探讨256层螺旋CT血管造影对主肾动脉及肾段动脉的显示

目的：探讨256层螺旋CT血管造影（DSCTA）对主肾动脉及肾段动脉的显示能力及图像质量评价。方法回顾性分析98例256层螺旋C T和94例64层螺旋C T检查的肾动脉M SC T A图像,以C T原始横断位图像为基础,结合V R、M IP等重建图像对各级肾动脉进行综合分析。结果98例患者共显示肾动脉196条,主肾动脉及Ⅰ级、Ⅱ级皆显示清晰,显示率为100％,Ⅲ级分支显示率98．3％,Ⅳ级分支为90．2％,Ⅴ级分支为72．9％,Ⅵ级分支为30．9％。94例患者共显示肾动脉188条,其中主肾动脉及Ⅰ级皆显示清晰,显示率为100％,Ⅱ级分支显示率99．1％,Ⅲ级分支显示率90．3％,Ⅳ级分支为70．2％,Ⅴ级分支为4．8％,Ⅵ级分支为0％,两者比较具有统计学差异（P ＜0．05）。两组图像质量评分分别为（4．537±0．177）分和（3．965±0．189）分,两者比较具有统计学差异（ P ＜0．05）。结论256层螺旋C T血管造影显著提高了肾动脉图像质量,特别是对肾段动脉的显示,从而为临床诊断肾段动脉狭窄和了解肾肿瘤分支血供提供了重要的信息。     

螺旋CT血管造影及血管仿真内镜技术对肾动脉狭窄的诊断与评价

目的：探讨螺旋CT血管造影（SCTA）及血管仿真内镜技术（CTVE）在肾动脉狭窄（RAS）诊断中临床应用价值。方法：7例RAS及1例RAS肾切主后患者行肾动脉SCTA及三维重建，三维重建方法包括：表面遮盖成像（SSD）和最大密度投影（MIP）。3例同时行肾动脉血管CTVE成像。结果：SCTA2DCT图像显示7例RAS患侧肾体积明显缩小，肾皮质明显变薄，无或部分强化。7例RASSSD和MIP均可清晰显示肾动脉主干狭窄的部位、狭窄程度与范围，但不能显示肾段较小肾动脉的狭窄情况。1例RAS肾切除术后MIP和SSD未见肾动脉有其分支显示。3例肾血管CTVE能显示狭窄的肾动脉开口及管腔明显变窄。结论：SCTA及CTVE是诊断肾动脉主干狭窄的有效方法，基本上可代替动脉血管造影。     

64层CT肾血管成像在肾移植供体评价中的临床应用价值

目的:评价64层螺旋CT肾血管成像技术在肾移植供体评价中的临床应用价值。方法:对40例亲属供肾者行64层螺旋CT肾血管成像,应用容积再现(VR)、最大密度投影(MIP)、多平面重组(MPR)等技术进行肾血管重建,评价供肾血管情况,将影像学表现与术中所见进行对照。结果:40例供肾者1次屏气完成扫描,均获得满意的轴面图像,应用VR、MIP、MPR等后处理技术重建肾血管,可清晰显示肾动脉主干及其2～4级分支。9例单侧肾由副肾动脉供血,其中8例单侧肾见单支副肾动脉,1例双侧肾各见1支副肾动脉;9例存在肾动脉分支过早,其中1例双肾动脉均为肾动脉分支过早,共10支血管距离肾动脉开口在1.5cm以内;2例显示肾静脉解剖变异。CT血管成像对供肾动静脉主干、副肾动脉、肾动脉分支过早、肾静脉主干变异的显示与术中所见一致。结论:64层螺旋CT肾血管成像是肾移植术前评价活体供肾血管的一种无创、安全、经济、有效的检查方法。     

多层螺旋CT肾动脉造影的临床应用

目的 评价多层螺旋CT血管造影(MSCTA)在肾动脉病变中的临床应用价值.方法 对90例临床怀疑肾血管疾病患者行肾动脉MSCTA检查,将获得的轴位扫描图像行3D后处理,包括容积再现(VR)、多平面重组(MPR)、最大密度投影(MIP)、曲面重建(CPR).结果 一侧肾动脉狭窄≥50%者43例,≥75%者5例,平均为26.7%;双侧肾动脉狭窄≥50%者13例,≥75%者3例,平均为8.9%;副肾动脉的出现率:1支出现率平均为24%,2支出现率为3.8%;9例出现双侧副肾动脉,出现率为10%.结论 MSCTA可作为怀疑肾血管疾病患者的筛选检查.     

