Helical CT angiography in the preoperative evaluation of carotid artery stenosis

Purpose: To determine the utility and accuracy of helical CT angiography (CTA) in the evaluation of carotid artery stenosis. Methods: A comparison of CTA and conventional arteriogram was performed in 53 patients undergoing evaluation for carotid artery stenosis. Ninety-six carotid systems were evaluable. CTA stenosis was determined by the percent of area reduction seen on axial images through the level of greatest narrowing. MIP images were used to identify the point of maximal stenosis and to visualize overall vascular anatomy. The percent diameter stenosis was measured on conventional arteriograms using strict North American Symptomatic Carotid Endarterectomy Trial (NASCET) and European Carotid Surgery Trial (ECST) criteria. Results: Significant correlation was found between CTA and arteriography (NASCET method R = 0.87, ECST method R = 0.87, p < 0.001). Using NASCET >60% as an indicator for disease, CTA had a sensitivity of 87%, specificity of 90%, accuracy of 89%, negative predictive value of 88%, and positive predictive value of 89%. CTA identified plaque characteristics such as ulcerations (8), occlusion (10), fatty plaques (22), calcifications (48), and fibrosis (2). CTA underestimated 2 cases of short segment stenoses because of volume averaging, but this discrepancy was detected by duplex scan. No complications or renal dysfunction occurred with CTA; 1 patient became symptomatic during arteriography, necessitating termination of the procedure. Conclusion: CTA is a safe, non-invasive technique that precisely measures carotid artery area reduction and highly correlates to conventional arteriography. With this new technology, the current standards for carotid artery imaging may need to be reevaluated, and the precise role for helical CTA more clearly defined. (J Vasc Surg 1998;28:290-300.)     

Comparison of intra-arterial digital subtraction angiography, magnetic resonance angiography and duplex ultrasonography for measuring carotid artery stenosis

BACKGROUND: Duplex ultrasonography and magnetic resonance angiography (MRA) are becoming competitive alternatives to angiography for determining the degree of internal carotid artery (ICA) stenosis. Varying reports have been published regarding the suitability of each technique for grading ICA disease. This retrospective study compared the merits of these three modalities for measuring ICA stenosis. METHODS: One hundred and eleven patients being considered for carotid endarterectomy underwent intra-arterial digital subtraction angiography (DSA) via arch injection. Duplex imaging was performed in all patients and MRA in 50. The degree of carotid stenosis estimated by the three modalities was compared. RESULTS: There was good correlation between subjectively graded MRA and DSA images (r = 0.87, P < 0.001, n = 82 carotids) but poor correlation for objective estimates. MRA tended to underestimate the degree of stenosis (bias - 4.5 per cent) compared with DSA, but showed good correlation with duplex ultrasonography estimates (r = 0. 86, P < 0.001, n = 87 carotids). Both non-invasive modalities produced high values of sensitivity and specificity in estimating stenoses of greater than 70 per cent. MRA was less sensitive for distinguishing between severe stenosis and complete occlusion. CONCLUSION: This study did not resolve the debate regarding the method of choice as both MRA and duplex ultrasonography were accurate for imaging carotid stenoses.     

Prospective evaluation of new duplex criteria to identify 70% internal carotid artery stenosis

Purpose: Large multicenter trials (North American Symptomatic Carotid Endarterectomy Trial, European Carotid Surgery Trial) have documented the benefits of carotid endarterectomy for treating symptomatic patients with ≥70% stenosis of the internal carotid artery. Although color-flow duplex scanning has become the preferred method for noninvasive assessment of internal carotid artery disease, no criteria have been generally accepted to identify this subset of patients. We previously reported a retrospective series to establish such criteria. This study details our results when these criteria were applied prospectively.Methods: Carotid color-flow duplex scans were compared with arteriograms in 457 patients who underwent both studies. Criteria for ≥70% internal carotid artery stenosis were peak systolic velocity >130 cm/sec and end-diastolic velocity >100 cm/sec. Internal carotid arteries with peak systolic velocity <40 cm/sec in which only a trickle of flow could be detected were classified as preocclusive lesions (95% to 99% stenosis). Arteriographic stenosis was determined by comparing the diameter of the internal carotid artery at the site of maximal stenosis to the diameter of the normal distal internal carotid artery.Results: Internal carotid artery stenosis of ≥70% was detected with a sensitivity of 87%, specificity of 97%, positive predictive value of 89%, negative predictive value of 96%, and overall accuracy of 95%. Eighty-seven percent of 70% to 99% stenoses were correctly identified. False-positive errors (n = 10) were attributed to contralateral internal carotid artery occlusion or high-grade (>90%) stenosis (n = 5) and to interpreter error (n = 1); no explanation was apparent in the other four. Eleven of 12 false-negative examinations occurred in patients with 70% to 80% internal carotid artery stenosis.Conclusions: In our laboratories, prospective application of the above velocity criteria identified internal carotid artery stenosis of ≥70% with a reasonably high degree of accuracy. Errors occurred when stenoses were borderline and in patients with severe contralateral disease. With suitably modified velocity criteria, color-flow duplex scanning remains the most reliable noninvasive method for identifying symptomatic patients who are candidates for carotid endarterectomy. (J V ASC S URG 1996;23:254-62.)     

