RESUMO
Intima-media thickness (IMT) provides a surrogate end point of cardiovascular outcomes in clinical trials evaluating the efficacy of cardiovascular risk factor modification. Carotid artery plaque further adds to the cardiovascular risk assessment. It is defined as a focal structure that encroaches into the arterial lumen of at least 0.5 mm or 50% of the surrounding IMT value or demonstrates a thickness >1.5 mm as measured from the media-adventitia interface to the intima-lumen interface. The scientific basis for use of IMT in clinical trials and practice includes ultrasound physics, technical and disease-related principles as well as best practice on the performance, interpretation and documentation of study results. Comparison of IMT results obtained from epidemiological and interventional studies around the world relies on harmonization on approaches to carotid image acquisition and analysis. This updated consensus document delineates further criteria to distinguish early atherosclerotic plaque formation from thickening of IMT. Standardized methods will foster homogenous data collection and analysis, improve the power of randomized clinical trials incorporating IMT and plaque measurements and facilitate the merging of large databases for meta-analyses. IMT results are applied to individual patients as an integrated assessment of cardiovascular risk factors. However, this document recommends against serial monitoring in individual patients.
Assuntos
Artérias Carótidas/patologia , Espessura Intima-Media Carotídea , Acidente Vascular Cerebral/patologia , Doenças Cardiovasculares/diagnóstico por imagem , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/patologia , Artérias Carótidas/diagnóstico por imagem , Humanos , Placa Aterosclerótica/diagnóstico , Placa Aterosclerótica/diagnóstico por imagem , Ensaios Clínicos Controlados Aleatórios como Assunto , Medição de Risco , Fatores de Risco , Acidente Vascular Cerebral/diagnóstico por imagemRESUMO
Focused ultrasound-induced opening of the blood-brain barrier (BBB) in the presence of ultrasound contrast agents is a promising strategy for a targeted drug delivery to the brain. The aim of our study was to identify whether brain molecular stress pathways are targeted by ultrasound treatment. Using an upper level of acoustic pressures in combination with microbubbles, which have been previously reported as reliable for BBB opening without causing tissue damage, we found that ultrasound leads to an increased ubiquitinylation of proteins in neuronal (11+/-3 ubiquitin-overexpressing cells per optical field) but not glial cells 6 h post-insonation, increasing to 16 (+/-4) labelled cells after 24 h. No changes in the expression of Hsp70 and Hsc70 were detected over 24 h. Ultrasound treatment was followed by limited apoptosis after 24 h (32+/-6 cleaved-caspase 3-positive cells per optical field) in the insonated areas. Only neurons were identified in the apoptotic population. Although these observations may not be applicable for all acoustic parameters useful for BBB opening, they demonstrate that insonation of the rat brain with the parameters used in our experiments is a useful tool for BBB opening and induces specific cellular stress response restricted to neuronal cells.
Assuntos
Barreira Hematoencefálica/fisiologia , Encéfalo/metabolismo , Neuroglia/metabolismo , Neurônios/metabolismo , Sonicação , Ubiquitina/biossíntese , Animais , Apoptose , Encéfalo/citologia , Sistemas de Liberação de Medicamentos , Regulação da Expressão Gênica , Proteínas de Choque Térmico HSC70/biossíntese , Proteínas de Choque Térmico HSC70/genética , Proteínas de Choque Térmico HSP70/biossíntese , Proteínas de Choque Térmico HSP70/genética , Imageamento Tridimensional , Masculino , Microbolhas , Microscopia Confocal , Proteínas do Tecido Nervoso/biossíntese , Proteínas do Tecido Nervoso/genética , Ratos , Ratos Wistar , Fatores de TempoRESUMO
Combined 2-MHz ultrasound (US) and second-generation, sulfur hexafluoride microbubbles (MB) treatment (US+MB) was performed in a permanent middle cerebral artery (MCA) occlusion model in rats to evaluate possible effects on the ischemic cascade. We used 16 Wistar rats and the MCA occlusion model for stroke induction. Glutamate, pyruvate, lactate and glycerol levels were measured by intracerebral microdialysis before and after stroke induction and after US+MB application (n = 8) for 20 h. After 24 h, brain infarct volume, apoptosis and IL-6 and TNF-alpha levels were evaluated. The infarct volume was significantly reduced (p < 0.05) in the US+MB-treated group compared with control animals. In additional, glutamate levels were significantly lower in US+MB-treated animals, and these animals showed a higher rate of apoptotic cell death in the infarcted area. The levels of IL-6 and TNF-alpha concentrations were not different in both groups, and there was no apoptotic cell death outside the infarction in animals treated with US+MB. The results demonstrate that US+MB with second generation microbubbles does not have a harmful effect on ischemic stroke in an MCA occlusion model of the rat.