探讨多层螺旋CT组合后处理技术评价肾段动脉的价值

目的探讨MSCT组合后处理技术对肾段动脉成像的显示价值。方法回顾性分析102例行肾动脉造影患者的影像学资料,并分别采用3种不同组合后处理技术评价分析各级肾段及大体解剖图像,A组为:多平面重组(MPR)+最大密度投影(MIP);B组为:MPR+容积再现(VR);C组为:MPR+曲面重组(CPR),并进行统计学分析。结果 102例患者的肾动脉主干Ⅰ级、Ⅱ级肾段动脉分支皆显示清晰,三组之间比较无统计学差异(P0.05),A组对于肾段动脉三级分支及肾动脉大体解剖的显示均高于B组和C组,组间比较具有统计学差异(P0.05)。结论采用MPR+MIP组合后处理技术能很好的显示Ⅲ级以下肾段动脉及其大体解剖,可以为临床诊断肾段动脉狭窄和了解肾肿瘤分支血供提供了重要的信息。     

16层-螺旋CT三维重建对活体供肾的评估价值

目的 探讨16层螺旋CT三维重建在活体供肾血管解剖、肾功能评估中的应用价值.方法 使用飞利浦Brilliance 16层螺旋CT扫描机对37例活体供肾者术前行螺旋CT扫描,采用容积再现技术(VR)、最大密度投影(MIP)、多平面重建(MPR)、曲而重建((2PR)重建方法进行肾血管及肾实质的三维重建技术,使用层块体积测量方法测量肾脏体积并与肾小球滤过率(GFR)进行比较,测量肾动脉直径并与GFR进行比较.结果 螺旋CT三维重建血管造影显示肾脏血管的准确性为89.2%,在各种三维重建方法中,VR在显示肾脏血管全貌、不同角度观察血管方面比较清晰,MPR显示肾脏实质较好.MIP结合轴位图像在判断血管分支,确定血管数量和显示血管有无异常方面比较准确,肾脏体积与GFR呈正相关,肾动脉直径与GFR无明显相关性.结论 螺旋CT三维重建技术在显示血管、肾实质及肾脏功能的评估中有明显作用.     

螺旋CT血管成像与后处理技术对活体供肾血管的评估

 目的评价螺旋CT三维重建技术在亲属活体供肾血管术前评估的价值.方法2004年10月～2005年11月亲属活体供肾移植术6例,术前行螺旋CT血管造影.采集的轴位图像数据传入影像工作站,分别使用VR、MIP和MPR技术进行图像后处理,评估供肾血管状况,并与肾移植取肾手术相对照.结果VR技术后处理显示肾动静脉主干及2～3级分支(6/6),副肾动脉(0/3),肾静脉走行变异(1/1),双侧下腔静脉(1/1);MIP、MPR技术后处理均显示肾动、静脉主干及2～4级分支(6/6),副肾动脉(3/3),肾静脉走行变异(1/1),左肾静脉2支属支(1/1),双下腔静脉(1/1).图像后处理综合结果与取肾术中所见完全一致,敏感性和准确性均为100%.结论MIP及MPR技术观察细小血管分支优于VR.SCTA及图像后处理技术,术前可替代DSA对亲属活体供肾血管作准确评估.     

