三维增强磁共振血管成像和数字减影血管造影在颈部动脉狭窄闭塞性病变中的对比分析

目的 评价三维增强磁共振血管成像(3D-CE-MRA)诊断颈部动脉狭窄闭塞性病变的准确性及应用价值.方法 对43例可疑颈部动脉狭窄或闭塞的患者分别先后进行3D-CE-MRA和数字减影血管造影(DSA)检查,对成像结果进行对比研究.结果 与DSA相比,3D-CE-MRA 对颈部动脉狭窄闭塞性病变诊断的敏感度为83.0%,特异度为94.1%.结论 3D-CE-MRA对颈部动脉狭窄闭塞性病变的显示具有独特的优势,是一种无创、安全、快速、准确性高的检查方法,可以作为首选的检查方法.     

对比增强数字减影乳腺恶性肿瘤MR成像

目的 评估增强减影在乳腺恶性肿瘤MRI中的临床应用价值。资料与方法30例乳腺恶性肿瘤患者进行MR增强扫描，MR对比剂采用Gd．DTPA(0．1mmol／kg体重)，然后用T1WI增强后的图像与增强前的图像进行减影。所有病例都与手术或病理结果进行对照。结果 减影图像比增强后的图像显示更清晰、更直观。减影前不能清楚判断是否有增强和／或难以明确增强区域的大小；减影后，所有病灶均能作出明确的判断。结论 MR数字减影技术是一种简便易行而有效的图像后处理方法，而且省时、可靠和成像质量高。对T1wI高信号病灶的增强与否和增强区域大小的判断很有帮助。对用MRI诊断乳腺恶性肿瘤具有重要价值。     

下肢动脉硬化性闭塞症的DSA

目的：为给外科手术提供更多信息，对１０５例下肢动脉硬化性闭塞症患者作术前经动脉数字减影血管造影（ＩＡＤＳＡ）检查。材料和方法：经皮动脉穿刺插管后，用非离子型造影剂作腹主动脉下段至双胫腓动脉ＤＳＡ。结果：ＤＳＡ表现有：动脉狭窄、闭塞、血管壁溃疡，血管扭曲、延长，侧支形成。本组有８３例（７９．０％）双侧髂、股动脉呈对称性闭塞和／或狭窄。结论：下肢动脉硬化闭塞症好发于老年男性、常双侧发病，股髂动脉最易受累，ＩＡＤＳＡ能满足手术医生术前了解病变的需要，其对患者的创伤较小，可作为术前的常规检查方法     

大脑中动脉狭窄的磁共振血管成像与数字减影血管造影的对照研究

目的 探讨磁共振血管成像(MRA)在大脑中动脉狭窄或闭塞病变中的诊断价值.方法 35例缺血性脑血管病患者先后行MRA及DSA检查,以DSA为金标准,分析MRA对不同程度大脑中动脉狭窄的诊断价值.结果 35例患者70支大脑中动脉中,MRA显示正常血管28支,病变血管42支,病变部位47处,MRA与DSA诊断符合53处,符...     

三维对比增强磁共振血管成像与数字减影血管造影对大动脉炎诊断价值的对照研究

目的与数字减影血管造影(DSA)相比较,评估3DCE-MRA对于大动脉炎(TA)的诊断价值。方法 22例临床怀疑大动脉炎的病人纳入本研究,并按照1990年美国风湿病     

三维磁共振管壁成像与数字减影血管造影诊断颈动脉闭塞的对照研究

目的通过与数字减影血管造影(DSA)比较,评价三维磁共振管壁成像(3D-MR-VWI)技术诊断颈动脉闭塞形态学特征的可行性。资料与方法纳入经超声诊断为颅外段颈动脉闭塞(CAO),并于1周内完成3D-MR-VWI和DSA检查的124例患者。评价3D-MR-VWI与DSA在诊断CAO类型和闭塞发生部位的一致性。结果3D-MR-VWI对于颈动脉完全闭塞及闭塞起始部位的诊断与DSA结果均有较高的一致性(Cohen’s κ=0.85,95%CI 0.71~0.94;Cohen’s κ=0.85,95%CI 0.71~0.97)。3DMR-VWI诊断颈动脉完全闭塞的敏感度为97.0%,特异度为86.7%,准确率为94.6%。结论3D-MR-VWI能够准确诊断CAO并判定闭塞的形态学特征,可为临床诊治颈动脉闭塞性病变提供参考。     

