Degree Of Artery Stenosis Research Articles

Analysis of carotid artery of patients with acute ischemic stroke by dual-source computed tomographic angiography

To investigate the changes on carotid artery of patients with acute ischemic stroke by dual source computed tomographic angiography (DS-CTA) . From March 2009 to August 2010, 71 patients with acute ischemic stroke (IS group) underwent magnetic resonance imaging, which showed high signals on diffusion-weighted images. The location of atherosclerotic plaques in carotid artery, the nature of plaques, and the grade of stenosis were analyzed by DS-CTA, and the results were further compared with 45 patients with non-ischemic stroke (control group) . In the IS group, 196 atherosclerotic plaques in the carotid artery were detected in 51 patients; the commonest locations included carotid artery bifurcation (52.0%) and trunk (20.4%) . Most plaques were combined plaques [52.0% (102/196) ] and soft plaques [27.0% (53/196) ] . Moderate and severe stenosis accounted for 86.3% in these 54 patients. The positive rate, nature, and location of plaques and the stenosis degree of artery were significantly different between IS group and control group (allP<0.05) . The commonest plaques in the carotid artery of patients with acute ischemic stroke are combined plaques and soft plaques, which often cause moderate and severe stenosis.

P200 Snoring and carotid atheroma: no association

BackgroundObstructive Sleep apnoea (OSA) has increasingly been linked to cardiovascular endpoints including hypertension, stroke, myocardial infarction, and carotid atherosclerosis. Snoring is strongly associated with OSA. More recently, the snoring component...

Correlation between the Degree of Left Subclavian Artery Stenosis and the Left Vertebral Artery Waveform by Pulse Doppler Ultrasonography

Background:Development of retrograde blood flow may be observed in the vertebral artery and is associated with progressive ipsilateral proximal subclavian or innominate artery stenosis. The subclavian steal phenomenon is more prevalent in the left subclavian artery (LSA). The purpose of this study was to analyze the correlation between the degree of LSA stenosis and pulse Doppler waveforms of the left vertebral artery (LVA). Methods:A retrospective analysis of LVA waveforms was performed in 22 cases with LSA proximal stenosis before the origin of the LVA in conventional angiograms. The degree of LSA stenosis was classified into 5 groups (<50, 50–59, 60–69, 70–89, 90–100%). Pulse Doppler waveforms of the LVA were also classified into 5 subtypes depending on the depth of the mid-systolic notch representing retrograde blood flow (normal, mid-systolic notch, retrograde flow smaller than antegrade flow, retrograde flow larger than antegrade flow, retrograde flow without antegrade flow). Results:A statistically significant correlation (R² = 0.646, p < 0.0001) was found between the degree of LSA stenosis and the LVA waveform. Conclusions:The pattern analysis of LVA pulse Doppler waveforms seems to be useful in determining the degree of LSA stenosis.

A New Computerized Measurement Approach of Carotid Artery Stenosis on Tomographic Image Sequence

The stenosis degree of carotid artery (CA) can be a critical factor for treatment of cerebrovascular disease and for determining candidate of carotid endarterectomy. Currently, three different measuring methods are applied only on projectional cervical images. These measurement methods introduce several demerits such as a thromboembolic event, and three reference positions provide the different measurement results even on same subject. In addition, projection image could not provide the most severe stenosis position by nature; and the manual measurements also provide the inter-observer and intra-observer variability. Therefore, a computerized measuring scheme is necessary to overcome these drawbacks. By applying local adaptive thresholding technique on cervical magnetic resonance angiogram image sequence, CA objects are initially identified. These are used to determine the three-dimensional central axis of CA by using circumscribed quadrangle. The oblique slices are reformatted into two-dimensional image planes, which are perpendicular to the central axis of CA, to provide the circular shape of blood vessel provided that the artery runs horizontally across the scanning axis. After that, region growing technique is applied on obliquely reformatted image sequence followed by geometrically restoration of segmented CA objects. The percentage of stenosis can be defined by the area ratio of segmented CA to restored CA object. The stenosis grading of is [(A-B)/A]×100%, where A represents area measure of restored object, B represents area measure of segmented CA object. Experiments have been conducted on both phantom that simulated the mild (30%), moderate (50%), and severe (70%) stenosis degree for validation of proposed measurement approach and 86 carotid arteries from 43 clinical data sets (including 5 occlusion cases). The automated approach is recommended to measure the carotid stenosis by using axial image sequence. This technique is not only accurate as possible but also robust, simple to handle, and less time consuming as compared to manual measurements. In addition, a computerized carotid stenosis measuring method is necessary to overcome the drawbacks introduced by using the projectional image and measurement variability of inter-observer, intra-observer.

