Comparison of ultrasonography, CT angiography, and digital subtraction angiography in severe carotid stenoses

Differential Assessment of Internal Jugular Vein Stenosis in Patients Undergoing CT and MRI with Contrast

OBJECTIVE

Internal Jugular Vein Stenosis (IJVS) is hypothesized to play a role in the pathogenesis of diverse neurological diseases. We sought to evaluate differences in IJVS assessment between CT and MRI in a retrospective patient cohort.

METHODS

We included consecutive patients who had both MRI of the brain and CT of the head and neck with contrast from 1 June 2021 to 30 June 2022 within the same admission. The degree of IJVS was categorized into five grades (0-IV).

RESULTS

A total of 35 patients with a total of 70 internal jugular (IJ) veins were included in our analysis. There was fair intermodality agreement in stenosis grades (κ = 0.220, 95% C.I. = [0.029, 0.410]), though categorical stenosis grades were significantly discordant between imaging modalities, with higher grades more frequent in MRI (χ2 = 27.378, p = 0.002). On CT-based imaging, Grade III or IV stenoses were noted in 17/70 (24.2%) IJs, whereas on MRI-based imaging, Grade III or IV stenoses were found in 40/70 (57.1%) IJs. Among veins with Grade I-IV IJVS, MRI stenosis estimates were significantly higher than CT stenosis estimates (77.0%, 95% C.I. [35.9-55.2%] vs. 45.6%, 95% C.I. [35.9-55.2%], p < 0.001).

CONCLUSION

MRI with contrast overestimates the degree of IJVS compared to CT with contrast. Consideration of this discrepancy should be considered in diagnosis and treatment planning in patients with potential IJVS-related symptoms.

Risk factors and the CCTA application in patients with vulnerable coronary plaque in type 2 diabetes: a retrospective study

BACKGROUND

Diabetes is an independent risk factor for cardiovascular disease. The purpose of this study was to identify the risk factors for vulnerable coronary plaques (VCPs), which are associated with adverse cardiovascular events, and to determine the value of coronary CT angiography (CCTA) in patients with type 2 diabetes mellitus (T2DM) and VCPs.

METHODS

Ninety-eight T2DM patients who underwent CCTA and intravascular ultrasound (IVUS) were retrospectively included and analyzed. The patients were grouped and analyzed according to the presence or absence of VCPs.

RESULTS

Among the patients with T2DM, time in range [TIR {the percentage of time blood glucose levels were in the target range}] (OR = 0.93, 95% CI = 0.89-0.96; P < 0.001) and the high-density lipoprotein-cholesterol (HDL-C) concentration (OR = 0.24, 95% CI = 0.09-0.63; P = 0.04) were correlated with a lower risk of VCP, but the triglycerides (TG) concentration was correlated with a higher risk of VCP (OR = 1.79, 95% CI = 1.01-3.18; P = 0.045). The area under the receiver operator characteristic curve (AUC) of TIR, and HDL-C and TG concentrations were 0.76, 0.73, and 0.65, respectively. The combined predicted AUC of TIR, and HDL-C and TG concentrations was 0.83 (P < 0.05). The CCTA sensitivity, specificity, false-negative, and false-positive values for the diagnosis of VCP were 95.74%, 94.12%, 4.26%, and 5.88%, respectively. The identification of VCP by CCTA was positively correlated with IVUS (intraclass correlation coefficient [ICC] = 0.90).

CONCLUSIONS

The TIR and HDL-C concentration are related with lower risk of VCP and the TG concentration was related with higher risk of VCP in patients with T2DM. In clinical practice, TIR, HDL-C and TG need special attention in patients with T2DM. The ability of CCTA to identify VCP is highly related to IVUS findings.

Peak systolic velocity ratio for evaluation of internal carotid artery stenosis correlated with plaque morphology: substudy results of the ANTIQUE study

Background

Accurate assessment of carotid stenosis severity is important for proper patient management. The present study aimed to compare the evaluation of carotid stenosis severity using four duplex sonography (DUS) measurements, including peak systolic velocity (PSV), PSV ratio in stenosis and distal to stenosis (PSVICA/ICA ratio), end-diastolic velocity (EDV), and B-mode, with computed tomography angiography (CTA), and to evaluate the impact of plaque morphology on correlation between DUS and CTA.

Methods

Consecutive patients with carotid stenosis of ≥40% examined using DUS and CTA were included. Plaque morphology was also determined using magnetic resonance imaging. Spearman's correlation and Kendall's rank correlation were used to evaluate the results.

