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ABSTRACT: BACKGROUND AND PURPOSE: Different flow velocities have been reported after carotid angioplasty with stenting (CAS) than after carotid endarterectomy (CEA). We compared blood flow velocities following CAS and CEA in the International Carotid Stenting Study (ICSS; ISRCTN25337470). MATERIALS AND METHODS: In total, 254 patients (70% male; 129 CAS and 125 CEA) were included. Mean peak systolic velocities (PSVICA) were assessed at baseline, 30 days, 1 and 2 years. Following both treatments, restenosis ≥50% was defined as PSVmean >125 cm s(-1). RESULTS: CAS and CEA resulted in a similar reduction in PSVICA 1 month after treatment. Post-intervention analysis for each treatment separately revealed that PSVICA following CAS increased significantly during follow-up (30 days to 2 years; 22.4 cm s(-1); 95% confidence interval (CI), 14.3 to 30.5). On the contrary, PSVICA following CEA remained relatively stable during follow-up (4.7 cm s(-1); 95% CI, -6.5 to 15.9). When we analysed the increase in PSVICA between both treatments after 2 years of follow-up, no significant interprocedural difference was observed. The internal carotid artery/common carotid artery (ICA/CCA) PSV ratio increased after CAS but not after CEA: 1.2 vs. 1.1 (0.04, 95% CI; -0.16 to 0.25) at 30 days; 1.5 vs. 1.1 (0.39, 95% CI; 0.13 to 0.65) at 1 year; and 1.5 vs. 1.1 (0.36; 95% CI, 0.08 to 0.63) at 2 years. The rate of apparent ipsilateral ICA restenosis >50% was higher following CAS (hazard ratio 2.35; 95% CI, 1.35 to 4.09). CONCLUSION: Two years after carotid revascularisation, no significant interprocedural difference was observed in the increase of PSVICA between CAS and CEA. However, the ICA/CCA ratio increased more following CAS resulting in an apparent higher rate of restenosis following CAS.
European journal of vascular and endovascular surgery: the official journal of the European Society for Vascular Surgery 04/2013; · 2.92 Impact Factor
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ABSTRACT: OBJECTIVES: To investigate whether severity and progression of periventricular and deep white matter lesions (WML) and lacunar infarcts were associated with progression of brain atrophy. METHODS: Within the SMART-MR study, a prospective cohort on MRI changes in patients with symptomatic atherosclerotic disease, 565 patients (57 ± 9 years) without large infarcts had vascular screening and 1.5 T MRI at baseline and after a mean follow-up of 3.9 years. With automated brain segmentation, total brain, cortical gray matter, ventricular, and WML volumes were estimated and expressed relative to intracranial volume (%). Lacunar infarcts were rated manually. RESULTS: Using linear regression analyses adjusted for demographics and vascular risk factors, periventricular WML volume at baseline was associated with greater decrease in cortical gray matter volume (B = -1.73%, 95% confidence interval [CI] -3.15% to -0.30%, per 1% WML volume increase) and greater increase in ventricular volume (B = 0.12%, 95% CI 0.04% to 0.20%). Progression of periventricular WML volume corresponded with a greater decrease in cortical gray matter volume (B = -0.45%, 95% CI -0.9% to 0%) and greater increase in ventricular volume (B = 0.15%, 95% CI 0.1% to 0.2%). Presence of lacunar infarcts was associated with greater decline in total brain volume (B = -0.25%, 95% CI -0.49% to -0.01%) and progression of lacunar infarcts with a greater decrease of total brain (B = -0.30%, 95% CI -0.59% to 0.01%) and cortical gray matter volume (B = -0.81%, 95% CI -1.43% to -0.20%). CONCLUSIONS: In patients with symptomatic atherosclerotic disease, presence and progression of periventricular WML and lacunar infarcts is associated with greater progression of brain atrophy independent of vascular risk factors.
Neurology 10/2012; · 8.31 Impact Factor
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ABSTRACT: Semiautomated methods for ICA stenosis measurements have the potential to reduce interobserver variability and to speed up its analysis. In this study, we estimate the precision and accuracy of a semiautomated measurement for carotid artery stenosis degree and identify and explain differences compared with the manual method.