Colour duplex scanning versus angiography: a retrospective assessment of carotid stenosis

A retrospective study was performed to investigate the reliability of colour duplex scanning as a screening method in detecting carotid artery disease. The results of this technique and digital subtraction arteriography of 100 carotid bifurcations in 50 patients undergoing carotid endarterectomy were compared. In accordance with suggested standard reports dealing with cerebrovascular disease, the diameter reduction was classified in one of five categories: < 20%. 20–59%, 60–79%, 80–99% and total occlusion. In 78% the gradings determined using digital subtraction arteriography and duplex scanning correlated perfectly, and in 99% of the studied bifurcations the difference was not more than one grade. The sensitivity and specificity of colour duplex scanning in detecting a stenosis with a diameter reduction of more than 60% was 98% and 87.7%, respectively. The best non-invasive method to identify carotid bifurcation disease is duplex scanning. Although the role of duplex scanning as an alternative to angiography is currently evolving, the authors still advocate carotid angiography when surgery is considered.     

Computed tomographic evaluation of extracranial carotid artery disease

Axial computed tomographic (CT) scans after intravenous contrast infusion were used to image the cervical carotid arteries of patients with cerebral ischemic symptoms. Standard transfemoral cervical carotid and cerebral angiography was the principal diagnostic modality used in all patients studied. The angiographic results were compared to the CT images and to the gross and microscopic endarterectomy pathological specimens, when available. Examples of the various types of abnormalities that can be visualized using CT scans are presented. The CT scan was useful for determining the presence of degenerative atheromatous changes including carotid artery calcification, subintimal hemorrhage, carotid occlusion, carotid segmental occlusion, and carotid pseudoocclusion, as well as carotid artery dissection. The scans were particularly useful for identification of atheromatous carotid artery disease when the carotid angiogram appeared nearly normal and for identifying the cause of postoperative carotid stenosis. CT scanning allows visualization of the carotid artery wall and lumen rather than just the lumen and, consequently, can sometimes add helpful information about the pathological processes affecting this artery.     

Variability in measurement of internal carotid artery stenosis by arch angiography and duplex ultrasonography--time for a reappraisal?

OBJECTIVES: to determine the inter- and intra-observer variability of ICA stenosis measurement using duplex, ECST and NASCET methods. DESIGN: a retrospective review of arch angiograms and carotid duplex scans in 50 patients. MATERIALS AND METHODS: carotid stenoses were calculated by three independent observers according to NASCET and ECST methods. Variation between observers for NASCET and ECST was determined. For each observer, the variation between NASCET and ECST was determined. The variation between duplex and both NASCET and ECST was determined. RESULTS: inter-observer agreement on the degree of ICA stenosis was clinically and statistically good for NASCET but was poorer for ECST. For each observer, comparison between NASCET and ECST showed 95% limits of agreement of around 50 percentage points. Comparison of duplex with NASCET and ECST showed similar 95% limits of agreement. CONCLUSIONS: arch angiography allows reproducible measurement of carotid stenosis by the NASCET method between different observers. For the ECST method, reproducibility is not so good. Variations in results between NASCET and ECST and between angiography and duplex are significant. In view of the similar results of the NASCET and ECST trials, this suggests that degree of stenosis may only be a surrogate marker for outcome following carotid endarterectomy.     