数字减影血管造影临床应用的初步体会

本文介绍了51例数字减影血管造影的应用情况。介绍静脉法及动脉法数字减影血管造影方法,并提出静脉法数字减影血管造影创伤小、检查快速、适合于老年及幼年患者,动脉法数字减影血管造影则使图像质量明显提高,优于普通血管造影,并可同时进行介入性治疗。对于可能出现的并发症本文亦一一作了介绍。     

ECG-Triggered Non-Contrast-Enhanced MR Angiography (TRANCE) versus Digital Subtraction Angiography (DSA) in patients with peripheral arterial occlusive disease of the lower extremities

Objective

To prospectively determine the diagnostic value of electrocardiography-triggered non-contrast-enhanced magnetic resonance angiography (TRANCE) of the lower extremities including the feet versus DSA.

Methods

All 43 patients with symptomatic peripheral arterial occlusive disease (PAOD) underwent TRANCE before DSA. Quality of MRA vessel depiction was rated by two independent radiologists on a 3-point scale. Arterial segments were graded for stenoses using a 4-point scale (grade 1: no stenosis; grade 2: moderate stenosis; grade 3: severe stenosis; grade 4: occlusion). Findings were compared with those of DSA.

Results

In the 731 vessel segments analysed, intra-arterial DSA revealed 283 stenoses: 33.6% moderate, 16.6% severe and 49.8% occlusions. TRANCE yielded a mean sensitivity, specificity, positive and negative predictive value and diagnostic accuracy to detect severe stenoses or occlusions of 95.6%, 97.4%, 87.2%, 99.2%, 97.1% for the thigh segments and 95.2%, 87.5%, 83.2%, 96.6%, 90.5% for the calf segments. Excellent overall image quality was observed for TRANCE in 91.4% versus 95.7% (DSA) for the thigh and in 60.7% versus 91.0% for the calves, while diagnostic quality of the pedal arteries was rated as insufficient.

Conclusion

TRANCE achieves high diagnostic accuracy in the thigh and calf regions, whereas the pedal arteries showed limited quality.     

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。     

Intraarterial MR angiography and DSA in patients with peripheral arterial occlusive disease: prospective comparison

PURPOSE: To prospectively evaluate the accuracy of intraarterial magnetic resonance (MR) angiography in the depiction of significant stenoses and occlusions, with intraarterial digital subtraction angiography (DSA) serving as the reference standard. MATERIALS AND METHODS: Approval of the local ethics committee and informed consent were obtained. Twenty patients (11 men; nine women; age range, 48-86 years; mean age, 69.5 years+/-11.2 [standard deviation]) with symptomatic peripheral arterial occlusive disease (PAOD) were prospectively enrolled. After percutaneous transluminal angioplasty (PTA), intraarterial MR angiography was performed in the thigh and the calf with a 1.5-T MR imager in two consecutive runs. Intraarterial MR angiography was performed with a low-dose injection protocol (ie, two 20-mL injections of a 50-mmol gadolinium-based contrast agent). Moderate stenoses (luminal narrowing50%) or vessel occlusions; 95% confidence intervals (CIs) were calculated for sensitivity and specificity. RESULTS: Intraarterial DSA revealed 78 moderate stenoses, 57 significant stenoses, and 28 occlusions. Sensitivity, specificity, and accuracy of intraarterial MR angiography in the characterization of significant stenoses or occlusions were 92% (95% CI: 72%, 99%), 94% (95% CI: 82%, 98%), and 93%, respectively, in femoropopliteal arteries and 93% (95% CI: 83%, 98%), 71% (95% CI: 51%, 86%), and 86%, respectively, in infrapopliteal arteries. The main artifact observed with intraarterial MR angiography was venous contamination (12%). CONCLUSION: Intraarterial MR angiography is an accurate method used to depict significant stenoses and occlusions in lower extremity arteries with a low-dose injection protocol.     