Assuntos
Isquemia Encefálica/terapia , Artéria Cerebral Média/diagnóstico por imagem , Terapia Trombolítica/métodos , Animais , Biomarcadores/sangue , Isquemia Encefálica/sangue , Isquemia Encefálica/diagnóstico por imagem , Ácido Glutâmico/sangue , Glicerol/sangue , Infarto da Artéria Cerebral Média/sangue , Infarto da Artéria Cerebral Média/diagnóstico por imagem , Infarto da Artéria Cerebral Média/terapia , Ácido Láctico/sangue , Masculino , Microbolhas , Microdiálise , Modelos Animais , Ácido Pirúvico/sangue , Ratos , Ratos Wistar , Hexafluoreto de Enxofre , UltrassonografiaAssuntos
Meios de Contraste , Ultrassonografia/normas , Europa (Continente) , Humanos , Aumento da Imagem/normas , Nefropatias/diagnóstico por imagem , Neoplasias Renais/diagnóstico por imagem , Hepatopatias/diagnóstico por imagem , Neoplasias/diagnóstico por imagem , Pancreatopatias/diagnóstico por imagemRESUMO
Intima-media thickness (IMT) is increasingly used as a surrogate end point of vascular outcomes in clinical trials aimed at determining the success of interventions that lower risk factors for atherosclerosis and associated diseases (stroke, myocardial infarction and peripheral artery diseases). The necessity to promote further criteria to distinguish early atherosclerotic plaque formation from thickening of IMT and to standardize IMT measurements is expressed through this updated consensus. Plaque is defined as a focal structure that encroaches into the arterial lumen of at least 0.5 mm or 50% of the surrounding IMT value or demonstrates a thickness >1.5 mm as measured from the media-adventitia interface to the intima-lumen interface. Standard use of IMT measurements is based on physics, technical and disease-related principles as well as agreements on how to perform, interpret and document study results. Harmonization of carotid image acquisition and analysis is needed for the comparison of the IMT results obtained from epidemiological and interventional studies around the world. The consensus concludes that there is no need to 'treat IMT values' nor to monitor IMT values in individual patients apart from exceptions named, which emphasize that inside randomized clinical trials should be performed. Although IMT has been suggested to represent an important risk marker, according to the current evidence it does not fulfill the characteristics of an accepted risk factor. Standardized methods recommended in this consensus statement will foster homogenous data collection and analysis. This will help to improve the power of randomized clinical trials incorporating IMT measurements and to facilitate the merging of large databases for meta-analyses.