In this retrospective study involving 90 patients, 2 observers determined the stenosis degree twice, with both the semiautomated and the manual method. Intra- and interobserver correlations were calculated for both methods. The accuracy was estimated by comparing average semiautomated with manual measurements. The semiautomated stenosis calculations were performed using either the minimal or maximal intersection at the reference site. Individual cases with large differences in measurement were retrospectively inspected by 3 observers.
Intra- (R = 0.93, 0.96) and interobserver (R = 0.98) correlations for the semiautomated method were excellent and exceeded the manual performance correlations (R = 0.87, 0.86). The semiautomated measurements correlated well with the manual measurements (R = 0.87), with high specificity of 96% and lower sensitivity of 63%. Large differences were caused by misinterpretations of the semiautomated method associated with calcified plaques, resulting in overestimations of the minimal diameter, underestimation of stenosis degree, and incorrect centerlines. The effect of using the minimal diameter at the reference position resulted in a small, but significant, underestimation of the stenosis degree by the semiautomated method.
The semiautomated method showed an excellent reproducibility and good correlation with manual measurements with a high specificity and lower sensitivity for detecting a significant stenosis. Erroneous semiautomatic stenosis measurements were associated with the presence of calcium.
American Journal of Neuroradiology 12/2011; 33(4):747-54. · 2.93 Impact Factor
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A Altinbas,
M J E van Zandvoort,
E van den Berg,
L M Jongen,
A Algra,
F L Moll, P J Nederkoorn,
W P T M Mali,
L H Bonati,
M M Brown,
L J Kappelle,
H B van der Worp
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ABSTRACT: To compare the effect on cognition of carotid artery stenting (CAS) and carotid endarterectomy (CEA) for symptomatic carotid artery stenosis.
Patients randomized to CAS or CEA in the International Carotid Stenting Study (ICSS; ISRCTN25337470) at 2 participating centers underwent detailed neuropsychological examinations (NPE) before and 6 months after revascularization. Ischemic brain lesions were assessed with diffusion-weighted imaging before and within 3 days after revascularization. Cognitive test results were standardized into z scores, from which a cognitive sumscore was calculated. The primary outcome was the change in cognitive sumscore between baseline and follow-up.
Of the 1,713 patients included in ICSS, 177 were enrolled in the 2 centers during the substudy period, of whom 140 had an NPE at baseline and 120 at follow-up. One patient with an unreliable baseline NPE was excluded. CAS was associated with a larger decrease in cognition than CEA, but the between-group difference was not statistically significant: -0.17 (95% CI -0.38 to 0.03; p = 0.092). Eighty-nine patients had a pretreatment MRI and 64 within 3 days after revascularization. New ischemic lesions were found twice as often after CAS than after CEA (relative risk 2.1; 95% CI 1.0 to 4.4; p = 0.041).
Differences between CAS and CEA in effect on cognition were not statistically significant, despite a substantially higher rate of new ischemic lesions after CAS than after CEA. Classification of Evidence: This study provides Class III evidence that any difference between the effects of CAS and CEA on cognition at 6 months after revascularization is small.
Neurology 08/2011; 77(11):1084-90. · 8.31 Impact Factor
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ABSTRACT: Recent research showed a strong correlation of calcium volume scores with degree of stenosis, suggesting that calcium volume could be used in the diagnosis of carotid artery stenosis. We investigated the accuracy of the use of calcium volume scores to diagnose carotid artery stenosis in our target population of recently symptomatic patients.
Ninety symptomatic patients suspected of having carotid artery stenosis underwent CTA, resulting in images of 159 evaluable arteries. The correlation between calcium volume and degree of stenosis was calculated by using the Pearson correlation coefficient. With thresholds of 0.03 and 0.09 mL, we assessed the diagnostic performance of a calcium volume-based evaluation of stenosis for a previously reported stenosis cutoff of 40% and for the clinically important cutoffs of 50% and 70%.
In our patients series, the calcium volume score was not related to the stenosis degree on the symptomatic side (R = 0.04, P = .7) and was weakly related on the asymptomatic side (R = 0.29, P = .005). The diagnostic accuracy of the calcium volume score to estimate 40% stenosis was relatively low: a sensitivity of 47% or 64% and a specificity of 52% or 82%, for the 0.09 and 0.03 mL thresholds, respectively. The diagnostic accuracy decreased with increasing degree of stenosis.