E0464 Clinical significance of the changes of serum TNF-α, IFN-γ, MMP-9

A variety of inflammatory factors in atherosclerosis (AS) plays a complex role, the combination of two or more of the inflammatory mediators can increase inflammatory mediators in coronary heart disease...

Correlation between kinking and coiling of the carotid arteries as assessed using MDCTA with symptoms and degree of stenosis

To evaluate whether the presence of kinking and coiling of the carotid arteries is associated with symptoms and an increased degree of carotid artery stenosis. One hundred and fifty-three consecutive patients examined using multidetector-row computed tomography angiography (MDCTA) were studied retrospectively. The arterial phase was obtained by injecting 4-6ml/s of contrast material. A total of 306 carotid arteries were assessed for the presence of tortuosity. The degree of carotid artery stenosis was measured according to North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria. Logistic regression analysis was performed to determine whether an independent association existed between the presence of vessel tortuosity, symptoms, and the degree of carotid artery stenosis. Kinking was detected on 37 occasions (12.1%) and coiling on 20 occasions (6.5%). Using Yates's corrected chi-square test, an association between kinking and symptoms (p=0.002) was observed, but not between coiling and symptoms (p=0.31). Logistic regression confirmed that the strongest association was present between stenosis degree and symptoms (p=0.001), but kinking (p=0.009) and age (p=0.001) were also significantly associated with symptoms. A Mann-Whitney test did not demonstrate correlation between coiling (p=0.16) or kinking (p=0.22) and increased degree of carotid artery stenosis. The results suggest that kinking may be associated with symptoms, whereas coiling does not appear to be associated with symptoms. The degree of carotid artery stenosis severity is not related to the presence of vessel tortuosity.

Matching pathophysiology and evidence-based medicine for optimal management of ischemic heart disease

In recent years, our understanding of the pathophysiology of ischemic heart disease has evolved greatly. Atherosclerosis, traditionally considered a focal cholesterol storage disease, is now viewed as a widespread inflammatory process, responsible for the development, evolution and complications of arterial lesions. It is now recognized that most atherosclerotic lesions grow outward; thus, a substantial burden of atherosclerosis can exist in the absence of stenosis. Moreover, intravascular ultrasound and autopsy studies have indicated that vulnerable plaques are usually represented by mildly obstructive lesions. In the pathophysiology of ischemic heart disease, particular attention has been focused on endothelial and microvascular function. Structural or functional alterations of coronary microcirculation have been documented in several clinical conditions, such as stable and unstable angina. In this clinical setting, microvascular dysfunction acts not only as an independent risk marker, but can also contribute to the precipitation or maintenance of myocardial ischemia, even in the absence of coronary atherosclerosis. These observations challenge the traditional hemodynamic approach to the treatment of ischemic heart disease based on the degree of arterial stenosis. Isolated revascularization of a coronary artery can relieve angina and ischemia caused by a flow-limiting stenosis, but is often unable to protect against future atherothrombotic events or to modify the natural history of disease. Recent randomized trials have confirmed these pathophysiological findings, revealing no advantage of a routine over a selective invasive strategy in the treatment of stable angina. Global management of ischemic heart disease should aim to combine primary and secondary prevention measures directed at long-term risk reduction, with optimal revascularization therapies.

