPA)和磁共振肺血管成像(MRPA)对肺动脉栓塞(PE)的诊断价值。方法:检索 Cochrane 图书馆、Medline 数据库、Springerlink 数据库及 Ovid 循证医学数据库中1994~2013年发表的英文文献以及知网数据库和万方医学数据库中1994~2013年发表的中文文献,按照 Cochrane 协作网推荐的诊断性实验的纳入标准,严格筛选与“CTPA 和/或 MRPA 诊断急性 PE”相关的文献。在符合条件的文献中提取诊断信息(包括真阳性值、假阳性值、真阴性值、假阴性值)和其它相关数据。采用 Stata 12软件和 Meta-disc 1.4软件对纳入文献行统计学处理,包括异质性检验,计算敏感度和特异度及其95%可信区间,选择相应的效应模型予以加权定量合并,绘制汇总的工作特征曲线(SROC),最后进行敏感性分析。结果:按照纳入标准共获取有效文献17篇,其中与 CTPA相关的文献10篇,与 MRPA 相关的文献7篇。17篇文献均满足诊断性研究质量评价工具(QUADAS)中提出的14项标准中的10项以上。CTPA 及 MRPA 两组中的相关研究均有异质性,按照随机效应模型对纳入文献进行汇总分析。结果显示,CTPA 诊断肺栓塞的敏感度、特异度及各自的95%可信区间分别为0.78(0.74~0.82)和0.90(0.87~0.92),MR-PA 为0.86(0.79~0.92)和0.97(0.94~0.99),SROC 下面积分别为94%和98%。结论:CTPA 和 MRPA 对急性肺栓塞的诊断均具有很高的价值,两种方法的诊断特异度均很高,作为诊断肺栓塞的无创性检查方法可基本替代 DSA 检查。  相似文献   

10.
Introduction Cervical artery dissection is an important cause of ischemic stroke, particularly in young patients. The diagnosis can be made with invasive catheter angiography or non-invasive imaging, either with MRI in conjunction with MR angiography (MRA) or CT angiography (CTA). Both modalities have been shown to have a high specificity and sensitivity. New developments such as multi-slice CTA (MSCTA) are emerging as an alternative methods for imaging the cervical and intracranial arteries. However, the contribution of modern MSCTA to carotid artery dissection has not been reported.Methods We present a retrospective series of seven patients in whom both MSCTA and cervical axial T1 MRI and MRA were performed in the acute to subacute setting of internal carotid artery dissection.Results Carotid artery dissection was identified in all seven patients by MSCTA. The combination of MRI and MRA identified dissection in five of the seven patients. Additionally, a pseudoaneurysm was identified by MSCTA that was missed by MRI and MRA.Conclusion Our findings confirm that MSCTA is a complementary technique in comparison to cervical axial T1 MRI and cervical MRA for diagnosing carotid artery dissection, and at times may provide additional information that can impact patient management.  相似文献   

11.

Objective

To evaluate value of adding non-contrast MR angiographic sequence (In-Flow Inversion Recovery [IFIR]) to standard fat-suppressed T1-weighted postcontrast sequence (3D spoiled gradient echo [3D-GRE]) for evaluating hepatic arterial anatomy.

Methods

Retrospective evaluation of 30 consecutive patients undergoing multiphase liver MRI. Individual vessels for IFIR/3D-GRE sequences were evaluated by two blinded readers using a four-point scale. Statistical analysis was performed using the Wilcoxon signed-rank test for vessel conspicuity between IFIR/3D-GRE sequences.

Results

IFIR alone diagnostically imaged 8.1% of vessels, 3D-GRE alone 25.8%, 55.8% by both 3D-GRE/IFIR, and 10.3% of vessels by neither. Two patients with variant vascular anatomy were visualized with both sequences. Addition of IFIR to 3D-GRE resulted in statistically significant increase in arterial visualization (p < 0.001), 10% relative increase in identified vessels, and 3–5 mi increase in acquisition time for total scan time of 30–35 min.