We could not confirm the previously reported strong correlation of calcium volume with stenosis degree in our population of patients with recent neurologic symptoms. We conclude that in this particular domain, calcium volume cannot be used to estimate the degree of stenosis.
American Journal of Neuroradiology 06/2011; 32(7):1182-7. · 2.93 Impact Factor
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ABSTRACT: In this article, we describe the use of a novel mechanical thrombectomy device aimed at removing a thrombus in patients with acute ischaemic stroke and proximal intracranial arterial occlusion. A self-expandable stent is deployed into the thrombus which results in the immediate restoration of blood flow. After a few minutes, the thrombus will anchor itself onto the mesh of the stent. The stent and the captured thrombus are subsequently retrieved during aspiration of the guiding catheter.
Nederlands tijdschrift voor geneeskunde 01/2011; 155:A2886.
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ABSTRACT: MRI equipment with a magnet having a field strength of 7 Tesla (7-T) has been in use for several years at the University Medical Centre, Utrecht, the Netherlands. 7-Tesla MR imaging provides new opportunities for imaging the brain and its vasculature. The enhanced resolution and the possibilities for angiography of the smallest cerebral vessels without using contrast media are particularly of interest for patients with cerebral small-vessel disease. Microthrombi may be visualised in the perforating cerebral arteries in patients with a lacunar infarct. This technique could have a considerable impact on the classification of several types of lacunar infarcts and could lead to better customised therapies.
Nederlands tijdschrift voor geneeskunde 01/2011; 155:A3232.
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J. Ederle,
J Dobson,
R L Featherstone,
L H Bonati,
H.B. van der Worp,
G.J. de Borst,
T.H. Lo,
P Gaines,
P. J. Dorman,
S Macdonald, [......],
P Van Schil,
M Bosiers,
K Deloose,
E. van Buggenhout,
J. De Letter,
V. Devos,
J. Ghekiere,
G Vanhooren,
P. Astarci,
F. Hammer et al
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ABSTRACT: Background Stents are an alternative treatment to carotid endarterectomy for symptomatic carotid stenosis, but previous trials have not established equivalent safety and efficacy. We compared the safety of carotid artery stenting with that of carotid endarterectomy. Methods The International Carotid Stenting Study (ICSS) is a multicentre, international, randomised controlled trial with blinded adjudication of outcomes. Patients with recently symptomatic carotid artery stenosis were randomly assigned in a 1:1 ratio to receive carotid artery stenting or carotid endarterectomy. Randomisation was by telephone call or fax to a central computerised service and was stratified by centre with minimisation for sex, age, contralateral occlusion, and side of the randomised artery. Patients and investigators were not masked to treatment assignment. Patients were followed up by independent clinicians not directly involved in delivering the randomised treatment. The primary outcome measure of the trial is the 3-year rate of fatal or disabling stroke in any territory, which has not been analysed yet. The main outcome measure for the interim safety analysis was the 120-day rate of stroke, death, or procedural myocardial infarction. Analysis was by intention to treat (ITT). This study is registered, number ISRCTN25337470. Findings The trial enrolled 1713 patients (stenting group, n=855; endarterectomy group, n=858). Two patients in the stenting group and one in the endarterectomy group withdrew immediately after randomisation, and were not included in the ITT analysis. Between randomisation and 120 days, there were 34 (Kaplan-Meier estimate 4.0%) events of disabling stroke or death in the stenting group compared with 27 (3.2%) events in the endarterectomy group (hazard ratio [HR] 1.28, 95% CI 0.77-2.11). The incidence of stroke, death, or procedural myocardial infarction was 8.5% in the stenting group compared with 5.2% in the endarterectomy group (72 vs 44 events; HR 1.69, 1.16-2.45, p=0.006), Risks of any stroke (65 vs 35 events; HR 1.92, 1.27-2.89) and all-cause death (19 vs seven events; HR 2.76, 1.16-6.56) were higher in the stenting group than in the endarterectomy group. Three procedural myocardial infarctions were recorded in the stenting group, all of which were fatal, compared with four, all non-fatal, in the endarterectomy group. There was one event of cranial nerve palsy in the stenting group compared with 45 in the endarterectomy group. There were also fewer haematomas of any severity in the stenting group than in the endarterectomy group (31 vs 50 events; p=0.0197). Interpretation Completion of long-term follow-up is needed to establish the efficacy of carotid artery stenting compared with endarterectomy. In the meantime, carotid endarterectomy should remain the treatment of choice for patients suitable for surgery
The Lancet 01/2010; 375:985. · 38.28 Impact Factor
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ABSTRACT: Previous studies suggest that in patients with ischaemic stroke, White people often present with large-vessel and Black people with small-vessel strokes. This study investigates the relation between large- and small-vessel disease, and ethnicity in White, Black, and Asian patients in Amsterdam, The Netherlands.