Difference in Infarct Volume and Patterns between Cardioembolism and Internal Carotid Artery Disease: Focus on the Degree of Cardioembolic Risk and Carotid Stenosis

Background and Objective: Infarct volume and patterns may vary according to the stroke subtype. Within each stroke subtype, however, it is not clear if the infarct volume and patterns are affected by the risk of cardioembolism (CE) and the degree of arterial stenosis. Patients and Methods: We included consecutive patients with acute symptomatic ischemic lesions on diffusion-weighted imaging (DWI) performed within 48 h of symptom onset who had CE or internal carotid artery disease (ICAD). CE was divided into high-risk and medium-risk groups, and ICAD was divided into ICA occlusion (ICAO) and ICA stenosis (ICAS ≧50%) groups. DWI lesion patterns were classified as single versus multiple, and as large territorial versus perforating artery (large ≧2 cm, small <2 cm) versus pial artery versus border zone infarct. Infarct volumes and National Institutes of Health Stroke Scale (NIHSS) scores were obtained. Results: Of the 167 patients included, 120 had CE (98 high-risk, 22 medium-risk) and 47 had ICAD (25 ICAO, 22 ICAS). The infarct volume was largest in the high-risk CE group, followed by the ICAO group. The infarct volumes in the medium-risk CE and ICAS groups were similar. Infarct volumes correlated with NIHSS scores. Single and large territorial infarcts were more common in the high-risk CE group, while multiple lesions as well as pial and border zone infarcts were more frequent in the ICAD subgroups. The lesion patterns of the medium-risk CE and ICAD groups were relatively similar. Conclusions: CE and ICAD have heterogeneous radiologic characteristics depending on the risk of embolism and the degree of carotid stenosis.

Imaging of the Fibrous Cap in Atherosclerotic Carotid Plaque

In the last two decades, a substantial number of articles have been published to provide diagnostic solutions for patients with carotid atherosclerotic disease. These articles have resulted in a shift of opinion regarding the identification of stroke risk in patients with carotid atherosclerotic disease. In the recent past, the degree of carotid artery stenosis was the sole determinant for performing carotid intervention (carotid endarterectomy or carotid stenting) in these patients. We now know that the degree of stenosis is only one marker for future cerebrovascular events. If one wants to determine the risk of these events more accurately, other parameters must be taken into account; among these parameters are plaque composition, presence and state of the fibrous cap (FC), intraplaque haemorrhage, plaque ulceration, and plaque location. In particular, the FC is an important structure for the stability of the plaque, and its rupture is highly associated with a recent history of transient ischaemic attack or stroke. The subject of this review is imaging of the FC.

Preliminary experience with MRA in evaluating the degree of carotid stenosis and plaque morphology using high-resolution sequences after gadofosveset trisodium (Vasovist) administration: comparison with CTA and DSA

The authors performed a preliminary study with blood-pool contrast-enhanced magnetic resonance angiography (MRA) in evaluating the degree of carotid artery stenosis and plaque morphology, comparing the diagnostic performance of first-pass (FP) and steady-state (SS) acquisitions with 64-slice computed tomography angiography (CTA) and using digital subtraction angiography (DSA) as the reference standard. Twenty patients with >or=50% carotid artery stenosis at Doppler sonography underwent blood-pool contrast-enhanced MRA, CTA and DSA. Two independent radiologists evaluated MRA and CTA examinations to assess the degree of stenosis and characterise plaque morphology. Accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for FP, SS and CTA. The McNemar and Wilcoxon tests were used to determine significant differences (p<0.05) between the diagnostic performance of the three modalities. Forty carotid bifurcations were studied. For stenosis grading, accuracy, sensitivity, specificity, PPV and NPV were 90%, 89%, 90%, 89% and 90%, respectively, at FP; 95%, 95%, 95%, 95% and 95%, respectively, at SS; and 97.5%, 95%, 100%, 100% and 95%, respectively, at CTA. SS and CTA were superior to FP for evaluating the degree of stenosis (p<0.05). For evaluating plaque morphology, accuracy, sensitivity, specificity, PPV and NPV were 87.5%, 89%, 86%, 85% and 90%, respectively, at FP; 97.5%, 100%, 95%, 95% and 100%, respectively, at SS; and 100%, 100%, 100%, 100% and 100%, respectively, at CTA. There were no significant differences between FP, SS and CTA for plaque assessment (p>0.05). Blood-pool contrast-enhanced MRA with SS sequences allow improved diagnostic evaluation of the degree of carotid stenosis and plaque morphology compared with FP and is substantially equal to CTA and DSA.