Assuntos
Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/diagnóstico por imagem , Túnica Íntima/diagnóstico por imagem , Túnica Média/diagnóstico por imagem , Adulto , Idoso , Doenças Cardiovasculares/etiologia , Doenças das Artérias Carótidas/complicações , Ensaios Clínicos como Assunto/métodos , Humanos , Interpretação de Imagem Assistida por Computador , Pessoa de Meia-Idade , Projetos de Pesquisa , Fatores de Risco , Ultrassonografia/métodos , Ultrassonografia/normasRESUMO
OBJECTIVE: The aim of this study was to evaluate number and kind of neurological patients in comparison with other patients on a medical ICU. METHODS: Over a period of one year, all neurological intensive care patients on a medical ICU were evaluated according to age, sex, diagnosis, mortality, diagnostic methods, ventilation and referral to other hospitals and general wards. RESULTS: Comparable to a specialist neurological ICU a wide spectrum of neurological diseases could be observed on an interdisciplinary ICU. In comparison to other patient groups, patients with neurological disease had a higher rate of ventilation, a longer hospital stay and a higher mortality. CONCLUSION: Our data also demonstrate the relevant amount of neurological patients (19 % measured by bed assignment) in comparison to all patients, and the specific neurological procedures were applicable on a medical/interdisciplinary ICU. A higher interest for neurological patient on a medical ICU would therefore be essential.
Assuntos
Unidades de Terapia Intensiva/estatística & dados numéricos , Doenças do Sistema Nervoso/epidemiologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Doenças do Sistema Nervoso/fisiopatologia , Doenças do Sistema Nervoso/terapia , Encaminhamento e Consulta , Respiração Artificial , Mecânica Respiratória/fisiologia , Estudos RetrospectivosRESUMO
PURPOSE: Correlation of duplex ultrasonographic grading of unilateral internal carotid artery (ICA) stenosis and ICA blood volume flow (BVF) quantification. MATERIALS AND METHODS: Using a 2D cine phase-contrast MR technique, 62 patients with unilateral ICA stenosis at the level of the bifurcation between 50 % and 98 % and 20 age-matched normal controls were examined. BVF was measured in the stenosed ICA. Ultrasonographic grading of stenoses was based on cross-sectional duplex sonography (color Doppler flow imaging [CDFI], real-time compound imaging) and compared to the changes in BVF in the stenosed ICA. RESULTS: There was no statistically significant difference in BVF in stenoses of the ICA up to 70 % and in normal controls. ICA stenoses greater 70 % began to be hemodynamically relevant. With increasing stenosis, a decrease in BVF in the ipsilateral ICA was determined with a high and linear correlation of r = - 0.83. Normal controls showed a BVF in an ICA of 247.0 +/- 32.0 ml/min, patients with 70 % stenosis a mean BVF of 225.3 +/- 32.2 ml/min (P = 0.4) without significant reduction, patients with 80 % stenosis a significant reduction of BVF to a mean flow of 184.0 +/- 53.8 ml/min (P < 0.005), patients with 90 % stenosis a reduction of the mean BVF in the stenosed ICA to 84.6 +/- 41.9 ml/min (P < 0.0005) and patients with stenoses > 95 % a mean BVF of only 26.0 +/- 4.0 ml/min (P < 0.0005). In patients with unilateral ICA stenosis greater than 81 %, a significant decrease of BVF in the stenosed ICA was documented. CONCLUSION: Comparison of ultrasonographic grading of unilateral ICA stenosis and BVF determination in patients with ICA stenoses demonstrate a high correlation between increase in the stenosis and decrease in the ipsilateral blood flow beginning at 70 % stenosis. ICA stenoses greater than 80 % are significantly hemodynamically relevant.
Assuntos
Anatomia Transversal/métodos , Volume Sanguíneo , Estenose das Carótidas/diagnóstico , Estenose das Carótidas/fisiopatologia , Imagem Cinética por Ressonância Magnética/métodos , Ultrassonografia Doppler em Cores/métodos , Idoso , Idoso de 80 Anos ou mais , Velocidade do Fluxo Sanguíneo , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Estatística como AssuntoRESUMO
Moyamoya disease is generally recognized in young children. One potential treatment is direct extra-intracranial bypass combined with indirect revascularization using encephalo-myo-synangiosis. Standard follow-up to assess neoangiogenesis includes repeat cerebral angiography, which is invasive. The authors studied whether noninvasive power Doppler imaging could evaluate the patency of the bypass and the degree of indirect revascularization. They found that transcranial power Doppler imaging is a valid noninvasive alternative to cerebral angiography.