In a hospital-based population of 668 patients ethnicity was determined by self-identification. The relation between ethnicity and carotid stenosis, as an indicator of large-vessel disease, was determined using univariate analysis, and adjusted for age, gender, hypertension and smoking. Subsequently the relation between ethnicity and lacunar infarcts, as a manifestation of small-vessel disease, was investigated.
The odds ratio for having carotid stenosis, compared to White patients, was 0.55 (0.23-1.33) for Blacks, 0.53 (0.18-1.52) for Asians, and 0.64 (0.14-2.85) for other ethnicities. The adjusted odds ratio for a non-White patient compared to a White patient was 0.44 (0.19-1.02) (P = 0.05). The non-White patients more often presented with lacunar infarcts compared to Whites.
We found an association between White patients and the presence of carotid artery stenosis. Not only in Black but also in Asian patients the association with carotid artery stenosis was substantially lower. In the non-White population there was an association with lacunar infarcts compared to Whites.
European Journal of Neurology 03/2009; 16(4):522-7. · 3.69 Impact Factor
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ABSTRACT: No data of randomized controlled trials investigating the effect of thrombolysis in patients with ischemic stroke caused by an extracranial dissection are available. Previous case series suggested that thrombolysis in this group of patients is safe and improves outcome, however publication bias may play a role. The purpose of the present study was to describe outcome of consecutive patients with ischemic stroke caused by an extracranial dissection treated with recombinant tissue plasminogen activator (rtPA), derived from a well-defined ischemic stroke cohort.
All consecutive patients with a transient ischemic attack (TIA) or ischemic stroke admitted to the Academic Medical Center Amsterdam between January 1, 2007 and September 1, 2007 were prospectively registered. Cause of TIA/stroke, treatment, and 6-months outcome were recorded.
During the study period 252 patients were evaluated with TIA or ischemic stroke. Eight patients (3%) had an extracranial dissection. Of the six rtPA treated patients, five had good clinical outcome and one patient died. The two patients who were not treated with rtPA, because of minor stroke, had good clinical outcome 6 months after index event.
Treatment with rtPA seems to be safe and feasible in ischemic stroke patients with an extracranial dissection.
European Journal of Neurology 03/2009; 16(5):646-9. · 3.69 Impact Factor
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ABSTRACT: Transient neurological symptoms not fulfilling the criteria for TIA are a problem often encountered in clinical practice. In a large cohort from the Rotterdam study, it was found that these 'transient neurological attacks' (TNA) increase the risk of future cardiovascular events and dementia. However, the group of patients diagnosed with TNA concerns a heterogeneous group with a wide variety of non-focal symptoms. A considerable proportion is probably not caused by vascular (atherothrombotic) disease. Therefore, in our opinion, the reported higher risk for cardiovascular events and dementia should not lead to treatment aimed at secondary prevention in the TNA group as a whole, as it is customary in TIA patients. However, the increased risk for cardiovascular disease, as found in this study, emphasises the need for a thorough search for a possible vascular cause of the symptoms and the presence of cardiovascular risk factors in this complicated group of patients.
Nederlands tijdschrift voor geneeskunde 06/2008; 152(19):1086-7.