Carotid Artery Stenosis Correlation with Hyperhomocysteinemia in Stroke Patient Group: a Prospective Study

Carotid Artery Stenosis Correlation with Hyperhomocysteinemia in Stroke Patient Group: a Prospective Study Introduction. Stroke is the second most common cause of death worldwide and one of the major causes of long-term disability. Carotid artery stenosis is an independent risk factor for ischemic stroke and related forms of atherosclerotic vascular disease. Aim of the Study was to examine plasma homocysteine (tHcy) levels in the stroke patient's group with significant carotid artery stenosis, to determine hyperhomocysteinemia correlation with degree of carotid artery stenosis. Materials and methods. This study was prospective and all patients (n=102) included in the study were hospitalized in Pauls Stradins Clinical University hospital in Clinic of Neurology with diagnosis of acute ischemic stroke. In the group of significant carotidal stenosis we included 48 patients with various degree of stenosis ranging from 50% to total occlusion. Evaluations of stenosis of extracranial carotid arteries were done by duplex ultrasonography method. The blood of these patients was tested for homocysteine level by ELISA (IMMULITE 2000). Results. Study did not demonstrated statistically significant difference between levels of tHcy in all groups. Mean homocysteine level was not significantly higher in the symptomatic carotid stenosis patient's group. Also there were no significant differences between levels of homocysteine in patient group with different degree of stenosis. Conclusions. We found no meaningful association between a high tHcy level and extent of carotid stenosis.

Prevalence of Asymptomatic Critical Carotid Artery Stenosis in Korean Patients with Chronic Atherosclerotic Lower Extremity Ischemia: Is a Screening Carotid Duplex Ultrasonography Worthwhile?

This study aimed to investigate prevalence of asymptomatic carotid artery stenosis (ACAS) in Korean patients with peripheral arterial disease (PAD) and identify predictive factors of ACAS in patients with PAD. Between 1994 and 2008, 546 patients who underwent bypass surgery due to PAD were identified in a single tertiary teaching hospital. Of those, 409 patients underwent preoperative screening carotid duplex ultrasonography (CDUS). Patients who had an episode of cerebrovascular event or previous carotid artery intervention were excluded and then a retrospective analysis was made of 340 patients. The degree of internal carotid artery (ICA) stenosis was determined by the criteria of Society of Radiologists in Ultrasound Consensus Conference. To determine the risk factors of ACAS, demographic, coexisting medical condition and lesion characteristics were tested with binary logistic regression model. The prevalence of ≥70% ICA stenosis was 14%. ICA occlusion was detected in 7.1%. Multivariate analysis revealed age >65 yr (OR: 2.610, 95% CI: 1.197-5.691) and coronary artery disease (CAD, OR: 2.333, 95% CI: 1.169-4.657) are predictive factors of ≥70% stenosis. A PAD patient who needs revascularization, particularly, >65 yr or has a concomitant CAD, can be a good candidate of screening CDUS.

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

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

Coagulation activation and ultrasound characteristics in patients with carotid artery disease