Assuntos
Revascularização Cerebral , Circulação Cerebrovascular , Doença de Moyamoya/cirurgia , Neovascularização Fisiológica , Ultrassonografia Doppler Transcraniana/métodos , Criança , Pré-Escolar , Craniotomia , Feminino , Humanos , Lactente , Masculino , Doença de Moyamoya/patologia , Doença de Moyamoya/fisiopatologia , CicatrizaçãoRESUMO
Intima-media thickness (IMT) is increasingly used in clinical trials as a surrogate end point for determining the success of interventions that lower risk factors for atherosclerosis. The necessity for unified criteria to distinguish early atherosclerotic plaque formation from thickening of IMT and to standardize IMT measurements is addressed in this consensus statement. Plaque is defined as a focal structure that encroaches into the arterial lumen of at least 0.5 mm or 50% of the surrounding IMT value or demonstrates a thickness of > or =1.5 mm as measured from the media-adventitia interface to the intima-lumen interface. Standard use of IMT measurements is recommended in all epidemiological and interventional trials dealing with vascular diseases to improve characterization of the population investigated. The consensus concludes that there is no need to 'treat IMT values' nor to monitor IMT values in individual patients apart from few exceptions. Although IMT has been suggested to represent an important risk marker, it does not fulfill the characteristics of an accepted risk factor. Standardized methods recommended in this consensus statement will foster homogenous data collection and analysis. This will help to improve the power of studies incorporating IMT measurements and to facilitate the merging of large databases for meta-analyses.
Assuntos
Artérias Carótidas/diagnóstico por imagem , Túnica Íntima/diagnóstico por imagem , Túnica Média/diagnóstico por imagem , Ultrassonografia/normas , Arteriosclerose/diagnóstico por imagem , HumanosAssuntos
Artérias Cerebrais/diagnóstico por imagem , Embolia Intracraniana/diagnóstico por imagem , Acidente Vascular Cerebral/diagnóstico por imagem , Ultrassonografia Doppler Transcraniana/métodos , Ultrassonografia Doppler Transcraniana/tendências , Causalidade , Artérias Cerebrais/fisiopatologia , Circulação Cerebrovascular/fisiologia , Humanos , Embolia Intracraniana/prevenção & controle , Seleção de Pacientes , Valor Preditivo dos Testes , Fatores de RiscoAssuntos
Estenose das Carótidas/diagnóstico , Angiografia por Ressonância Magnética , Imageamento por Ressonância Magnética , Ultrassonografia Doppler , Estenose das Carótidas/complicações , Feminino , Humanos , Ataque Isquêmico Transitório/etiologia , Angiografia por Ressonância Magnética/métodos , Pessoa de Meia-IdadeRESUMO
We report a traumatic pseudoaneurysm of the internal carotid artery bifurcation and subclavian artery with recurrent strokes events in a 19-year-old man. He was admitted with an acute left hemiparesis. His history revealed a similar episode 1 year and a major car accident 3 years previously. Contrast enhanced MR angiography confirmed colour Doppler sonographic findings of a carotid and subclavian artery pseudoaneurysm presumably resulting from seat-belt trauma. The pseudoaneurysm, containing thrombus, was thought to be the source of artery-to-artery embolism.
Assuntos
Falso Aneurisma/complicações , Doenças das Artérias Carótidas/complicações , Lesões das Artérias Carótidas/complicações , Artéria Carótida Interna , Cintos de Segurança/efeitos adversos , Acidente Vascular Cerebral/etiologia , Artéria Subclávia/lesões , Acidentes de Trânsito , Adulto , Falso Aneurisma/diagnóstico , Falso Aneurisma/etiologia , Doenças das Artérias Carótidas/diagnóstico , Doenças das Artérias Carótidas/etiologia , Lesões das Artérias Carótidas/diagnóstico , Angiografia Cerebral , Humanos , Angiografia por Ressonância Magnética , Masculino , Recidiva , Fatores de Tempo , Ultrassonografia Doppler TranscranianaRESUMO
Ultrasonographic imaging of the carotid arteries allows assessment of both early and advanced atherosclerotic disease. This noninvasive technique has played a central role in many recent epidemiological studies and is being used increasingly for evaluating the efficacy of atherosclerosis prevention trials. New developments in ultrasound equipment, the use of echocontrast agents, novel applications of three- and four-dimensional sonography and in vivo characterization of plaque constituents with high-resolution MRI have broadened the scope of imaging of arterial walls, providing both enhanced information on disease progression as well as new insights into pathomechanisms of carotid plaque embolization. This article highlights pertinent issues of imaging of arterial wall disease and discusses important areas of current and future research in this field.