Results

A total of 143 cases of internal carotid artery stenosis of ≥40% based on DUS were analyzed. The PSVICA/ICA ratio showed the highest correlation [Spearman's correlation r = 0.576) with CTA, followed by PSV (r = 0.526), B-mode measurement (r = 0.482), and EDV (r = 0.441; p < 0.001 in all cases]. The worst correlation was found for PSV when the plaque was calcified (r = 0.238), whereas EDV showed a higher correlation (r = 0.523). Correlations of B-mode measurement were superior for plaques with smooth surface (r = 0.677), while the PSVICA/ICA ratio showed the highest correlation in stenoses with irregular (r = 0.373) or ulcerated (r = 0.382) surfaces, as well as lipid (r = 0.406), fibrous (r = 0.461), and mixed (r = 0.403; p < 0.01 in all cases) plaques. Nevertheless, differences between the mentioned correlations were not statistically significant (p > 0.05 in all cases).

Conclusion

PSV, PSVICA/ICA ratio, EDV, and B-mode measurements showed comparable correlations with CTA in evaluation of carotid artery stenosis based on their correlation with CTA results. Heavy calcifications and plaque surface irregularity or ulceration negatively influenced the measurement accuracy.

Development and Evaluation of a Multifrequency Ultrafast Doppler Spectral Analysis (MFUDSA) Algorithm for Wall Shear Stress Measurement: A Simulation and In Vitro Study

Cardiovascular pathology is the leading cause of death and disability in the Western world, and current diagnostic testing usually evaluates the anatomy of the vessel to determine if the vessel contains blockages and plaques. However, there is a growing school of thought that other measures, such as wall shear stress, provide more useful information for earlier diagnosis and prediction of atherosclerotic related disease compared to pulsed-wave Doppler ultrasound, magnetic resonance angiography, or computed tomography angiography. A novel algorithm for quantifying wall shear stress (WSS) in atherosclerotic plaque using diagnostic ultrasound imaging, called Multifrequency ultrafast Doppler spectral analysis (MFUDSA), is presented. The development of this algorithm is presented, in addition to its optimisation using simulation studies and in-vitro experiments with flow phantoms approximating the early stages of cardiovascular disease. The presented algorithm is compared with commonly used WSS assessment methods, such as standard PW Doppler, Ultrafast Doppler, and Parabolic Doppler, as well as plane-wave Doppler. Compared to an equivalent processing architecture with one-dimensional Fourier analysis, the MFUDSA algorithm provided an increase in signal-to-noise ratio (SNR) by a factor of 4-8 and an increase in velocity resolution by a factor of 1.10-1.35. The results indicated that MFUDSA outperformed the others, with significant differences detected between the typical WSS values of moderate disease progression (p = 0.003) and severe disease progression (p = 0.001). The algorithm demonstrated an improved performance for the assessment of WSS and has potential to provide an earlier diagnosis of cardiovascular disease than current techniques allow.

Evaluating the length, diameter, and stenosis of deep circumflex iliac artery and neighboring arteries based on digital subtraction angiography

BACKGROUND

The vascularized iliac bone crest flap offers excellent usable bone in terms of volume and quality. Its nourishing vessel, the deep circumflex iliac artery (DCIA), although relatively short, is reliable vessel. Digital subtraction angiography presents still the gold standard for diagnostic purpose. However, computed tomography (CT) and magnetic resonance imaging (MRI) angiography is used for preoperative planning with low morbidity. The purpose of this study is to evaluate the gainable information using digital subtraction angiography (DSA) as compared to other imaging modalities.

MATERIALS AND METHODS

We evaluated information gainable from standard DSA of 130 consecutive patients (average age was 69.5 years [range 18-90 years]) concerning topography, dimension, and condition of the vessel wall. We looked for differences considering gender and side.

RESULTS

DCIA could not be followed in the periphery constantly in all cases due to the small, illustrated field. Arteriosclerotic changes showed to be very low in DCIA as compared to the neighboring vessels. Diabetes mellitus and smoking had a significant impact on vessel condition. DCIA branched off into its main two branches early after 40 mm (11%), after 40-60 mm (30%), or late after 60 mm (59%). DCIA showed to be least affected by different risk factors that reported to affect the vessel condition.

CONCLUSIONS

We present additional detailed topographic anatomy of DCIA and its variation that can be used intraoperative guide to harvest the flap and teaching purpose. Standard DSA delivers valuable preoperative data regarding stenosis in addition to the topographic anatomy of the flap pedicle. However, imaging of the distal parts of the DCIA, nourishing the skin paddle is limited by the detector field used. For a full imaging of both DCIAs from the origin to the perforators, the intraarterial injection of contrast medium, as applied in DSA, could be combined with different imaging modalities like CT-angiography.