Introduction Elevated levels of markers for thrombin activation are associated with plaque echogenicity and degree of stenosis in patients with carotid artery stenosis. The Activated Protein C-Protein C Inhibitor (APC-PCI) complex reflects activation of the Protein C system and is a measure of thrombin generation. The aim of the present study was to examine APC-PCI complex in patients undergoing thrombendartherectomy for carotid artery stenosis, and to relate the findings to clinical characteristics and plaque morphology as determined by ultrasound. Materials and Methods Blood was obtained from 125 patients (39 female, median age 71 years) with carotid artery stenosis admitted from September 2005 to May 2007. The APC-PCI complex was measured using a sandwich immunofluorometric method and compared to an age- and sex-matched healthy control-group. Clinical and demographic characteristics, routine laboratory markers and ultrasound characteristics were analysed using univariate and multivariate analysis. Results APC-PCI complex concentration was significantly increased in patients with carotid artery stenosis (median 0.21 µg/L; 10th to 90th percentile 0.15–0.36) compared to a healthy control-group (0.19 µg/L; 0.11–0.31; P = .009). There was no significant difference in APC-PCI-values between asymptomatic (n = 48) and symptomatic (n = 77) patients with carotid artery stenosis (0.22 vs. 0.20 µg/L; p = 0.626). Patients with minor stroke (n = 31) had a higher median APC-PCI-concentration (0.27 µg/L; 0.15–0.63) than patients with amaurosis fugax (0.19 µg/L; 0.15–0.36) or transient ischemic attack (0.21 µg/L; 0.12–0.36) (p = 0.016). No association was found between APC-PCI-values and the degrees of carotid artery stenosis or the time from the latest neurological symptoms to blood sampling. Patients with echolucent plaques had significantly lower APC-PCI concentrations (0.20 µg/L; 0.14–0.35 vs. 0.24 µg/L; 0.15–0.60; p = 0.043), according to the Gray-Weale classification. Conclusions Patients with carotid artery disease exhibit increased concentrations of APC-PCI compared to a healthy control-group, particularly those patients with echogenic plaques, who have significantly higher APC-PCI levels than patients with echolucent plaques.

Overestimation of contralateral internal carotid artery stenosis before ipsilateral surgical endarterectomy

The aim of this study was to investigate a possible overestimation of the degree of contralateral carotid artery stenosis by duplex in patients with significant bilateral carotid stenoses who are to undergo carotid endarterectomy (CEA). A retrospective analysis was performed of all patients undergoing CEA in our center over a period of 11 years. Pre- and postoperative duplex ultrasonography measurements of peak systolic velocity (PSV) and end diastolic velocity (EDV) were compared and used to classify the degree of stenosis. Univariate analysis was performed to indicate possible predictors for contralateral stenosis overestimation. A total of 384 CEA procedures in 357 patients were performed in our hospital. Pre- and postoperative bilateral duplex measurements were available in 135 patients. Forty-four out of 135 patients (33%) were preoperatively identified as having significant stenosis (>60%) of the internal carotid artery on both sides. In these patients, postoperative duplex measurements of the contralateral carotid showed a decrease in mean (SD) PSV from 2.53 (1.11) m s(-1) to 1.97 (0.87) m s(-1) (P<0.01) and a decrease in EDV from 0.87 (0.60) m s(-1) to 0.60 (0.36) m s(-1) (P<0.01). The absolute changes in contralateral PSV and EDV after CEA were larger among patients with a higher degree of stenosis preoperatively. These changes led to reclassification of stenosis to a lesser degree in 24 (55%) patients. In 16 cases (36%), this resulted in a measured stenosis on the contralateral side of less than 60%. One-third of the patients with duplex measurements consistent with bilateral significant carotid stenosis did not have a significant contralateral stenosis by duplex after CEA. Therefore, additional postoperative duplex measurement is advisable before planning contralateral CEA.

Diagnostik zur Graduierung der extrakraniellen Karotisstenose – Verfahren und deren Bedeutung für die Therapieentscheidung

Die Stenose der A. carotis interna ist eine wesentliche Ursache für den ischämischen Schlaganfall. Sie sollte zur Prävention eines Hirninfarktes frühzeitig erkannt werden. Dazu stehen mit der farbkodierten Duplexsonografie, der Angiografie mit Computertomografie (CTA), Magnetresonanztomografie (MRA) und Katheterangiografie (DSA) mehrere Verfahren zur Verfügung. Ihre Bedeutung für die Erkennung einer Stenose und Bestimmung des Stenosegrades wird dargestellt. Die Ultraschalluntersuchung ist die wichtigste Untersuchung, da sie breit verfügbar, leicht wiederholbar und relativ zuverlässig ist. CTA und MRA haben den Vorteil, dass sie die Halsgefäße vom Aortenbogen bis ins Schädelinnere abbilden und so weitere pathologische Gefäßveränderungen aufzeigen können. Vor einer therapeutischen Entscheidung setzen wir eines der beiden Verfahren zusätzlich zur Sonografie ein, wobei die CTA präzisere Angaben erlaubt. Die invasive Angiografie ist wegen des immanenten Risikos und der Belastung des Patienten heute nur noch in Sonderfällen, ansonsten im Zusammenhang mit der endovaskulären Therapie indiziert.