Conclusions

IFIR may be a useful adjunct to 3D-GRE in hepatic angiography without adding considerably to scan time. 10% more hepatic arteries were seen when combining information from IFIR/3D-GRE vs. 3D-GRE alone.  相似文献   

12.
崔喜民  宋忠海  喻骏  孟涛疆 《武警医学》2016,27(12):1214-1217
 目的 比较CT血管造影术(CT angiography,CTA)与磁共振血管造影(magnetic resonance angiography,MRA)诊断动脉瘤与动脉瘤破裂的风险评估价值。方法 48例高度怀疑为颅内动脉瘤患者随机分为两组,每组24例,记为Ⅰ组和Ⅱ组,其中Ⅰ组行CTA+DSA检查,Ⅱ组行MRA+DSA检查。比较CTA及MRA对颅内动脉瘤的诊断灵敏度、诊断特异性、阳性预测值、阴性预测值及准确率。比较CTA及MRA对5 mm以上动脉瘤的诊断价值。结果 MRA诊断颅内动脉瘤的诊断灵敏度、诊断特异性、阳性预测值、阴性预测值、准确率较CTA稍低,但二者差异无统计学意义。CTA与三维增强MR血管成像(3D CE-MRA)对5 mm以上动脉瘤的诊断能力相当,但与三维时间飞跃法MR血管成像(3D TOF MRA)相比,CTA与CE-MRA的诊断灵敏度、诊断特异性、阳性预测值、阴性预测值、准确率明显较高,差异有统计学意义(P<0.05);CTA能更清楚地显示瘤颈。结论 CTA和MRA可作为诊断动脉瘤与动脉瘤破裂的风险评估的首要手段,CTA诊断的准确率及三维形态高于MRA。  相似文献   

13.
Summary Sixty-nine patients with 91 separate abnormal findings were studied by both intra-arterial digital subtraction arteriography (ADSA) and conventional film screen subtraction arteriography (CFSA) in the same projection, with the same magnification. Digital subtraction arteriography has distinct advantages over CFSA in the form of reduced contrast utilization, better patient tolerance of arteriography because of reduced contrast concentration, superior contrast resolution, and rapid, on-line visualization of the abnormalities. Digital subtraction arteriography is limited by its availability in only a single plane, by decreased spatial resolution which affected the image quality for intracranial blood vessels at an image intensifier (I.I.) field of 12 inches, and by relatively limited field of view both intracranially and extracranially for I. I. fields of 6 and 9 inches.  相似文献   

14.
We obtained the venograms using the two-dimensional digital subtraction angiography (2D DSA) images and three dimensional rotation venography (3D RV) images and investigated the potential usefulness of the 3D RV compared with venograms of 2D DSA using the newly developed three-dimensional rotation angiography unit with a flat-panel detector (FPD). This study included 26 sides (11 left, 15 right) in 20 cases (4 males and 16 females) who underwent radiographic examination for management of intracranial tumors and vascular diseases between May 2003 and December 2003. Each patient underwent diagnostic angiography performed on a DSA unit with a FPD. In all patients, the 2D DSA images, including anteroposterior view and lateral view of the carotid artery, were obtained in two stereoscopic views. The 3D RV was used to produce volume-rendered images. Two neuroradiologists investigated the venous configuration of 3D RV compared with that of 2D DSA about the relationship of the venous drainage system on the temporal lobe according to Guppy et al.s classification. Twenty-four sides of the 26 sides enabled the precious visualization on 3D RV images. In investigation of 2D DSA, 9 sides (37.5%) were classified into type A, 13 (54.2%) into type B, two (8.3%) into type C, and no sides into types D, E, and F. In investigation of 3D RV images, 10 sides (41.7%) were classified into type A, 9 (37.5%) into type B, 1 (4.2%) into type C, 2 (8.3%) into type E, and 2 (8.3%) into type F. Seven of 24 sides demonstrated discrepancy in results between 2D DSA and 3D RV. The 3D RV could be performed by setting the adequate delay in between the injection of the contrast material and starting time of third rotation to acquire the opacified images. In Guppy et al.s classification, the 3D RV images could demonstrate the precious venous drainage including the venous lakes with use of multiple views and variable reconstruction compared with 2D DSA. Our DSA system with FPD could provide good 3D RV images. These images are very useful for the skull-base surgery because we can understand the three-dimensional vascular anatomy preoperatively.  相似文献   

15.
The aim of this study was to evaluate imaging features of different coronary artery stents during multislice CT Angiography (MSCTA). Nineteen stents made of varying material (steel, nitinol, tantalum) and of varying stent design were implanted in plastic tubes with an inner diameter of 3 mm to simulate a coronary artery. The tubes were filled with iodinated contrast material diluted to 200 Hounsfield units (HU), closed at both ends and positioned in a plastic container filled with oil (–70 HU). The MSCT scans were obtained perpendicular to the stent axes (detector collimation 4×1 mm, table feed 2 mm/rotation, 300 mAs, 120 kV). Axial images and multiplanar reformations were evaluated regarding artifact size, lumen visibility, and intraluminal attenuation values. Artifacts characterized by artifactual thickening of the stent struts leading to apparent reduction in the lumen diameter and increased intraluminal attenuation values were observed in all cases. The stent lumen was totally obscured in the Wiktor stent, the Wallgraft stent, and the Nir Royal stent. Partial residual of the stent lumen could be visualized in all other utilized stent products (artificial lumen reductions ranged from 62% in the V-Flex stent to 94% in the Bx Velocity stent). Parts of the stent lumen can be visualized in most coronary artery stents; however, detectability of in-stent stenoses remains to be evaluated for each stent type. Electronic Publication  相似文献   