Evaluation of neurosonology versus digital subtraction angiography in acute stroke patients

Stroke is one of the most common neurological disorders with a high incidence in Middle-eastern regions. We aimed to assess the diagnostic accuracy of neurovascular ultrasound to detect of cerebral artery stenosis compared to digital subtraction angiography (DSA) as a gold standard method. Eighty patients presenting with symptoms of cerebral ischemia were enrolled in the study. They were examined by cervical color Doppler ultrasound and TCCS to determine stenosis of extracranial and intracranial arteries, respectively. DSA was performed 24-48 h after the initial examination. The sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of neurovascular ultrasound in comparison to DSA were calculated. The agreement between the two methods was determined by kappa statistics. Eighty patients (60% male, 40% female) with a mean age of 61.32 ± 12.6 years were included. In 65% of patients, stenosis in carotid artery caused ischemic symptoms. We did not observe any stenosis in anterior cerebral artery, posterior cerebral artery and basilar artery in patients. The agreement between the neurovascular ultrasound and DSA in various arterial vessels was 0.9 for common carotid artery, 0.86 for internal carotid artery, 0.78 for middle cerebral artery, and 0.86 for vertebral artery. The sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and kappa value of the neurovascular ultrasound for detecting stenosis regarding the arterial segments were 84.8%, 81%, 92.6%, 65.4%, 83.8, and 0.71, respectively. In conclusion, the neurovascular ultrasound is a valuable, non-invasive, and repeatable method to investigate cerebral artery stenosis with high diagnostic accuracy.

The Clinical Contribution of Neurovascular Ultrasonography in Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Patients with acute ischemic stroke receive computed tomography angiogram (CTA) and digital subtraction angiogram (DSA) for clinical evaluation. Current guidelines lack in defining indications for transcranial Doppler (TCD) and/or carotid duplex ultrasonography (CUS) in acute stroke evaluation or follow-up cerebrovascular imaging after reperfusion. We investigated the clinical utility of performing additional TCD/CUS after reperfusion in guiding postacute care stroke management.

METHODS

Retrospective review of acute ischemic stroke patients admitted to a comprehensive stroke center with CTA head and neck and/or DSA followed by TCD/CUS. Cases were reviewed by two authors to determine if TCD/CUS provided additional diagnostic information to aid management. A nominal group process, using a third author, achieved consensus in cases of disagreements.

RESULTS

Only 25 of 198 patients had CTA or DSA followed by TCD/CUS. Ten (40%) cases showed new clinical information from CUS aiding management. Of those with TCD, 5 patients (22.7%) had findings that impacted management. These clinical scenarios included detection of mobile thrombus requiring anticoagulation; distinguishing carotid near-occlusion from occlusion; confirming hemodynamic significance of intra/extracranial stenosis helping emergent stenting/endarterectomy; detecting hyperperfusion on TCDs causing symptoms; and establishing chronicity of carotid stenosis based on collateral flow patterns, which deferred further intervention.

DISCUSSION

Our experience shows that TCD/CUS may offer additional diagnostic information assisting postacute care management in small subset of patients with acute ischemic stroke. Larger studies are needed to research the clinical impact and cost-effectiveness of additional imaging and inform clinical guidelines for selecting patients who will benefit from these additional studies.

Assessment of Age-related Oxygenation Changes in Calf Skeletal Muscle by Photoacoustic Imaging: A Potential Tool for Peripheral Arterial Disease

Peripheral artery disease is often asymptomatic, and various imaging and nonimaging techniques have been used for assessment and monitoring treatments. This study is designed to demonstrate the ability of photoacoustic imaging to noninvasively determine changes in tissue oxygenation that occur in mice's hind limb skeletal muscle as they age. Mice from two age cohorts were scanned bilaterally with a pulsed laser. The photoacoustic signal was unmixed to generate a parametric map of estimated oxygen saturation and then overlaid on grayscale ultrasound images. Tissue oxygenation measured in young and old mice was compared. Photoacoustic imaging visually and quantitatively showed the decrease in skeletal muscle oxygenation that occurs with age. Percent tissue oxygenation decreased from 30.2% to 3.5% (p < 0.05). This reduction corresponded to reduced fractional area of oxygenation, which decreased from 60.6% to 6.0% (p < 0.05). The change in oxygenation capacity of the still active vascular regions was insignificant (p > 0.05). Intrasubject, intra-, and interobserver comparisons showed low variability in measurements, exhibited by high regression and intraclass correlations exceeding 0.81 for all ages. The decrease in oxygenation detected by photoacoustic imaging paralleled the known oxygenation decrease observed in aging tissues, demonstrating that photoacoustic imaging can assess age-related changes in a mouse calf muscle. These intramuscular changes could potentially act as a strong diagnostic marker for peripheral artery disease. This study thus opens the doors for a novel, affordable, noninvasive method of evaluation free of radiation or exogenous material.