Carotid Artery Diameter, Plaque Morphology, and Hematocrit, in Addition to Percentage Stenosis, Predict Reduced Cerebral Perfusion Pressure during Cardiopulmonary Bypass: A Mathematical Model

Cerebral complications after cardiac surgery are a significant cause of morbidity, mortality, and financial cost. Numerous risk factors have been proposed to explain the risk of cerebral damage. Carotid artery disease has an important role. Percentage carotid artery stenosis is the only measure of carotid artery disease that is used by cardiac surgeons to determine the need for either a carotid endarterectomy and/or a higher pump perfusion pressure. Identification of patients through their carotid plaque morphology who might benefit from higher pump perfusion pressures or concomitant carotid endarterectomy may reduce cerebral morbidity and mortality. A mathematical model using finite element analysis was created to model the carotid artery vessel and its stenotic plaque. Analysis showed that the degree of carotid artery stenosis, the length of the carotid artery plaque, the diameter of the carotid artery, and the blood hematocrit all independently significantly affect the required pump perfusion pressure to main tain adequate cerebral perfusion during cardiopulmonary bypass (CPB). The results from a mathematical model showed that carotid artery dia meter, carotid artery plaque length, and hematocrit, in addition to percentage stenosis, should be included in any thought process involving carotid artery stenosis and cardiac surgery. Estimating cerebral risk during CPB should no longer rely on only the percentage stenosis.

Predictors of shunt during carotid endarterectomy with routine electroencephalography monitoring

The routine use of intraoperative electroencephalography (EEG) monitoring with selective shunt placement during carotid endarterectomy (CEA) has been shown to be safe and effective. We attempt to identify the anatomic and clinical factors associated with significant EEG changes requiring shunt placement during CEA. Between January 2005 and June 2007, 242 CEAs were performed with selective shunt placement for significant EEG changes. Risk factors assessed include severity of both ipsilateral and contralateral disease, presence of ipsilateral preoperative symptoms, hypertension, coronary artery disease, diabetes, age, gender, and preemptive intraoperative blood pressure manipulation to >or=20% above baseline before cross-clamping. Data were analyzed with the chi(2) test (P < .05 was significant). CEA was performed for asymptomatic disease in 177 of 242 patients (73.1%). The perioperative stroke rate was 0.8% (2 of 242), and the overall morbidity rate was 4.5%. No patients died. Significant EEG changes requiring shunt occurred in 35 patients (14.46%). Factors associated with carotid shunt placement were moderate ipsilateral carotid artery stenosis (50% to 79%) compared with severe (>or=80%) disease (30.6% vs 11.7%, P = .003) and degree of contralateral carotid stenosis (0% to 49%, 10.8%; 50% to 79%, 10.9%; 80% to 99%, 23.2%; occlusion, 50%; P = .0003). Presence of symptoms, gender, age, hypertension, diabetes, or coronary artery disease, and preemptive intraoperative manipulation of blood pressure were not significant predictors of shunt placement. CEA performed with routine EEG monitoring and selective shunt placement is associated with a low risk of perioperative stroke. Identified predictors of significant EEG changes were anatomic factors including degree of contralateral carotid artery disease and moderate ipsilateral carotid artery stenosis (50% to 79%). Although contralateral carotid occlusion has been accepted as indication for shunt placement in the absence of cerebral monitoring, this study suggests that high-grade contralateral disease and moderate ipsilateral carotid stenosis are associated with cerebral ischemia resulting in EEG changes and should prompt consideration for nonselective shunting.