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M Smits,
M G M Hunink,
D A van Rijssel,
H M Dekker,
P E Vos,
D R Kool, P J Nederkoorn,
P A M Hofman,
A Twijnstra,
H L J Tanghe,
D W J Dippel
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ABSTRACT: Functional outcome in patients with minor head injury with neurocranial traumatic findings on CT is largely unknown. We hypothesized that certain CT findings may be predictive of poor functional outcome. Materials and
All patients from the CT in Head Injury Patients (CHIP) study with neurocranial traumatic CT findings were included. The CHIP study is a prospective, multicenter study of consecutive patients, > or =16 years of age, presenting within 24 hours of blunt head injury, with a Glasgow Coma Scale (GCS) score of 13-14 or a GCS score of 15 and a risk factor. Primary outcome was functional outcome according to the Glasgow Outcome Scale (GOS). Other outcome measures were the modified Rankin Scale (mRS), the Barthel Index (BI), and number and severity of postconcussive symptoms. The association between CT findings and outcome was assessed by using univariable and multivariable regression analysis.
GOS was assessed in 237/312 patients (76%) at an average of 15 months after injury. There was full recovery in 150 patients (63%), moderate disability in 70 (30%), severe disability in 7 (3.0%), and death in 10 (4.2%). Outcome according to the mRS and BI was also favorable in most patients, but 82% of patients had postconcussive symptoms. Evidence of parenchymal damage was the only independent predictor of poor functional outcome (odds ratio = 1.89, P = .022).
Patients with neurocranial complications after minor head injury generally make a good functional recovery, but postconcussive symptoms may persist. Evidence of parenchymal damage on CT was predictive of poor functional outcome.
American Journal of Neuroradiology 04/2008; 29(3):506-13. · 2.93 Impact Factor
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M Smits,
M G M Hunink, P J Nederkoorn,
H M Dekker,
P E Vos,
D R Kool,
P A M Hofman,
A Twijnstra,
G G de Haan,
H L J Tanghe,
D W J Dippel
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ABSTRACT: A history of loss of consciousness (LOC) or post-traumatic amnesia (PTA) is commonly considered a prerequisite for minor head injury (MHI), although neurocranial complications also occur when LOC/PTA are absent, particularly in the presence of other risk factors. The purpose of this study was to evaluate whether known risk factors for complications after MHI in the absence of LOC/PTA have the same predictive value as when LOC/PTA are present.
A prospective multicentre study was performed in four university hospitals between February 2002 and August 2004 of consecutive blunt head injury patients (> or = 16 years) presenting with a normal level of consciousness and a risk factor. Outcome measures were any neurocranial traumatic CT finding and neurosurgical intervention. Common odds ratios (OR) were estimated for each of the risk factors and tested for homogeneity.
2462 patients were included: 1708 with and 754 without LOC/PTA. Neurocranial traumatic findings on CT were present in 7.5% and were more common when LOC/PTA was present (8.7%). Neurosurgical intervention was required in 0.4%, irrespective of the presence of LOC/PTA. ORs were comparable across the two subgroups (p>0.05), except for clinical evidence of a skull fracture, with high ORs both when LOC/PTA was present (OR = 37, 95% CI 17 to 80) or absent (OR = 6.9, 95% CI 1.8 to 27). LOC and PTA had significant ORs of 1.9 (95% CI 1.0 to 2.7) and 1.7 (95% CI 1.3 to 2.3), respectively.
Known risk factors have comparable ORs in MHI patients with or without LOC or PTA. MHI patients without LOC or PTA need to be explicitly considered in clinical guidelines.
Journal of neurology, neurosurgery, and psychiatry 01/2008; 78(12):1359-64. · 4.87 Impact Factor
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ABSTRACT: A recent trial revealed a reduction in ischaemic infarcts after carotid endarterectomy in patients with asymptomatic carotid stenosis. However, the number needed to treat (NNT) was 19 to prevent one stroke in 5 years, a modest effect in comparison to the trials with symptomatic patients (a NNT of only 6 in patients with a symptomatic stenosis of 70-99%). Furthermore, the number of surgical complications outweighs the benefits of surgery during the first two years after treatment. Finally, the benefits also included the prevention of contralateral strokes, whereas it is unlikely that these are prevented by endarterectomy. Therefore, endarterectomy should not be performed routinely in asymptomatic persons.