Diabetes and peripheral arterial occlusive disease: prospective comparison of contrast-enhanced three-dimensional MR angiography with conventional digital subtraction angiography

OBJECTIVE: The purpose of this study was to compare contrast-enhanced three-dimensional MR angiography with conventional digital subtraction angiography (DSA) for identifying and evaluating arteries of the distal calf and foot in diabetic patients with severe arterial occlusive disease who will undergo distal bypass surgery. SUBJECTS AND METHODS: Twenty-four feet of 24 consecutive patients with diabetes and limb-threatening lower extremity ischemia were prospectively imaged using an ultrafast three-dimensional fast low-angle shot sequence on a 1.5-T MR scanner. All patients also underwent DSA of the diseased extremity within 5 days. Images were interpreted in a randomized manner by two observers in conference. Each lower extremity was divided into seven potential arterial segments. Image analysis included the detection of patent, stenosed, or occluded vessel segments. A vascular surgeon formulated treatment plans on the basis of findings from DSA and then formulated treatment plans on the basis of findings from both DSA and MR angiography. RESULTS: MR angiography was significantly better than DSA in revealing peripheral runoff vessels (p < 0.001). In nine (38%) of the 24 patients, MR angiography showed patent pedal vessels suitable for distal bypass grafting that were not revealed by DSA. Because of the results of MR angiography, treatment plans changed in seven of the nine patients in whom patent vessels were subsequently used as target vessels for distal pedal bypass grafts. CONCLUSION: Contrast-enhanced three-dimensional MR angiography is superior to DSA in revealing patent vessel segments of the foot in diabetic patients with severe arterial occlusive disease. Contrast-enhanced three-dimensional MR angiography should be part of the diagnostic algorithm for patients in whom pedal bypass grafting is a therapeutic option.     

MR angiography versus intra-arterial digital subtraction angiography of the lower extremities: activity-based cost analysis

PURPOSE: The aim of this study was to analyse the costs pertaining to the radiology department of magnetic resonance angiography (MRA) and intra-arterial digital subtraction angiography (DSA) in the evaluation of arterial disease of the lower limbs. MATERIALS AND METHODS: The differential cost of the two procedures, i.e. the sum of equipment costs (amortisation and service contract), variable costs (supplies and related services) and personnel costs (radiologist, radiographer and nurse) was determined. The common cost (auxiliary personnel and indirect internal costs) was also calculated. Finally, the full cost of the two procedures was obtained (sum of differential and common costs). RESULTS: The differential cost of MRA was 186.14 euro (equipment costs: 50.80 euro, variable costs: 75.04 euro, personnel costs: 60.30 euro) while the differential cost of intra-arterial DSA was 238.18 euro (equipment costs: 57.60 euro, variable costs: 90.13 euro, staff costs: 90.45 euro). The estimated common cost was 5.62 euro. Therefore, the full cost of MRA was 191.76 euro and the full cost of intra-arterial DSA was 243.80 euro (27.1% higher). DISCUSSION AND CONCLUSIONS: Intra-arterial DSA costs more than MRA, mainly because of the higher costs of supplies used during the procedure and higher personnel costs (as a result of the longer duration of intra-arterial DSA). It should be noted that our evaluation considers costs pertaining to the radiology department only. It is evident that an economic analysis considering hospital costs as well would result in much higher costs for DSA if post-procedure hospitalisation is required. Our results cannot be simply exported to other radiology departments since they refer to the technology and organisation adopted in our department. However, our cost analysis model can be easily applied to other environments. MRA provides good diagnostic accuracy in the evaluation of arteries of the lower extremities, and its biological cost is far lower than that of intra-arterial DSA (MRA is noninvasive, it does not use ionising radiation, and the contrast medium is safe). Its lower cost is another argument in favour of the use of MRA instead of intra-arterial DSA in the evaluation of lower-extremity arterial disease.     