Cerebral misery perfusion due to carotid occlusive disease

Purpose

Cerebral misery perfusion (CMP) is a condition where cerebral autoregulatory capacity is exhausted, and cerebral blood supply in insufficient to meet metabolic demand.

We present an educational review of this important condition, which has a range of clinical manifestations.

Method

A non-systematic review of published literature was undertaken on CMP and major cerebral artery occlusive disease, using Pubmed and Sciencedirect.

Findings

Patients with CMP may present with strokes in watershed territories, collapses and transient ischaemic attacks or episodic movements associated with an orthostatic component. While positron emission tomography is the gold standard investigation for misery perfusion, advanced MRI is being increasingly used as an alternative investigation modality. The presence of CMP increases the risk of strokes. In addition to the devastating effect of stroke, there is accumulating evidence of impaired cognition and quality of life with carotid occlusive disease (COD) and misery perfusion. The evidence for revascularisation in the setting of complete carotid occlusion is weak. Medical management constitutes careful blood pressure management while addressing other vascular risk factors.

Discussion

The evidence for the management of patients with COD and CMP is discussed, together with recommendations based on our local experience. In this review, we focus on misery perfusion due to COD.

Conclusion

Patients with CMP and COD may present with a wide-ranging clinical phenotype and therefore to many specialties. Early identification of patients with misery perfusion may allow appropriate management and focus on strategies to maintain or improve cerebral blood flow, while avoiding potentially harmful treatment.

Chinese Atherosclerosis Risk Evaluation (CARE II) study: a novel cross-sectional, multicentre study of the prevalence of high-risk atherosclerotic carotid plaque in Chinese patients with ischaemic cerebrovascular events-design and rationale

Background

Carotid atherosclerotic plaque is identified as one of the main sources of ischaemic stroke. However, the prevalence of carotid high-risk atherosclerotic plaque in Chinese patients with ischaemic cerebrovascular events has been inconsistently reported and needs to be investigated in a large population.

Objectives

The primary objective of CARE II study was to determine the prevalence and characteristics of high-risk features of atherosclerotic plaques in the carotid arteries in Chinese patients with recent ischaemic stroke or transient ischaemia attack (TIA). The relationship between carotid plaque features and cerebral infarcts, the differences of carotid plaque patterns among different regions of China and the gender specific characteristics of carotid plaque will be also determined.

Study design

The CARE II study will enrol 1000 patients with recent ischaemic stroke or TIA and carotid plaque from 13 hospitals and medical centres across China. In this cross-sectional, non-randomised, observational, multicentre study, all patients will undergo carotid artery MRI of bilateral carotid arteries and routine brain MRI with standardised protocols. The MRI will be interpreted at core reading centres to evaluate the characteristics of morphology and compositions of carotid plaque.

Conclusions

This is a cross-sectional, multicentre study to investigate the prevalence and characteristics of high-risk atherosclerotic carotid plaque in Chinese patients with stroke and TIA by using high-resolution MRI of vessel wall. This trial is sufficiently powered to demonstrate the prevalence of carotid high-risk plaque and to explore regional differences in Chinese patients who suffered stroke.

Trial registration number

NCT02017756.

Brain Vascular Imaging Techniques

Recent major improvements in a number of imaging techniques now allow for the study of the brain in ways that could not be considered previously. Researchers today have well-developed tools to specifically examine the dynamic nature of the blood vessels in the brain during development and adulthood; as well as to observe the vascular responses in disease situations in vivo. This review offers a concise summary and brief historical reference of different imaging techniques and how these tools can be applied to study the brain vasculature and the blood-brain barrier integrity in both healthy and disease states. Moreover, it offers an overview on available transgenic animal models to study vascular biology and a description of useful online brain atlases.

Combining carotid endarterectomy with off-pump coronary artery bypass graft surgery is safe and effective

Background:

We, as neurologists, are frequently consulted to give neurological clearance for surgery in patients who are undergoing coronary artery bypass graft (CABG) surgery and have suffered from stroke or transient ischemic attack (TIA) in past. Similarly clearance is also sought in another group of patients who, though have not suffered from stroke or TIA, but found to have significant carotid stenosis on routine screening prior to surgery. Cardiac surgeons and anesthetists want to know the risk of perioperative stroke in such patients and should carotid endarterectomy (CEA) be done along with CABG. In absence of any clear-cut guideline, neurologists often fail to give any specific recommendation.

Aim:

To find out safety and efficacy of synchronous CEA in patients undergoing CABG.

Design:

Retrospective study.

Materials and Methods:

Out of 3,700 patients who underwent CABG, 150 were found to have severe carotid stenosis of >70%. Out of this, 46 patients with >80% stenosis (three symptomatic and 43 asymptomatic) and one patient with >70% symptomatic carotid stenosis (TIA within last 2 weeks) were taken for simultaneous CEA along with CABG. These three symptomatic carotid patients had suffered from stroke within last 6 months.