16.
17.
CT和MR血管造影在颅内静脉畸形诊断中的应用   总被引:14,自引:0,他引:14  
目的:评价CT、MR血管造影在诊断颅内静脉畸形中的价值与限度。材料和方法:5例经DSA证实的颅内静脉畸形病例,男2例,女3例,平均年龄37岁(10-66岁),幕上1例,幕下4例。分别在动脉期(CTA)和静脉期(CTV)扫描采样,运用SSD和MIP进行重建,全部病例行MRA、MRV检查,4例做了增强前后MRV检查。结果:CTA显示所有病灶,但没有显示颅内静脉畸形的“海蛇头“,即引流静脉影像特征,而CTV不仅显示病灶,而且还显示了引流静脉“海蛇头“影像特征;MRV显示5例病灶和其特征性的“海蛇头“影像特征,MRA没有一例显示病灶的“海蛇头“表现,4例增强前后MRV没有明显差异。结论:MRV和静脉期的CT血管造影(CTV)是诊断和随访颅内静脉畸形的有效方法,优于动脉期的CT血管造影(CTA),MRA可作筛选之用,排除其他血管性病变。  相似文献   

18.
目的通过与DSA和外科手术对比评价多层螺旋CT血管成像(CTA)对脑动脉瘤诊断的准确性。方法对471例临床怀疑为脑动脉瘤的患者全部行CTA和DSA检查。所有CTA及DSA图像由两位神经放射科医师独立进行分析评价。以DSA和外科手术结果作为参考标准计算多层螺旋CTA诊断脑动脉瘤的准确性。结果多层螺旋CTA诊断所有动脉瘤的敏感性、特异性和准确性分别是97.0%、98.3%和97.6%,阳性和阴性预测率分别是98.5%和96.6%。多层螺旋CTA对于动脉瘤检出的敏感性与DSA的结果差别没有统计学意义(P〉0.05)。结论多层螺旋CTA对于脑动脉瘤检出具有很高的敏感性、特异性和准确性,它在脑动脉瘤的筛选和诊断可以替代常规DSA检查。  相似文献   

19.
目的探讨三维对比增强磁共振血管成像(3D CE-MRA)在颈部动脉血管狭窄诊断中的临床应用价值。方法对23例临床拟诊颈部动脉血管狭窄行数字减影血管造影(DSA)的患者行颈部3D CE-MRA。将两种方法检查结果进行相关性比较。结果 23例患者共230个节段血管,3D CE-MRA显示了227个节段,共诊断出74处(32.6%)狭窄,其中28处轻度狭窄,22处中度狭窄,20处重度狭窄,4处闭塞;DSA共显示了230个节段的血管,共诊断出69处(30.4%)血管狭窄,其中24处轻度狭窄,23处中度狭窄,19处重度狭窄,3处闭塞。与DSA相比,3DCE-MRA对颈部动脉轻度、中度、重度狭窄及动脉闭塞的显示敏感性均为100%,特异性分别为85.71%、90.91%、90%和75%,两种检查方法对颈部动脉狭窄程度的判断有良好的一致性(κ=0.921,P=0.000)。结论 3.0T 3DCE-MRA能够可靠的评价颈部动脉狭窄性病变,基本可以替代DSA检查。  相似文献   

20.
A method for MR angiography after bolus injection of a normal dose (0.1 mmol/kg) of contrast agent is presented. Projection angiograms are acquired with a non-slice selective Snapshot FLASH sequence with a time resolution of 1 s per image or better. Typically 40 to 60 images are acquired consecutively after bolus injection of a contrast agent. The signal from vessels can be separated from background by postprocessing based on the observed temporal evolution of the signal intensities during bolus passage. The subsecond projection MR-DSA is a reliable and robust technique to produce high resolution anatomical images of the vascular system avoiding the necessity of exact timing of the contrast agent bolus. It also supplies functional information about the hemodynamics in the observed region including perfusion.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号