Comparison of duplex Doppler scanning with contrast angiography in carotid artery disease

The results of ultrasonic pulsed Doppler duplex scanning with spectral analysis were compared with the results of contrast arteriography in 37 patients screened for extracranial carotid artery disease. The kappa value for this comparison was 0.476 +/- 0.149. The overall diagnostic accuracy of duplex scanning was 91% (67/74 vessels) for agreement within one category of true assessment of stenosis. All 5 occluded internal carotid arteries were identified correctly by duplex scanning. Duplex scanning of the internal carotid artery is one of the few noninvasive tests that has the capability of discriminating normal arteries from minimal disease, minimal disease from severe disease, and severe disease from occlusion. Duplex scanning should be used as the initial test in patients with non-hemispheric symptoms and complete stroke. The intra-operative and postoperative routine assessment of the endarterectomised segment has become mandatory. Duplex scanning is invaluable in the management of the patient with an asymptomatic carotid bruit.     

Renal artery stenosis: evaluation with colour duplex ultrasonography

Background: Detection of renal artery stenoses (RAS) by means of duplex Doppler ultrasound with direct scanning of the main renal arteries is subject to numerous limitations. Using semiquantitative analysis of the Doppler curve, which can be recorded from intrarenal arteries, it is possible to detect RAs unaffected by the problems of direct Doppler scanning of the renal arteries. Method: Both angiography of the renal arteries and colour duplex ultrasonography (US) of the intrarenal vessels (interlobar arteries) were performed in 214 patients (53.2±15.1 years) with severe arterial hypertension. Angiography was used as 'gold standard' in the diagnosis of RAS and the Doppler results were compared with the subsequent findings on angiography. At angiography, the reduction of diameter >70% was assessed as haemodynamically effective RAS. For the duplex Doppler diagnosis of RAS the following parameters were calculated: (a) resistive index (RI) of each kidney, and (b) side-to-side differences of the resistive indices (&Dgr;RI) between the right and left kidney. Results: Angiography demonstrated 59 RAS (>70%) in 53 patients, including six with bilateral RAS. By means of duplex US we found a significant difference of RI between kidneys with RAS (0.48±0.11) and without RAS (0.63±0.08; P<0.001). In addition, a significant difference of the &Dgr;RI was noted in patients with RAS (24.4%±12.5%) and the controls without RAS (3.6%±2.7%). Using a combination of both RI and &Dgr;RI, threshold values of RI=0.45 resp. &Dgr;RI=8% yields a sensitivity of 92.5% and a specificity of 95.7% in the detection of haemodynamically effective RAS. Conclusion: Colour duplex US with calculation of the RI and &Dgr;RI of intrarenal arteries is a valuable non-invasive test assessing the haemodynamic effects of RAS. Low costs and safety support the use of the Doppler technique in screening for renovascular disease.     

Effect of contralateral disease on duplex measurements of internal carotid artery stenosis

BACKGROUND: Duplex ultrasonography is increasingly used as the sole method of imaging before carotid endarterectomy. This study investigated the measured degree of stenosis in the contralateral carotid artery before and after operation. METHODS: Duplex-derived peak systolic velocity (PSV), end-diastolic velocity (EDV) and internal carotid artery/common carotid artery (ICA/CCA) velocity ratios were measured in the contralateral unoperated ICA before 131 consecutive unilateral endarterectomies and compared with preoperative angiographic findings. Three months later duplex scans were repeated to assess whether there had been any alteration in the severity of the stenosis in the contralateral unoperated artery. RESULTS: Bilateral ICA disease (greater than 50 per cent stenosis) was present in 50 patients (38 per cent). Three months after operation, ultrasonography of the 105 unoperated, patent, contralateral arteries showed a decrease in mean(s.d.) PSV (1.21(0. 83) versus 1.07(0.69) m/s; P < 0.01) and EDV (0.41(0.29) versus 0. 35(0.24) m/s; P < 0.01). This resulted in 14 (42 per cent) of 33 patients with contralateral disease being downgraded to a less severe category of stenosis. Use of the ICA/CCA velocity ratio prevented overestimation in eight of the 14 patients, while preoperative angiography correctly classified 13 of the 14 patients. CONCLUSION: Bilateral carotid artery disease can cause overestimation of the severity of stenosis by duplex ultrasonography if absolute velocity is used as the main criterion.     