Nederlands tijdschrift voor geneeskunde 11/2006; 150(41):2259.
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ABSTRACT: A 3D model-based approach for quantification of vascular morphology from several MRA acquisition protocols was evaluated. Accuracy, reproducibility, and influence of the image acquisition techniques were studied via in vitro experiments with ground truth diameters and the measurements of two expert readers as reference. The performance of the method was similar to or more accurate than the manual assessments and reproducibility was also improved. The methodology was applied to stenosis grading of carotid arteries from CE MRA data. In 11 patients, the approach was compared to manual scores (NASCET criterion) on CE MRA and DSA images, with the result that the model-based technique correlates better with DSA than the manual scores. Spearman's correlation coefficient was 0.91 (P < 0.001) for the model-based technique and DSA vs. 0.80 and 0.84 (P < 0.001) between the manual scores and DSA. From the results it can be concluded that the approach is a promising objective technique to assess geometrical vascular parameters, including degree of stenosis. Magn Reson Med 45:311-322, 2001.
Magnetic Resonance in Medicine 03/2001; 45(2):311-22. · 2.96 Impact Factor
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ABSTRACT: A model-based technique for quantitative analysis of
three-dimensional magnetic resonance angiography (MRA) is presented. The
model consists of a deformable B-spline representation of the central
vessel axis and the vessel wall. An efficient interaction mechanism to
initialize the models in a three-dimensional setting is devised. Two
novel image features are introduced in order to deform the central
vessel axis and the vessel wall model respectively. A segmental
optimization scheme for deforming the B-spline vessel wall model is
introduced. Finally, the paper presents results on clinical contrast
enhanced (CE) MRA of 19 carotid arteries. Percentages of stenosis
obtained with the authors' technique are compared to those of two
experts using caliper measurements on Maximum Intensity Projection (MIP)
CE MRA, and Digital Subtraction Angiography (DSA) as standard of
reference
Mathematical Methods in Biomedical Image Analysis, 2000. Proceedings. IEEE Workshop on; 02/2000
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ABSTRACT: Purpose: To determine the optimal peak systolic velocity (PSV) threshold at duplex ultrasonography (US) required to establish the need for carotid endarterectomy in symptomatic patients on the basis of the long-term cost-effectiveness outcomes of diagnostic testing and subsequent treatment. Materials and Methods: From January 1997 through January 2000, a prospective medical ethics committee-approved multicenter study was conducted. After giving informed consent, patients with amaurosis fugax, transient ischemic attack, or minor stroke who underwent duplex US and digital subtraction angiography were included in the study. Selective ipsilateral carotid angiograms were obtained in at least three planes. Arteries that were nearly or totally occluded at duplex US were excluded because the PSV cannot be reliably measured in these vessels. Receiver operating characteristic (ROC) curves were constructed for the diagnoses of 70%-99% and 50%-99% sterroses. Optimal likelihood ratios were calculated on the basis of lifetime costs and quality-adjusted life-years derived at cost-effectiveness analysis and the prevalence of disease. The associated optimal sensitivities, specificities, and PSV thresholds were derived from the ROC curves. Results: In this clinical study, 350 patients were included. The nonoccluded arteries in a total of 236 patients were assessable for ROC analysis. For the diagnosis of 70%-99% stenosis, the optimal likelihood ratio was 0.21, which was associated with a PSV threshold of 220 cm/sec, a sensitivity of 97% (127 of 131 patients; 95% confidence interval [CI]: 94%, 100%), and a specificity of 48% (50 of 105 patients; 95% CI: 38%, 57%). For the diagnosis of 50%-99% stenosis, the optimal likelihood ratio was 0.38, which was associated with a PSV threshold of 180 cm/sec, a sensitivity of 95% (182 of 191 and a specificity of 69% (31 of 45 patients; 95% CI: 55%, 82%). Conclusion: On the basis of the lifetime outcomes of diagnostic testing and subsequent treatment, the optimal PSV thresholds for the diagnosis of 70%-99% and 50%-99% carotid artery sterroses in patients with amaurosis fugax, transient ischemic attack, or minor stroke were 220 cm/sec and 180 cm/sec, respectively. (c) RSNA, 2005
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