Assuntos
Artérias , Imageamento por Ressonância Magnética , Doenças Vasculares/diagnóstico por imagem , Doenças Vasculares/diagnóstico , Arteriosclerose/diagnóstico , Arteriosclerose/diagnóstico por imagem , Humanos , Túnica Íntima/diagnóstico por imagem , Túnica Íntima/patologia , Túnica Média/diagnóstico por imagem , Túnica Média/patologia , UltrassonografiaAssuntos
Afasia/diagnóstico , Hemiplegia/diagnóstico , Artes Marciais/lesões , Doença Aguda , Adulto , Afasia/etiologia , Braço/fisiopatologia , Dissecação da Artéria Carótida Interna/diagnóstico , Estenose das Carótidas/complicações , Estenose das Carótidas/diagnóstico por imagem , Diagnóstico Diferencial , Hemiplegia/etiologia , Humanos , Infarto da Artéria Cerebral Média/diagnóstico , Infarto da Artéria Cerebral Média/etiologia , Infarto da Artéria Cerebral Média/terapia , Imageamento por Ressonância Magnética , Masculino , Terapia Trombolítica , UltrassonografiaRESUMO
Although recent studies have demonstrated the potential value of compounded data for improvement in signal-to-noise ratio and speckle contrast for three-dimensional (3-D) ultrasonography, clinical applications are lacking. We investigated the potential of six degrees-of-freedom (6-DOF) scanhead position and orientation measurement (POM) devices for registration of in vivo multiplanar, irregularly sampled ultrasound (US) images to a regular 3-D volume space. The results demonstrate that accurate spatial and temporal registration of four-dimensional (4-D) US data can be achieved using a 6-DOF scanhead tracking system. For reconstruction of arbitrary, irregularly sampled US data, we introduce a technique based upon a weighted, ellipsoid Gaussian convolution kernel. Volume renderings of 3-D and 4-D compounded in vivo US data are presented. The results, although restricted to the field of cerebrovascular disease, will be of value to other applications of 3-D sonography, particularly those in which compounding of data through irregular sampling may provide superior information on tissue or vessel structure.
Assuntos
Artérias Carótidas/diagnóstico por imagem , Artérias Cerebrais/diagnóstico por imagem , Transtornos Cerebrovasculares/fisiopatologia , Processamento de Imagem Assistida por Computador , Ultrassonografia Doppler Transcraniana , Velocidade do Fluxo Sanguíneo , Artérias Carótidas/fisiopatologia , Artérias Cerebrais/fisiopatologia , Circulação Cerebrovascular , Transtornos Cerebrovasculares/diagnóstico por imagem , Humanos , Reprodutibilidade dos Testes , Ultrassonografia Doppler em CoresRESUMO
Pulse-inversion contrast harmonic imaging is a new ultrasonographic technique that can assess brain perfusion. In an adult with moyamoya disease and multiple recurrent strokes, this method detected subtle hemispheric differences in temporal-lobe perfusion, presumably due to neovascularisation, which were not shown by xenon-computed tomography or magnetic resonance perfusion imaging.