Peripheral vascular occlusive disease: evaluation with contrast-enhanced moving-bed MR angiography versus digital subtraction angiography in 106 patients

OBJECTIVE: The purpose of our study was to compare contrast-enhanced moving-bed MR angiography and digital subtraction angiography in the evaluation of peripheral vascular occlusive disease. MATERIALS AND METHODS: This retrospective report includes 106 patients (45 women, 61 men) with known or suspected peripheral vascular occlusive disease who underwent MR angiography and intraarterial digital subtraction angiography of the peripheral arteries. MR angiography was performed on a 1.0-T unit using a moving-bed technique. Every leg was divided into 14 vascular segments, and severity of disease was scored in four categories. Digital subtraction angiography was the standard of reference. RESULTS: In the 106 patients, 2378 vessel segments were evaluated with both imaging modalities. In 2156 segments, MR angiography and digital subtraction angiography were concordant for stenosis classification, in 188 segments the two modalities differed in one category, and in 24 segments they differed in two categories. MR angiography achieved sensitivity and specificity of 96.7% and 95.8%, respectively, for differentiating nonsignificant from hemodynamically significant stenosis (kappa = 0.91). CONCLUSION: This study indicates that MR angiography is an accurate imaging modality in clinical practice. Our data support the concept that MR angiography can modify the diagnosis of suspected peripheral vascular occlusive disease.     

Prospective evaluation of peripheral arterial occlusive disease by 2D MR subtraction angiography

The purpose of this study was to assess the diagnostic value of two-dimensional (2D) MR subtraction angiography of lower extremities in patients with symptomatic peripheral arterial occlusive disease with conventional angiography as the standard of reference. Twenty patients were prospectively included. 2D subtraction MR angiography (MRA) consisted of multisection gradient-recalled echo (GRE) acquisitions with the shortest TE available on our machine (4 msec), obtained in the coronal plane before and after intravenous bolus administration of gadolinium chelate. MR images were reconstructed after subtraction with a maximum-pixel-intensity-projection (MIP) algorithm. MRA was performed in all cases 1–4 days before diagnostic angiography. In a prospective blinded analysis, the number and location of significant (ie, >50%) stenoses and occlusions were evaluated for each vascular segment. Sensitivity and specificity were used to evaluate MRA data. Significant stenoses (38 of 46, 83%) and occlusions (66 of 67, 99%) seen at conventional angiography were identified with MRA. The sensitivity and specificity of MRA for determination of stenoses >50% or occlusions was 100% and 97%, respectively. The location and extent of stenoses and/or occlusions on MRA and angiograms were well correlated (kappa values, r = .73, P < .05). Contrast 2D MR subtraction angiography, by providing comparable information to that of conventional angiography, is well suited to evaluate the presence and severity of atherosclerotic lesions of the lower limbs.     

Whole-body 3D MR angiography of patients with peripheral arterial occlusive disease

OBJECTIVE: We assessed the diagnostic performance of whole-body 3D contrast-enhanced MR angiography in comparison with digital subtraction angiography (DSA) of the lower extremities in patients with peripheral arterial occlusive disease. SUBJECTS AND METHODS. Fifty-one patients with clinically documented peripheral arterial occlusive disease referred for DSA of the lower extremity arterial system underwent whole-body MR angiography on a 1.5-T MR scanner. Paramagnetic gadobutrol was administered and five contiguous stations were acquired with 3D T1-weighted gradient-echo sequences in a total scanning time of 72 sec. DSA was available as a reference standard for the peripheral vasculature in all patients. Separate blinded data analyses were performed by two radiologists. Additional vascular disease detected by whole-body MR angiography was subsequently assessed on sonography, dedicated MR angiography, or both. RESULTS: All whole-body MR angiography examinations were feasible and well tolerated. AngioSURF-based whole-body MR angiography had overall sensitivities of 92.3% and 93.1% (both 95% confidence intervals [CIs], 78-100%) with specificities of 89.2% and 87.6% (both CIs, 84-98%) and excellent interobserver agreement (kappa = 0.82) for the detection of high-grade stenoses. Additional vascular disease was detected in 12 patients (23%). CONCLUSION: Whole-body MR angiography permits a rapid, noninvasive, and accurate evaluation of the lower peripheral arterial system in patients with peripheral arterial occlusive disease, and it may allow identification of additional relevant vascular disease that was previously undetected.     