Results:

One patient with asymptomatic near total occlusion of carotid artery suffered from hyperperfusion syndrome. None suffered from ischemic stroke, myocardial infarction (MI), or death during perioperative period.

Conclusion:

Combining CEA along with CABG is a safe and effective procedure.

CT angiography of the lower extremity and coronary arteries using 256-section CT: a preliminary study

AIM

To investigate the possible use of a 256-section computed tomography (CT) prospective electrocardiography (ECG)-gated wide volume scanning protocol for combined angiography of the lower extremity and coronary arteries, after a single injection of contrast medium, in patients with lower extremity peripheral arterial disease (PAD).

MATERIALS AND METHODS

Thirty-four patients with suspected PAD underwent CT angiography (CTA) with a prospective ECG-gated protocol that covered the level of the tracheal bifurcation to the foot sole. Digital subtraction angiography (DSA) of the lower extremity arteries was performed on patients requiring therapeutic intervention. Image quality and stenosis of the coronary and lower extremity arteries were assessed.

RESULTS

A total of 93.1% of the coronary segments were adequate for diagnosis. 17 (50%) patients showed coronary artery stenosis ≥50%. A total of 95.8% of the lower extremity arterial segments were adequate for diagnosis. Twenty-eight patients with severe lower extremity arterial stenosis or occlusion underwent DSA. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CTA for the detection of significant lower arterial stenosis (≥50%) was 94.8%, 97.2%, 95.3%, 96.9%, and 96.3%, respectively.

CONCLUSION

Using the prospective ECG-gated wide volume CTA protocol, images of the coronary and lower extremity arteries suitable for diagnosis can be acquired simultaneously after a single injection of contrast agent. In addition to accurately diagnosing PAD, combined angiography may be used to screen for coronary heart disease in patients with PAD.

Intramural location and size of arterial calcification are associated with stenosis at carotid bifurcation

PURPOSE

The purpose of this study was to investigate the association between internal carotid artery (ICA) stenosis and intramural location and size of calcification at the ICA origins and the origins of the cervical arteries proximal to the ICA.

METHOD

A total of 1139 ICAs were evaluated stenosis and calcification on the multi-detector row CT angiography. The intramural location was categorized into none, outside and inside location. The calcification size was evaluated on the 4-point grading scale. The multivariate analyses were adjusted for age, serum creatinine level, hypertension, hyperlipidemia, diabetes mellitus, smoking and alcohol habits.

RESULTS

Outside calcification at the ICA origins showed the highest multivariate odds ratio (OR) for the presence of ICA stenosis (30.0) and severe calcification (a semicircle or more of calcification at the arterial cross-sectional surfaces) did the second (14.3). In the subgroups of >70% ICA stenosis, the multivariate OR of outside location increased to 44.8 and that of severe calcification also increased to 32.7. Four of 5 calcified carotid plaque specimens extracted by carotid endarterectomy were histologically confirmed to be calcified burdens located outside the internal elastic lamia which were defined as arterial medial calcification.

CONCLUSIONS

ICA stenosis was strongly associated with severe calcification located mainly outside the carotid plaque. Outside calcification at the ICA origins should be evaluated separately from inside calcification, as a marker for the ICA stenosis. Additionally, we found that calcification at the origins of the cervical arteries proximal to the ICA was significantly associated with the ICA stenosis.

Detection of intracranial arterial stenosis using transcranial color-coded duplex sonography, computed tomographic angiography, and digital subtraction angiography

OBJECTIVES

The aim of this retrospective study was to compare intracranial arterial stenosis in patients with stroke using 3 different methods: transcranial color-coded duplex sonography, computed tomographic (CT) angiography, and digital subtraction angiography in a common clinical practice.

METHODS

Sixty-seven patients (47 male and 20 female; age range, 23-79 years; mean age ± SD, 62.0 ± 9.5 years) were enrolled in this study over 40 months. All patients underwent examinations of the intracranial arteries using transcranial color-coded sonography, CT angiography, and digital subtraction angiography. Findings were divided into 4 groups: normal, mild stenosis (<50%), severe stenosis (50%-99%), and occlusion.

RESULTS

Because of technical reasons or an insufficient bone window, 465 of 536 arterial segments in 67 patients were evaluated; 12 stenotic and 15 occluded segments were detected using digital subtraction angiography. The sensitivity, specificity, positive predictive value, and negative predictive value of transcranial color-coded sonography and CT angiography in comparison with digital subtraction angiography as a reference standard were 88.9%, 94.8%, 51.1%, and 99.3% and 81.5%, 98.7%, 78.6%, and 98.6%, respectively. The agreement between transcranial color-coded sonography and CT angiography was 93.8% (κ = 0.559); between transcranial color-coded sonography and digital subtraction angiography, it was 93.9% (κ = 0.588); and between CT angiography and digital subtraction angiography, it was 96.6% (κ = 0.697).