64层螺旋CT血管成像对下肢动脉系统疾病的应用价值

目的:探讨64层螺旋CT血管成像术在下肢动脉疾病中的应用价值及技术优势。方法:对21例疑有下肢动脉疾病患者行64层螺旋CT增强扫描,扫描范围从肾动脉水平达足底。薄层重建横断面图像传入Wizard工作站,进行血管三维重建。其中21例结合常规血管造影评价64层螺旋CT血管成像术(CTA)的准确性。结果:在441个动脉节段中,435个节段在CTA与DSA均可以显示,在DSA图像上,狭窄闭塞的节段共130个(轻度狭窄16段,中度狭窄12段,重度狭窄22段,闭塞80段),最大密度投影(MIP)显示中度以上狭窄的敏感性、特异性及准确性分别为:99.1%、99.7%、99.5%。结论:64层CT血管成像是一种高度准确、非侵袭性的成像技术,在评估下肢动脉疾病方面与常规血管造影结果无明显差别,是下肢动脉疾病较好的影像学检查手段。     

16层螺旋CT肾脏皮质早期扫描及CTA在肾癌诊断和术前评估中的价值

目的:探讨16层螺旋CT肾脏皮质早期扫描及血管成像在肾癌定性诊断及术前评估中的价值。材料和方法:采用Siemens16层螺旋CT机,对超声提示有肾占位性病变的46例病人进行扫描,利用获得的皮质早期容积数据,显示肾占位性病变对邻近肾内动脉分支的影响、肿瘤血管及类似肿瘤染色等方面的情况,同时显示肾动脉有无变异和其他病变。结果:28例肾癌中23例(82.1%)在皮质早期病灶即呈明显强化,实质期强化程度迅速下降;25例(89.3%)可见邻近动脉分支的受侵改变;21例(75.0%)可见确切的一支或多支粗大的供血动脉,以及瘤体内可见明显的肿瘤血管影或血池影;23例(82.1%)出现类似血管造影的肿瘤染色表现;2例(7.1%)患肾出现静脉早显;3例(10.7%)病人中患肾出现副肾动脉,其中1例为两支;1例(3.6%)病人患侧肾动脉重度狭窄,健侧肾动脉中度狭窄。8例血管平滑肌脂肪瘤中,仅2例(25%)见供血动脉影,其中1例供血动脉增粗,均未见相邻动脉分支破坏、明显肿瘤血管、血池及肿瘤染色改变。10例囊肿,仅表现为相邻肾动脉分支受压移位、拉直变细。结论:应用优化方案扫描进行皮质早期扫描及CTA重建,不仅为肾癌的定性诊断提供了重要的信息,对肾癌的术前评估也具有重要的补充价值。     

16层螺旋CT在下肢动脉闭塞性疾病中的应用价值

目的:探讨16层螺旋CT血管成像术在诊断下肢动脉闭塞性疾病中的应用价值。方法:对42例临床疑为外周动脉闭塞性疾病的患者行下肢动脉16层螺旋CT血管造影(CTA),扫描范围从肾动脉水平达足底。薄层重建横断面图像传入HP xw8000工作站,进行血管三维重建。所有患者于CTA检查前或后2周内行数字减影血管造影(DSA)。以DSA为金标准,评价CTA诊断的准确性。结果:在882个动脉节段中,870个节段在CTA与DSA均可以显示,在DSA图像上,狭窄闭塞的节段共260个(轻度狭窄32段,中度狭窄24段,重度狭窄44段,闭塞160段),最大密度投影(MIP)显示中度以上狭窄的敏感性、特异性及准确性分别为99.1%、99.7%、99.5%。结论:16层螺旋CT在评估下肢动脉闭塞性疾病方面与常规血管造影结果无明显差别,是下肢动脉闭塞性疾病理想的影像学检查手段,可部分替代DSA检查。     

肾动脉狭窄的三维增强磁共振血管成像诊断

目的:评价高分辨力三维增强磁共振血管成像术(3DCEMRA)对肾动脉狭窄的显示准确性。方法:对30例临床诊断或怀疑肾动脉狭窄患者进行高分辨力肾动脉3DCEMRA检查,分析所有患者的肾动脉和副肾动脉显示质量和病变显示情况,并与DSA做对照。结果:3DCEMRA显示了30例患者总共59支肾动脉主干(1例为单支移植肾动脉),显示率为100%。3DCEMRA显示4支副肾动脉,显示率100%。肾动脉段级分支的显示率为49%。所有病例在动脉显示区域内静脉均未显影或显影淡,对诊断不构成影响。DSA共显示59支肾动脉主干和4支副肾动脉(以63支计算),59支主干中2支闭塞,8支重度狭窄,11支中度狭窄,10支轻度狭窄,28支肾动脉主干和4支副肾动脉都正常。3DCEMRA除把2支轻度狭窄估为中度狭窄,1支中度狭窄估为重度狭窄外,其它结果都同DSA一致,故3DCEMRA显示肾动脉主干和副肾动脉狭窄程度超过50%的有血液动力学意义的明显狭窄的敏感性和特异性分别为100%和95%,阳性预测值为91%,阴性预测值为100%。结论:高分辨力肾动脉3DCEMRA能准确检出肾动脉主干和副肾动脉狭窄,并能较好判断其狭窄程度。     