Reappraisal of velocity criteria for carotid bulb/internal carotid artery stenosis utilizing high-resolution B-mode ultrasound validated with computed tomography angiography

OBJECTIVE: Reliability of the most commonly used duplex ultrasound (DUS) velocity thresholds for internal carotid artery (ICA) stenosis has been questioned since these thresholds were developed using less precise methods to grade stenosis severity based on angiography. In this study, maximum percent diameter carotid bulb ICA stenosis (European Carotid Surgery Trial [ECST] method) was objectively measured using high resolution B-mode DUS validated with computed tomography angiography (CTA) and used to determine optimum velocity thresholds for > or =50% and > or =80% bulb internal carotid artery stenosis (ICA). METHODS: B-mode DUS and CTA images of 74 bulb ICA stenoses were compared to validate accuracy of the DUS measurements. In 337 mild, moderate, and severe bulb ICA stenoses (n = 232 patients), the minimal residual lumen and the maximum outer bulb/proximal ICA diameter were determined on longitudinal and transverse images. This in contrast to the North American Symptomatic Carotid Endarterectomy Trial (NASCET) method using normal distal ICA lumen diameter as the denominator. Severe calcified carotid segments and patients with contralateral occlusion were excluded. In each study, the highest peak systolic (PSV) and end-diastolic (EDV) velocities as well as ICA/common carotid artery (CCA) ratio were recorded. Using receiver operating characteristic (ROC) analysis, the optimum threshold for each hemodynamic parameter was determined to predict > or =50% (n = 281) and > or =80% (n = 62) bulb ICA stenosis. RESULTS: Patients mean age was 74 +/- 8 years; 49% females. Clinical risk factors for atherosclerosis included coronary artery disease (40%), diabetes mellitus (32%), hypertension (70%), smoking (34%), and hypercholesterolemia (49%). Thirty-three percent of carotid lesions (n = 110) presented with ischemic cerebrovascular symptoms and 67% (n = 227) were asymptomatic. There was an excellent agreement between B-mode DUS and CTA (r = 0.9, P = .002). The inter/intraobserver agreement (kappa) for B-mode imaging measurements were 0.8 and 0.9, respectively, and for CTA measurements 0.8 and 0.9, respectively. When both PSV of > or =155 cm/s and ICA/CCA ratio of > or =2 were combined for the detection of > or =50% bulb ICA stenosis, a positive predictive value (PPV) of 97% and an accuracy of 82% were obtained. For a > or =80% bulb ICA stenosis, an EDV of > or =140 cm/s, a PSV of > or =370 cm/s and an ICA/CCA ratio of > or =6 had acceptable probability values. CONCLUSION: Compared with established velocity thresholds commonly applied in practice, a substantially higher PSV (155 vs 125 cm/s) was more accurate for detecting > or =50% bulb/ICA stenosis. In combination, a PSV of > or =155 cm/s and an ICA/CCA ratio of > or =2 have excellent predictive value for this stenosis category. For > or =80% bulb ICA stenosis (NASCET 60% stenosis), an EDV of 140 cm/s, a PSV of > or =370 cm/s, and an ICA/CCA ratio of > or =6 are equally reliable and do not indicate any major change from the established criteria. Current DUS > or =50% bulb ICA stenosis criteria appear to overestimate carotid bifurcation disease and may predispose patients with asymptomatic carotid disease to untoward costly diagnostic imaging and intervention.     

False-negative magnetic resonance angiography with extracranial internal carotid artery stenosis

Magnetic resonance angiography (MRA) is increasingly used as a noninvasive means to assess internal carotid artery (ICA) stenosis. When used alone, however, MRA may not be sufficiently accurate in certain settings to determine whether ICA disease meets surgical criteria. Although MRA has been recognized to overestimate the degree of stenosis, the authors present two cases in which it severely underestimated arterial stenosis. Two male patients, 70 and 40 years old, respectively, were admitted with crescendo transient ischemic attacks. Their MRA studies suggested nonsurgical lesions of the ICA. After the patients continued to demonstrate clinical evidence of embolic disease, digital subtraction angiography (DSA) was performed on one patient, and the other received a gadolinium contrast-enhanced MRA. These tests revealed critical stenosis in each patient. Each was taken to the operating room for awake carotid endarterectomy with heparin anticoagulation and electroencephalographic monitoring. At surgery, both patients were found to have severely stenosed ICAs with complex plaques. MRA to determine whether ICA stenosis meets surgical criteria may not be sufficiently accurate in certain clinical settings. Additional imaging studies, such as confirmatory digital ultrasonography, MRA with gadolinium contrast, or DSA, may be required to determine the extent of carotid artery stenosis accurately.     

Grading of internal carotid artery stenosis: validation of Doppler/duplex ultrasound criteria and angiography against endarterectomy specimen.