CONCLUSIONS

Moderate agreement was found between CT angiography, transcranial color-coded sonography, and digital subtraction angiography in the evaluation of intracranial stenosis. Computed tomographic angiography and digital subtraction angiography are sufficient for assessment of the diagnosis.

[Diagnostic dilemmas of multislice CT angiography in the evaluation of the degree of common carotid artery stenosis]

INTRODUCTION

Multislice CT angiography (CTA) is a noninvasive and quick technique to image carotid artery stenosis, as well as intracerebral vasculature. Modern multidetector CTA produces images with a high resolution of, not only the contrast-filled lumen, but also of the vessel wall and the surrounding soft tissues. Multiple studies have verified the ability of CTA to provide an accurate representation of the degree of carotid stenosis in comparison to digital subtraction angiography, both for moderate and high-grade stenosis. Because of its fast and accurate vessel imaging, CT angiography is increasingly used in the assessment of carotid artery stenosis.

CASE OUTLINE

A 37-year-old female patient was admitted at the Vascular Surgery Clinic of the Institute for Cardiovascular Diseases "Dedinje", Belgrade, for angiography and endovascular procedure of a high-grade stenosis of the left common carotid artery based on Multislice CT findings brought by the patient. She complained of problems which we considered to be the result of cerebral circulation ischemia. After detailed diagnostic procedures, we concluded that no pathological lesions could be verified either on the left common carotid artery or other supraaortic branches.Therefore, the patient was discharged for further neurological examinations.

CONCLUSION

Although Multislice CTA has many advantages over classical angiography, its validity should be taken with reserve, especially in younger patients.

Contrast-enhanced MR angiography is not more accurate than unenhanced 2D time-of-flight MR angiography for determining > or = 70% internal carotid artery stenosis

BACKGROUND AND PURPOSE

Internal carotid artery (ICA) atheromatous disease is an important cause of ischemic stroke, and endarterectomy or stent placement is typically indicated for symptomatic patients with > or = 70% stenosis. Our purpose was to compare contrast-enhanced MR angiography (CE-MRA) with unenhanced 2D time-of-flight MR angiography (2D TOF MRA) in detecting hemodynamically significant ICA stenosis, by using CT angiography (CTA) as the reference standard.

MATERIALS AND METHODS

This was an institutional review board-approved retrospective study. We identified 177 consecutive patients (354 ICAs) who received correlative CE-MRA, 2D TOF MRA, and CTA. Two neuroradiologists blinded to the CTA data graded the degree of ICA stenosis according to a 5-point scale. Additionally, luminal signal-intensity characteristics including 1) signal intensity drop-out, 2) distal-vessel narrowing, and 3) distal-vessel signal-intensity reduction were recorded. MRA results were correlated with those of CTA, and receiver-operating-characteristic (ROC) curves were constructed.

RESULTS

On CTA, there were 55 ICAs with and 299 without > or = 70% stenosis. CE-MRA was 84% sensitive and 96% specific for detecting > or = 70% stenosis; 2D TOF MRA was 80% sensitive and 95% specific. The area under the ROC curve was 0.97 for CE-MRA and 0.95 for 2D TOF MRA (P = .51, not significant). For both MRA studies, each of the luminal signal-intensity characteristics had high specificity (> 98%) but poor-to-mild sensitivity (35%-66%) in detecting > or = 70% stenosis.

CONCLUSIONS

Although it is established that CE-MRA more accurately delineates neurovascular anatomy than does unenhanced 2D TOF MRA, the administration of gadolinium did not offer a significant advantage in distinguishing surgically treatable ICA stenosis. This conclusion may be important in patients with contraindications to gadolinium.

Mandatory diagnostic angiography for carotid artery stenosis prior to carotid artery intervention

INTRODUCTION

Revascularization is an important strategy for reducing stroke risk in patients with severe carotid atherosclerosis. Magnetic resonance angiography (MRA) and/or carotid ultrasound have traditionally been used as the only diagnostic modalities prior to revascularization. Patients undergoing CEA frequently have no further assessments of carotid anatomy prior to surgery. Evaluation with carotid ultrasound and MRA can often overestimate the degree of stenosis. We sought to determine if noninvasive imaging was sufficient for determining whether a patient should be referred for carotid intervention.

METHODS

We performed an analysis of 101 patients referred for carotid artery stenting (CAS). All patients had previously been evaluated with carotid ultrasound and 94% had undergone MRA as well. We sought to determine if noninvasive diagnostic imaging for carotid stenosis was sufficient to determine the necessity for endovascular intervention.