Efficacy of dual-source CT coronary angiography in evaluating coronary stenosis: initial experience

ObjectiveTo retrospectively assess the diagnostic efficacy of dual-source CT angiography (DSCTA) in detecting and grading coronary stenosis.MethodsInstitutional review board approval and informed consent were obtained. One hundred ten patients were performed with both DSCTA and conventional coronary angiography (CCA) without heart rate or rhythm control in 1 week. Regarding CCA as the gold standard, the assessable rate of coronary arteries and diagnostic value of coronary stenosis using DSCTA were analyzed, respectively. The intermodality agreement between DSCTA and CCA in grading coronary stenosis was assessed using κ test. The value of DSCTA in diagnosing >50% coronary stenoses was also assessed.ResultsThe overall assessable rate of DSCTA was 98.6% in detecting coronary arteries; there was no significant difference between assessable rates from different groups of heart rate (χ²=0.45, P > .05). The efficacy of DSCTA was of 97.9% sensitivity, 97.3% specificity, 90.4% positive predictive value, and 99.4% negative predictive value for coronary stenosis; and 94.7% sensitivity, 96.8% specificity, 83.7% positive predictive value, and 99% negative predictive value for >50% stenoses. The intermodality agreement in diagnosing coronary stenosis was satisfactory (k=0.87, u=58.46, P<.01).ConclusionsAs an effective noninvasive diagnostic tool, DSCTA yields a promising accuracy and reliability in assessing coronary stenosis. It may be recommended as a valuable screening tool for coronary artery disease, and a potential challenge to CCA as well.     

Multidetector–row CT angiography of renal artery stenosis in 50 consecutive patients: prospective interobserver comparison with DSA

PURPOSE: The purpose of this study was to establish the diagnostic value of multidetector-row computed tomography (MDCT) angiography compared with digital subtraction angiography (DSA) for detection and quantification of both main and accessory renal artery stenosis in patients with secondary hypertension. MATERIALS AND METHODS: Fifty consecutive patients scheduled for DSA were considered candidates for MDCT angiography. In all patients, MDCT angiography of the abdominal aorta was performed before DSA. For the purpose of interpretation, the arteries were separately interpreted either with DSA or MDCT angiography in order to provide qualitative and quantitative information. For qualitative evaluation, one experienced reader graded the opacification of renal arteries as excellent, good or poor; for quantitative evaluation, MDCT and DSA were independently evaluated for the number of renal arteries and the presence, location and degree of stenosis in random order by three readers. On the basis of consensus readings, calculations of sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) for detection of degree of stenosis were made by using DSA findings as the standard of reference. Interobserver variability was also assessed. RESULTS: With regard to qualitative analysis, arterial enhancement was considered excellent in 39 patients and good in 11. For quantitative analysis, 73 arteries were classified as normal with DSA. Although 72 of these were also classified as normal with CT angiography, one was overestimated by one grade; at DSA, 16 arteries were classified as moderately stenotic; in two arteries, there was an overestimation of one grade. Perfect correlation was achieved for the diagnosis of occlusion. In two patients, all three readers detected multiple severe stenoses on both modalities, with a "string-of-beads" appearance typical of fibromuscular dysplasia. Accessory arteries were correctly identified as such by all three readers on either DSA or MDCT. Levels of sensitivity, specificity and accuracy regarding degree of stenosis were 100%, 98.6% and 96.9%, respectively, with PPV and NPV of 97.6% and 100%, respectively. When we considered significant arterial stenosis (50%-100% luminal narrowing), sensitivity, specificity and accuracy were 100%, 97.3% and 97.8%, respectively, with a PPV and NPV of 98.2% and 97.8%, respectively. For all observers, interobserver agreement was almost perfect (k=0.81-1) for both MDCT and DSA, with a k value between 0.82 and 0.95. CONCLUSIONS: MDCT angiography is very accurate and robust, even for the assessment of renal artery stenosis, and has the potential to become a viable substitute, in most cases, for diagnostic catheter-based DSA.     