OBJECTIVES: duplex ultrasound has replaced angiography prior to carotid endarterectomy (CEA) in many institutions. However, the indications for CEA are based on angiographically controlled studies and widely accepted ultrasound criteria do not exist. Consequently, the reliability of Doppler and/or duplex ultrasound to predict a high-grade ICA stenosis has to be proven. DESIGN: prospective validation study. MATERIALS: one hundred and fifty carotid bifurcations assessed by ultrasound and selective angiography and 68 acrylat outcasts of carotid specimen after eversion CEA. METHODS: ICA stenosis was measured angiographically according to the ECST criteria. Combined Doppler acoustic standard criteria (CDASC), peak systolic frequency (PSF), peak systolic velocity (PSV) and end-diastolic velocity (EDV) served as criteria for the ultrasound assessment. These criteria and the results of angiography were compared to the degree of ICA stenosis determined by specimen measurements. RESULTS: the median degree of ICA stenosis as assessed by angiography (82%, range 56-97%) and CDASC (83%, range 50-99%) corresponded well to the specimen measurements (80%, range 50-95%). The sensitivity of angiography and CDASC to predict a 70-90% ICA stenosis (ECST criteria) compared to the specimen measurements was 88% and 95%, respectively. The positive predictive value (PPV) reached 92% and 96%, respectively. CDASC were equivalent to angiography and were superior to the best single frequency or velocity parameters. If CDASC do not indicate a >/=70% ICA stenosis in spite of a PSV >/=180 cm/s and/or an EDV >/=50 cm/s, angiography may detect patients with a >70% ICA stenosis. CONCLUSIONS: CDASC are valid in the quantification of high-grade ICA stenosis. They are more reliable than single velocity and/or frequency measurements. However, if velocity criteria and CDASC do not agree, angiography should be performed.     

Overestimation of carotid artery stenosis with magnetic resonance angiography compared with digital subtraction angiography

BACKGROUND AND PURPOSE: Three-dimensional time-of-flight (3D TOF) magnetic resonance angiography (MRA) is generally considered to overestimate the degree of stenosis in the internal carotid artery (ICA) in comparison with the reference standard intraarterial digital subtraction angiography (DSA). We evaluated whether the degree of stenosis was more accurately assessed with 3D TOF MRA if corresponding projections on MRA and DSA were compared instead of comparison of maximal stenosis at MRA with maximal stenosis at DSA. METHODS: From February 1997 to December 1999, we included 186 symptomatic and 17 asymptomatic consecutive patients suspected of having carotid artery stenosis on the basis of clinical presentation and screening with duplex ultrasound scan examination. All patients subsequently underwent DSA and MRA imaging. From each ICA, 12 maximum intensity projections with 3D TOF MRA and two or three projections with DSA were obtained. First, we compared the maximal stenosis at MRA with the maximal stenosis at DSA. Subsequently, we used the stenosis at MRA measured on the projection corresponding with the DSA projection that showed the maximal stenosis. For both strategies, the mean differences in stenosis and sensitivity and specificity for assessment of severe stenosis (70% to 99%) were calculated and compared. RESULTS: The MRA and DSA images of 354 ICAs could be compared. The sensitivity and specificity of MRA with the projection that showed the maximal stenosis were 92.6% (95% CI, 85.3% to 97.0%) and 82.7% (95% CI, 78.1% to 87.3%), respectively. The sensitivity and specificity with the MRA projection, corresponding with the DSA projection showing the maximal stenosis, were 88.3% (95% CI, 81.8% to 94.8%) and 89.6% (95% CI, 85.9% to 93.3%), respectively. The mean difference between maximal stenosis at MRA and DSA was 7.5% (95% CI, 5.2% to 9.9%). The mean difference between stenosis at MRA and DSA in corresponding projections was 0.4% (95% CI, -2.0% to 2.7%). CONCLUSION: If corresponding MRA and intraarterial DSA projections are compared, 3D TOF MRA does not overestimate carotid stenosis.     