Assuntos
Doença de Moyamoya/diagnóstico por imagem , Ultrassonografia Doppler de Pulso/métodos , Adulto , Encéfalo/irrigação sanguínea , Meios de Contraste , Ecoencefalografia/métodos , Feminino , Humanos , Doença de Moyamoya/patologia , PolissacarídeosRESUMO
BACKGROUND AND PURPOSE: In vitro studies of atherosclerotic plaque fracture mechanics suggest that analysis of local variations in surface deformability may provide information on relative vulnerability to plaque fissuring or rupture. We investigated plaque surface deformations in patients with symptomatic and asymptomatic carotid artery disease using 4-dimensional ultrasonography and techniques for measuring optical flow. METHODS: Four-dimensional ultrasound examinations of carotid artery plaques were performed in 23 asymptomatic and 22 symptomatic patients with 50% to 90% stenosis of the internal carotid artery. Plaque surface motion during 1 cardiac cycle was computed with a hierarchical model-based motion estimator. Results were compared with plaque echogenicity and surface structure. RESULTS: Of the 45 patients examined, plaque surface motion estimates were obtained for 18 asymptomatic and 13 symptomatic patients. There were no significant differences in echogenicity or surface structure of asymptomatic and symptomatic plaques (P>0.05). Results of motion estimation showed that asymptomatic plaques had surface motion vectors of equal orientation and magnitude to those of the internal carotid artery, whereas symptomatic plaques demonstrated evidence of inherent plaque movement. There was no significant difference in maximal plaque velocity between symptomatic and asymptomatic plaques (P<0.14). Maximal discrepant surface velocity (MDSV) in symptomatic plaques was 3.85+/-1.26 mm/s (mean+/-SD), which was significantly higher (P<0.001) than MDSV of asymptomatic plaques with 0.58+/-0.42 mm/s (mean+/-SD). CONCLUSIONS: ++MDSV of carotid artery plaques is significantly different in asymptomatic and symptomatic disease. Further studies are warranted to determine whether plaque surface motion patterns can identify vulnerable plaques in patients with carotid artery stenosis.
Assuntos
Artéria Carótida Interna/diagnóstico por imagem , Estenose das Carótidas/diagnóstico por imagem , Idoso , Estenose das Carótidas/fisiopatologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Movimento (Física) , UltrassonografiaRESUMO
Rapid progress in noninvasive ultrasound techniques has resulted in a wide variety of clinical applications for assessment of both extracranial and intracranial arterial diseases. Recent highlights in cerebrovascular ultrasound research include imaging methods for characterization of intracranial aneurysms, use of echocontrast agents for improved evaluation of acute stroke patients and transient response harmonic imaging for depiction of brain perfusion. The important role of transcranial Doppler microembolism detection in carotid endarterectomy has been defined, new approaches to noninvasive Doppler measurement of intracranial pressure are progressing, and the clinical indications for transcranial Doppler monitoring of intracranial vasospasm to prevent secondary stroke have expanded. New functional transcranial Doppler applications, which are complementary to positron emission tomography and functional magnetic resonance imaging studies, are evolving for evaluation of functional recovery after stroke; investigation of perfusion asymmetries during complex spatial tasks; assessment of hemispheric dominance in surgical candidates for epilepsy surgery; and elucidation of temporal patterns of regional neuronal activity. With increasing sophistication of cerebrovascular ultrasound methodology, it is essential that standards for data acquisition and interpretation be established. Three recent consensus meetings have provided detailed recommendations on quantification of carotid artery stenosis, on characterization of carotid artery plaques and on microembolism detection by transcranial Doppler.
Assuntos
Transtornos Cerebrovasculares/diagnóstico por imagem , Humanos , UltrassonografiaRESUMO
Although little is known on the pathophysiologic mechanism of migraine-related stroke, the prevailing attitude is that vasoconstriction and activation of clotting factors play a primary role. In 2 female patients presenting with migraine and stroke, risk profiles and history were consistent with this pathophysiologic mechanism. Cerebro- and cardiovascular workup, however, led to a diagnosis of paradoxical cardioembolic stroke through a patent foramen ovale. Since there is hardly any evidence in the literature that migraine acts as a risk factor for stroke on its own, these case reports emphasize the importance of complete cardiovascular evaluation in patients with suspected migrainous stroke.