RESULTS

Of the 101 patients referred for carotid intervention, 36 (36%) were shown to have <70% stenoses and did not require intervention. Of those who had significant disease, 49 (75%) underwent successful CAS, 15 (23%) underwent CEA, and 1 patient was treated medically for a total occlusion. Three of the 36 patients not requiring carotid intervention were found to have subclavian stenosis. Two (4%) of the patients undergoing CAS and 4 (27%) of the patients undergoing CEA had minor complications. No patients suffered a major stroke, MI, or death at follow-up.

CONCLUSION

This analysis demonstrates that 36% of patients referred for endovascular intervention based on noninvasive imaging did not meet criteria by angiography. This emphasizes the need for carotid angiography prior to carotid intervention.

Extracranial stenosis: endovascular treatment

Stroke is the third-leading cause of death in the United States. It occurs in almost 700,000 people per year and cost an estimated US dollars 57.9 billion in 2006. Atherosclerotic disease is the cause of one third of these strokes, with more than one half of these stenoses being extracranial in location. Carotid stenoses are usually unifocal and 90% occur within 2 cm of the carotid bulb. Currently, carotid endarterectomy accounts for 117,000 surgical revascularizations per year, whereas carotid angioplasty and stenting are performed less than 10,000 times annually. Stenoses amenable to revascularization are the topic of this article.

An uncommon case of spontaneous resolution of mural thrombus causing symptomatic severe stenosis of the extracranial part of the internal carotid artery

OBJECTIVES

Etiology of ischemic stroke(IS) remains sometimes unexplained in younger subjects. Its well-known causes are atherosclerosis(AS), embolization, arterial dissection, congenital defects, vasculitides, smoking, use of oral contraceptives, coagulopathy and arterial dissection, or vasospasm.

CASE REPORT

A 54-year old male subject was examined because of motor disturbance in his left upper extremity. Computerized tomography(CT) of the brain did not detect any focal pathological changes. Utrasonographic(USG) examination revealed severe stenosis of the right internal carotid artery(ICA) caused by hypoechogenic material, the blood velocity beyond the stenosis was 240 cm/s. The USG finding was confirmed by digital subtraction angiography (DSA). Based on the results of these examinations, an acute carotid endarterectomy (CEA) was indicated. During CEA the vascular surgeon observed patency of the ICA with only small calcified AS plaque on its posterior side. Ultrasonographic examination, performed on the 5(th) day, showed a small calcified AS plaque on the posterior side of the right ICA.

CONCLUSION

In conclusion, if we exclude the possibility of a false positivity of 2 imaging methods at once, we have encountered a very unusual case of SR of stenosing material in the extracranial part of the ICA, initially causing its severe stenosis manifesting by acute neurological symptomatology. The mechanism of this SR remains unclear and the problem should be further studied, preferably using less invasive AG methods.

Complete occlusion of extracranial internal carotid artery: clinical features, pathophysiology, diagnosis and management

A complete occlusion of the internal carotid artery (ICA) is an important cause of cerebrovascular disease. A never-symptomatic ICA occlusion has a relatively benign course, whereas symptomatic occlusion increases future risk of strokes. Ultrasonography, magnetic resonance imaging and contrast angiography are useful diagnostic tests, and functional imaging of the brain (eg, with positron emission tomography) helps to understand haemodynamic factors involved in the pathophysiology of brain ischaemia. Recently, there has been a resurgence of interest in the role of extracranial-intracranial bypass surgery for the treatment of completely occluded ICA. With advances in the measurement of cerebral haemodynamics, it may be possible to identify high-risk patients who could benefit from the bypass surgery.

Anatomically specific clinical examination of the carotid arterial tree

Clinical examination of the carotid arterial system has traditionally been used as a non-specific screening tool of atherosclerotic pathology. Because it has not yet been shown to delineate the precise location and grade of stenosis, further imaging modalities, such as duplex ultrasound, digital subtraction angiography, computed tomography and magnetic resonance, are currently used to obtain this information. These, however, have been shown to be susceptible to inaccuracies. Herein, a new protocol for bedside clinical examination that may define anatomical locality and degree of disease is presented. This consists of palpating the carotid pulse and auscultating for bruits along the course of the common carotid, internal carotid and external carotid arteries, as defined by surface anatomical landmarks from the lower neck to the pharynx. This protocol is not to replace more conventional methods of disease assessment but, in an era of diminishing clinical skills, may add to the overall evaluation of the pathological carotid tree.