Economic evaluation of carotid artery stenting versus carotid endarterectomy for the treatment of carotid artery stenosis

BACKGROUND: The clinical effectiveness of carotid endarterectomy (CEA) is well established. But the economic impact of CEA and carotid artery stenting (CAS) is still uncertain. The objective of this study was to compare hospital costs and reimbursement for CAS and CEA. STUDY DESIGN: We performed a retrospective database analysis on pair-matched patients who underwent CEA (n = 31) and CAS (n = 31) at the Richard M Ross Heart Hospital in Columbus, OH. The hospital's clinical and financial databases were used to obtain patient-specific information and procedural charges. Cost data were generated by applying the hospital's ratio of cost to charges for all DRG charges. The Wilcoxon signed-rank test was used to examine the differences between costs of these procedures. RESULTS: Data are reported as mean +/- SD. The mean age of patients in CAS group was 70.14 years (+/- 1.60 years) versus 68.64 years (+/- 1.75 years) for CEA patients (p < 0.05). The total direct cost associated with CEA ($3,765.12+/-$2,170.82) was significantly lower than the CAS cost ($8,219.71+/-$2,958.55, p < 0.001). The mean procedural cost for CAS ($7,543.61+/-$2,886.54) was significantly higher than that for CEA ($2,720.00+/-$926.38, p < 0.001). The hospital experienced cost savings of $9,690.87 for CEA versus $4,804.79 for CAS from private insurance. Similarly, savings obtained by Medicare-enrolled CEA patients were higher than those for CAS patients ($1,497.79). CONCLUSIONS: CAS is significantly more expensive than CEA, with a major portion of cost attributed to the total procedural cost. The hospital experienced significant savings from CEA procedures compared with CAS under all DRG classifications and insurers. Hospitals must develop new financial strategies and improve the efficiency of infrastructure to make CAS financially viable.     

CT血管造影在诊治骨科软组织肿瘤的作用

[目的]探讨cT血管造影（CTA）及三维重建成像在骨科软组织肿瘤术前诊治的应用价值。[方法]14例软组织肿瘤患者手术前行CTA检查，采用表面遮蔽显示法、容积再现等方法三维重建图像。[结果]三维重建清晰地显示所有肿瘤灶的部位、大小、形态、轮廓的三维结构，特别清晰地显示出肿瘤供血血管、肿瘤与周围重要血管的关系等情况。这些情况均被手术所证实。14例患者手术效果满意，平均随访10．2个月肿瘤无复发。[结论]CT血管造影及三维重建对软组织肿瘤术前评估有独特的价值，有助于手术方案的制定、减少并发症和保证疗效。     

Digital video subtraction angiography and duplex scanning in assessment of carotid artery disease: comparison with conventional angiography

Digital video subtraction angiography (DVSA) and duplex scanning were compared to conventional angiography with regard to their accuracy in quantifying internal carotid artery disease. A classification of 108 carotid arteries available for comparison was made into five groups: normal (14), stenosis to 20% (15), stenosis from 20% to 49% (19), stenosis from 50% to 99% (44), and occlusion (16). The overall agreement corrected for chance (K) for DVSA was 0.738 +/- (SE) 0.049, which was better than for duplex scanning (K = 0.610 +/- 0.055). For hemodynamically significant disease (greater than or equal to 50% diameter reduction), both techniques were highly accurate: DVSA had a sensitivity of 95% (57/60) and a specificity of 92% (44/48); the sensitivity of duplex scanning was also 95% (57/60) and the specificity 85% (41/48). The accuracy in differentiating between high-grade stenosis and occlusion was 98% (59/60) for duplex scanning and 100% (60/60) for DVSA. The most prominent limitation of duplex scanning was its overestimation of disease in normal and minimally diseased arteries. Its specificity for ruling out any degree of disease was only 21% (3/14). DVSA had a poor predictive value of a normal test, 55% (12/22), and was more than one category wrong seven times, while this occurred only three times for duplex scanning. At the present time carotid endarterectomy without conventional angiography is only advocated when there is complete agreement between DVSA and duplex scanning.     

症状性颈动脉狭窄介入治疗的术前评估

目的通过对颈动脉狭窄患者进行综合术前评估，选择介入治疗适应证。方法30例颈动脉狭窄患者，进行MRI、DSA和CTP检查，讨论脑血管狭窄程度、部位、侧支循环和脑血流动力学状态之间的关系。结果患侧与健侧相比，MTT和TTP具有统计学意义（P=0．005和0．002）；狭窄程度与CTP分级之间无明显相关性（r=0．63，P=0．13）；侧支循环越差梗死发生率越高（r=1．0，P=0．017）；灌注越低梗死发生率越高（r=0．999，P=0．033）。结论对于颈动脉狭窄患者应该进行MRI、DSA和CTP的综合分析，以指导临床诊断，治疗及预后等。