Ultra-Fast Carotid CT-Angiography

Noninvasive imaging is increasingly accepted for the evaluation of atherosclerotic disease of the carotid arteries. We sought to evaluate the feasibility of a low-contrast media volume protocol for carotid computed tomography angiography (CTA) using a 128-slice-spiral-computed tomography scanner with a gantry rotation time of 300 milliseconds. Thirty consecutive patients underwent CTA for the evaluation of the carotid vessels, with a 128-section scanner. Fifteen patients were examined with a standard volume contrast injection protocol (group A): 80 mL of contrast material (CM) were injected at 5 mL/s using the test bolus method to assess individual transit time. Another 15 patients were examined with a low-volume contrast media protocol (group B): 30 mL CM were injected at 4 mL/s using bolus tracking to trigger the CTA acquisition. In both groups, contrast administration was followed by a saline flush. Image quality and segmental vascular enhancement as well as the presence and degree of arterial stenosis were independently evaluated by 2 radiologists. Venous enhancement and streak artifacts at the thoracic inlet because of highly concentrated CM in the subclavian veins were evaluated in both groups. Kappa statistic and Pearson correlation coefficient were used to quantify interobserver variability. Qualitative data were compared using the Wilcoxon signed rank test and student t test was used to investigate differences in segmental vessel attenuation. All studies were of diagnostic quality in both groups. Interobserver agreement was high (kappa = 0.82, group A; kappa = 0.78, group B). Attenuation measurement showed excellent interobserver correlation in both groups (r > 0.9). Mean enhancement values were slightly higher in group A, but without statistical significance when averaged for all segments (P = 0.06). Streak artifacts impaired evaluation of 13 adjacent arterial segments in 8 patients at the level of the thoracic inlet in group A. In group B, only 1 segment was rated insufficient by both radiologists. Venous enhancement was significantly lower in group B (P = 0.04). The low-contrast protocol proved to be the more robust method with constant high arterial enhancement, less streak artifacts at the thoracic inlet, and less venous overlay. Using the latest CT technology, optimal depiction of the craniocervical arteries can be archived with a low-volume (30 mL) CM protocol.

Effects of short- and long‑term efficacy of percutaneous transluminal renal angioplasty with or without intravascular brachytherapy on regression of left ventricular hypertrophy in patients with renovascular hypertension

The largest group of patients with secondary hypertension comprises individuals with renovascular hypertension resulting from renal artery stenosis that is a potentially removable condition. It is caused by atherosclerosis in 70-80% of patients. The aim of the study was to evaluate the influence of intravascular brachytherapy (IVBT) procedure performed after percutaneous transluminal renal angioplasty (PTRA) on left ventricular (LV) function, mass regression and type of hypertrophy (LVH) determined on echocardiography during long-term follow-up. Sixty-two patients with atherosclerotic renal artery stenosis complicated by severe hypertension were treated with PTRA and randomly assigned to group 1 (PTRA alone) or group 2 (PTRA followed by IVBT). Subsequent IVBT was performed with the PARIS catheter and the Microselectron HDR (Nucletron) system for peripheral arteries. Treatment outcomes during follow-up were assessed with quantitative coronary angiography. LV mass and mass index (LVM and LVMI) and functional parameters prior to PTRA and during follow-up were determined by echocardiography with regard to the type of procedure. The degree of renal artery stenosis was significantly different in groups 1 and 2. In both groups elevated LVMI was observed (p = 0.94). There were no significant differences in interventricular septum (IVS) to LV posterior wall (LVPW) ratio, relative LV wall thickness, volumetric parameters and LV ejection fraction between both groups. During follow-up the values of LVMI and IVS to LVPW ratio were significantly lower (p = 0.021 and p = 0.004, respectively) in the PTRA + IVBT group compared to the PTRA group. Analysis of the LV geometry and type of hypertrophy revealed a marked reduction in concentric LVH in the IVBT group during long-term follow-up. Echocardiographic evaluation comparing several LV parameters in the PTRA alone and PTRA + IVBT groups showed that PTRA with subsequent brachytherapy were associated with better control of blood pressure and greater LVM regression, especially concentric hypertrophy, during long-term follow-up.