Grading of Internal Carotid Artery Stenosis:Comparative Analysis of Different Flow Velocity Criteria and Multidetector Computed Tomographic Angiography

PURPOSE

To evaluate multidetector computed tomographic angiography (CTA) versus published color Doppler sonography (CDS) velocity criteria in the grading of internal carotid artery (ICA) stenosis.

METHODS

Sixty-eight consecutive patients (50 men; mean age 70.2 +/- 8.1 years, range 51- 85) with known ICA stenosis and complete CTA and CDS data for 127 carotid arteries were enrolled in this retrospective analysis. The degree of stenosis was determined using CDS velocities according to 5 published sets of criteria, as well as the criteria used at the authors' institution. These outcomes were then correlated using kappa-statistics with the results of multidetector CTA according to NASCET.

RESULTS

The best overall agreement was achieved applying the criteria sets of Hwang (kappa = 0.70) and AbuRahma (kappa = 0.68). All 5 occlusions were correctly identified with both modalities. CTA detected 73 ICA stenoses > 70%; the best correlation was with the application of Hwang criteria, which correctly identified 69 (94.5%) > 70% stenoses. In order of increasing tendency to underscore the grade of stenosis, the corresponding results for the other criteria sets were 62 (84.9%) for Mittl, 59 (80.8%) for AbuRahma, 55 (75.3%) each for Nicolaides and Filis, and 50 (68.5%) for Nederkoorn. CTA detected 85 stenoses >50%; the sensitivity of all applied CDS criteria sets exceeded 90%.

CONCLUSION

Grading of ICA stenosis > 70% with CDS and CTA results in clinically relevant discrepancies, with higher grades of stenoses assessed by CTA. The choice of CDS grading criteria is of significant clinical importance, especially in the identification of high-grade ICA stenosis.

The reliability of ultrasound measurements of carotid stenosis compared to MRA and DSA

OBJECTIVE

Carotid ultrasound (US) is a screening test for patients with transient ischemic attacks (TIAs) or stroke who then undergo Digital Subtraction Angiogram (DSA) or Magnetic Resonance Angiography (MRA). Gold standard DSA is invasive with inherent risks and costs. MRA is an evolving technology. This study compares reliability of MRA and US modes with DSA in determining degree of internal carotid artery stenosis.

METHODS

A five year retrospective analysis of 140 carotid arteries from patients who had carotid US and DSA, and possibly Magnetic Resonance Angiography was undertaken. Recorded US parameters were peak systolic velocity (PSV), end diastolic velocity (EDV), and ICA/CCA peak systolic velocity ratio. The MRA and DSA parameters used NASCET technique for measuring stenosis. Statistical analysis included ROC curves and Kappa computation.

RESULTS

US grading of carotid stenosis can be made more reliable by choosing appropriate parameters. The best combination of sensitivity and specificity for stenosis > 70% in our hospital was seen at PSV > 173 cm/s (sensitivity 0.87, specificity 0.8, Positive Predictive Value (PPV) 0.70, Negative Predictive Value (NPV) 0.93, kappa 0.64 and weighted kappa 0.71). MRA kappa was 0.78, (sensitivity 0.75, specificity 1.0, PPV 1.0, NPV 0.85).

CONCLUSIONS

US parameters should be validated in each centre. At best, US can only approximate the accuracy of DSA, probably due to inherent limitations of this modality. Magnetic Resonance Angiography has a perfect specificity and PPV but this technique needs to be standardized. Simultaneous use of MRA and US for screening increases sensitivity to over 0.9 without compromising specificity in > 70% stenosis.

Safety of Arch Aortography for Assessment of Carotid Arteries

PURPOSE

To retrospectively review the safety of arch aortography and compare complication rates with published figures for selective catheter angiography.

METHODS

The medical records of patients undergoing arch aortography over the last 3 years (n=311; 180 male, 131 female; mean+/-SD age 71.0+/-9.2 years, range 42-90 years) were retrospectively reviewed. Any peri-procedural (0-48 h) complications were recorded. A certified neurologist (MSR/GSV) classified all questionable neurological events.

RESULTS

There were no focal neurological events or deaths (n=0; 0%; CI: 0-0.96%). Non-focal neurological events included mild disorientation (n=2; 0.6%; CI: 0.176-2.31) and unequal pupils (n=1; 0.3%; CI: 0.056-1.79%). Cardiovascular events included symptomatic hypotension (n=4; 1.3%; CI: 0.50-3.25%), angina (n=1; 0.3%; CI: 0.056-1.79%) and arrhythmia (n=4; 1.3%; CI: 0.50-3.25). There were 27 minor access site complications (8.7%; CI: 6.0-12.3). None of these complications extended hospital stay. None of the arch angiograms had to be followed by selective carotid angiography.

CONCLUSION

Arch aortography appears to have a lower neurological complication rate than selective carotid angiography.