Three-dimensional phase-contrast magnetic resonance angiography: a useful clinical adjunct to gadolinium-enhanced three-dimensional renal magnetic resonance angiography?

OBJECTIVE: To assess the value of three-dimensional (3D) phase-contrast (PC) magnetic resonance angiography (MRA) after gadolinium (Gd)-enhanced 3D MRA for renal artery imaging. METHODS: Twenty-one patients with suspected renal artery hypertension were reviewed. All studies included Gd-enhanced 3D MRA and 3D PC MRA. Blinded interpretation of the images was performed for each technique independently and in combination. Conventional X-ray angiography was used for diagnostic correlation when available. RESULTS: Renal artery stenosis was present in 7 (16.3%) of 43 renal arteries, confirmed by X-ray angiography. MRA images demonstrated 100% sensitivity and 74% specificity for Gd-enhanced 3D MRA and 100% sensitivity and 94% specificity for 3D PC MRA. All vessels were diagnosed correctly when both image sets were viewed. CONCLUSION: 3D PC MRA can improve the specificity of renal MRA by decreasing the number of false-positive Gd-enhanced 3D MRA interpretations.     

Non-enhanced MR angiography of renal artery using inflow-sensitive inversion recovery pulse sequence: A prospective comparison with enhanced CT angiography

Purpose

To prospectively evaluate the diagnostic value of non-enhanced inflow-sensitive inversion recovery (IFIR) MR angiography for the detection of renal artery stenosis (RAS), with enhanced CT angiography performed as the reference standard.

Materials and methods

Sixty consecutive patients suspected of RAS underwent both of IFIR MR and enhanced CT angiography. Subjective image quality, renal artery depiction and renal artery grading were all evaluated on artery-by-artery basis. Spearman rank correlation analysis was used to assess agreement between the two techniques. The diagnostic sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for RAS detection at IFIR MR angiography were calculated.

Results

One hundred twenty-six main renal arteries were visualized on enhanced CT and non-enhanced MR angiographic images, respectively. The Spearman rank correlation was 0.773 (P < .001) for renal artery depiction, 0.998 (P < .001) for renal arteries grading and 0.833 (P < .001) for RAS detection between the two modalities. The sensitivity, specificity, PPV and NPV of IFIR MR angiography for RAS detection demonstrated 100%, 99.0%, 92.0% and 100%, respectively.

Conclusion

Non-enhanced IFIR MR angiography had high sensitivity, specificity, PPV and NPV for RAS detection. It could be the first choice of renal artery imaging methods to avoid ionizing irradiation and renal toxicity from contrast media.     

Doppler ultrasound (pre- and post-contrast enhancement) for detection of recurrent stenosis in stented renal arteries: preliminary results

The purpose of the present paper was to assess whether conventional renal Doppler ultrasound and the commonly used parameters of peak systolic velocity and renal aortic ratio may be an appropriate modality for the follow-up of renal artery stents. A total of 19 arteries in 15 patients was examined with both renal Doppler ultrasound and angiography for the presence or absence of recurrent renal artery stenosis. Disease was considered present on angiography if the arterial diameter was more than 60% stenotic. Doppler criteria for stenosis were either a peak systolic velocity of > 180 cm/s or a renal aortic ratio of > 3.0. Echo enhancement with Levovist (Schering, Berlin, Germany) was used if studies were technically unsuccessful or to improve diagnostic confidence. Renal Doppler ultrasound detected 100% of renal artery stenoses. The specificity was 75%, the positive predictive value was 67% and the negative predictive value was 100%. Echo enhancement improved the technical success rate from 89 to 95% and also increased diagnostic confidence in six examinations. The present limited study suggests that similar renal Doppler parameters as used for the study of unstented renal arteries may be applied to the examination of renal arteries with renal stents in situ. It therefore suggests that Doppler ultrasound may provide an adequate non-invasive means of renal artery stent follow-up, particularly when combined with echo-enhancing agents. Further study is warranted to confirm these initial conclusions.     