Imaging of aortoiliac arterial disease. Duplex ultrasound and MR angiography versus digital subtraction angiography

Purpose: To evaluate and compare the diagnostic accuracy of duplex ultrasound (US) and MR angiography (MRA) at 1.0 T in aortoiliac arterial disease using digital subtraction angiography (DSA) as the reference standard. In addition, a comparison of the 2D time-of flight (TOF) and 3D contrast-enhanced MRA (CE MRA) techniques was performed.Material and Methods: Prospectively, 39 patients with symptoms of lower-extremity arterial occlusive disease were examined using US, TOF MRA, CE MRA and DSA. Significant lesions (stenosis ≥50%) and occlusions were evaluated blindly for each method.Results: For all segments, the sensitivity for US, TOF MRA and CE MRA with regard to significant lesions was 0.72, 0.81 and 0.81, respectively, and the specificity for each was 0.97, 0.91 and 0.92, respectively. For significant lesions above the inguinal ligament the corresponding sensitivity was 0.84, 0.89 and 0.94 and the specificity 0.93, 0.82 and 0.73, respectively. The specificity was higher when the two MRA methods were combined. TOF MRA overgraded 7 segments as occluded. In most cases, the length of the occlusions was correctly determined on CE MRA, overestimated on TOF MRA and uncertain on US.Conclusion: Neither US nor MRA were sufficiently accurate to fully replace angiography. MRA was preferable to US as a non-invasive test when vascular intervention was contemplated. Although CE MRA was superior to TOF MRA, the most accurate results were achieved when the two methods were combined.     

Diagnostic performance of computed tomography digital subtraction angiography of the lower extremities during haemodialysis in patients with suspected peripheral artery disease

IntroductionWith intra-arterial digital subtraction angiography (DSA) considered as the gold standard, we compared the diagnostic value of computed tomography angiography (CTA) and computed tomography-digital subtraction angiography (CT-DSA in hemodialysis (HD) patients suspected of having lower limb peripheral artery disease (PAD).MethodsIn this retrospective study, we enrolled 220 HD patients with suspected PAD. CT-DSA images were obtained by subtracting unenhanced images from enhanced images. The research team calculated the area under the curve (AUC), sensitivity, specificity, positive and negative predictive value (PPV, NPV), and recorded the diagnostic accuracy between the CTA and CT-DSA images using the DSA as gold standard. Visual evaluation of calcifications in the peripheral arteries were also compared between CTA and CT-DSA images.ResultsAt the above-knee level, the CTA AUC [95% confidence interval (CI)] was 0.68 (CI 0.64–0.72), sensitivity and specificity were 60 and 81%, PPV and NPV were 85 and 53%, and accuracy was 67%. Below the knee, these values were 0.66 (CI 0.62–0.70), 71 and 79%, 79 and 47%, and 66%. For CT-DSA, above-knee, the AUC [95% CI] was 0.88 (CI 0.85–0.91), sensitivity and specificity were 84 and 92%, PPV and NPV were 89 and 97%, and accuracy was 93%. Below the knee, these values were 0.95 (CI 0.93–0.97), 95 and 93%, 96 and 83%, and 93%. The scores for the visualization of calcification in the peripheral arteries was significantly higher for CT-DSA than CTA (p < 0.05).ConclusionsCT-DSA helps to assess stenotic PAD with high calcification in the lower extremities of HD patients.Implications for practiceOn CT-DSA images, the severity of vascular calcification can be assessed for HD patients suspected of PAD of the lower extremities.