64层螺旋CT数字减影脑血管成像在烟雾病诊断中的价值

目的 探讨数字减影CT血管成像(DSCTA)在烟雾病诊断中的价值.方法 回顾性分析54例临床及影像资料确诊为烟雾病患者的脑血管CTA资料,分别用减影法及非减影法CTA对原始扫描数据行后处理,运用X~2检验比较两种方法对颈内动脉(ICA)终末段、大脑前动脉(ACA)及大脑中动脉(MCA)起始段狭窄或者闭塞的检出率,以及颅底异常血管网和椎-基底动脉系统代偿性扩张的显示情况等有无差异,同时评价DSCTA重组图像质量.采用t检验比较DSCTA与常规CTA在后处理时间上是否有差异.结果 DSCTA重组图像的质量均能满足颅内血管病变的显示.DSCTA和常规CTA分别显示46例和32例ICA终末段病变,两者间差异有统计学意义(X~2=9.05,P＜0.01).DSCTA分别显示48例ACA起始段病变、52例MCA起始段病变、38例颅底异常血管网和17例椎-基底动脉系统代偿性扩张,常规CTA则分别显示41、47、34和13例,两种方法间差异无统计学意义(P＞0.05).DSCTA和常规CTA后处理平均时间分别为(8.5±2.5)和(14.5±2.0)min,两者间差异有统计学意义(t=13.77,P＜0.01).结论 DSCTA是一种快速、易行和可靠的CTA技术,有利于烟雾病患者ICA终末端病变的检出,为该病提供了一种安全、准确的诊断方法.     

Renal artery stenosis: CT angiography--comparison of real-time volume-rendering and maximum intensity projection algorithms

PURPOSE: To compare results of helical computed tomographic (CT) angiography with real-time interactive volume rendering (VR) to CT angiography with maximum intensity projection (MIP) for the detection of renal artery stenosis. MATERIALS AND METHODS: Twenty-five patients underwent both conventional and CT angiography of the renal arteries. Images were blindly reviewed after rendering with MIP and VR algorithms. MIP images were viewed in conjunction with axial CT images; VR models were evaluated in real time at the workstation without CT images. Findings in 50 main and 11 accessory renal arteries were categorized as normal or by degree of stenosis. RESULTS: All arteries depicted on conventional angiograms were visualized on MIP and VR images. Receiver operating characteristic (ROC) analysis for MIP and VIR images demonstrated excellent discrimination for the diagnosis of stenosis of at least 50% (area under the ROC curve, 0.96-0.99). Although sensitivity was not significantly different for VR and MIP (89% vs 94%, P > .1), specificity was greater with VR (99% vs 87%, P = .008 to .08). Stenosis of at least 50% was overestimated with CT angiography in four accessory renal arteries, but three accessory renal arteries not depicted at conventional angiography were depicted at CT angiography. CONCLUSION: In the evaluation of renal artery stenosis, CT angiography with VR is faster and more accurate than CT angiography with MIP. Accessory arteries not depicted with conventional angiography were depicted with both CT angiographic algorithms.     

螺旋CT肺动脉造影对肺栓塞的诊断

目的：评价螺旋CT及其肺动脉造影诊断肺动脉栓塞（PE）的价值。方法：回顾性分析12例PE患,均行螺旋CT容积扫描,并在工作站进行图像后处理,获得肺动脉多平面重建图像及三维立体图像。结果：对12例196支肺动脉分支进行分析,受累率为46.4%;栓子发生在主肺动脉、左右肺动脉干及叶段肺动脉。多平面重建图像上表现为充盈对比剂血管内有充盈缺损区,或其远侧方无对比剂充填区。肺动脉成像示,主干血管内可见充盈缺损影,或呈截断状影;叶栓塞或段栓塞亦呈突然“截断状”,其远侧方肺动脉分支不显影或呈纤维状。结论：螺旋CT肺动脉造影不仅可以获得轴位图像,而且可以获得立体图像,可多轴向旋转观察PE部位,是诊断叶或段以上PE可靠而直观的检查方法。