Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 149
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Magn Reson Imaging ; 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38263621

RESUMO

BACKGROUND: Hypertension-induced impairment of the cerebral artery network contributes to cognitive impairment. Characterizing the structure and function of cerebral arteries may facilitate the understanding of hypertension-related pathological mechanisms and lead to the development of new indicators for cognitive impairment. PURPOSE: To investigate the associations between morphological features of the intracranial arteries distal to the circle of Willis on time-of-flight MRA (TOF-MRA) and cognitive performance in a hypertensive cohort. STUDY TYPE: Prospective observational study. POPULATION: 189 hypertensive older males (mean age 64.9 ± 7.2 years). FIELD STRENGTH/SEQUENCE: TOF-MRA sequence with a 3D spoiled gradient echo readout and arterial spin labeling perfusion imaging sequence with a 3D stack-of-spirals fast spin echo readout at 3T. ASSESSMENT: The intracranial arteries were segmented from TOF-MRA and the total length of distal arteries (TLoDA) and number of arterial branches (NoB) were calculated. The mean gray matter cerebral blood flow (GM-CBF) was extracted from arterial spin labeling perfusion imaging. The cognitive level was assessed with short-term and long-term delay-recall auditory verbal learning test (AVLT) scores, and with montreal cognitive assessment. STATISTICAL TESTS: Univariable and multivariable linear regression were used to analyze the associations between TLoDA, NoB, GM-CBF and the cognitive assessment scores, with P < 0.05 indicating significance. RESULTS: TLoDA (r = 0.314) and NoB (r = 0.346) were significantly correlated with GM-CBF. Multivariable linear regression analyses showed that TLoDA and NoB, but not GM-CBF (P = 0.272 and 0.141), were significantly associated with short-term and long-term delay-recall AVLT scores. These associations remained significant after adjusting for GM-CBF. DATA CONCLUSION: The TLoDA and NoB of distal intracranial arteries on TOF-MRA are significantly associated with cognitive impairment in hypertensive subjects. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 3.

2.
J Magn Reson Imaging ; 2023 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-38131254

RESUMO

BACKGROUND: Progression of intracranial atherosclerotic disease (ICAD) is associated with ischemic stroke events and can be quantified with three-dimensional (3D) intracranial vessel wall (IVW) MRI. However, longitudinal 3D IVW studies are limited and ICAD evolution remains relatively unknown. PURPOSE: To evaluate ICAD changes longitudinally and to characterize the imaging patterns of atherosclerotic plaque evolution. STUDY TYPE: Prospective. POPULATION: 37 patients (69 ± 12 years old, 12 females) with angiography confirmed ICAD. FIELD STRENGTH/SEQUENCE: 3.0T/3D time-of-flight gradient echo sequence and T1- and proton density-weighted fast spin echo sequences. ASSESSMENT: Each patient underwent baseline and 1-year follow-up IVW. Then, IVW data from both time points were jointly preprocessed using a multitime point, multicontrast, and multiplanar viewing workflow (known as MOCHA). Lumen and outer wall of plaques were traced and measured, and plaques were then categorized into progression, stable, and regression groups based on changes in plaque wall thickness. Patient demographic and clinical data were collected. Culprit plaques were identified based on cerebral ischemic infarcts. STATISTICAL TESTS: Generalized estimating equations-based linear and logistic regressions were used to assess associations between vascular risk factors, medications, luminal stenosis, IVW plaque imaging features, and longitudinal changes. A two-sided P-value<0.05 was considered statistically significant. RESULTS: Diabetes was significantly associated with ICAD progression, resulting in 6.6% decrease in lumen area and 6.7% increase in wall thickness at 1-year follow-up. After accounting for arterial segments, baseline contrast enhancement predicted plaque progression (odds ratio = 3.61). Culprit plaques experienced an average luminal expansion of 10.9% after 1 year. 74% of the plaques remained stable during follow-up. The regression group (18 plaques) showed significant increase in minimum lumen area (from 7.4 to 8.3 mm2 ), while the progression group (13 plaques) showed significant decrease in minimum lumen area (from 5.4 to 4.3 mm2 ). DATA CONCLUSION: Longitudinal 3D IVW showed ICAD remodeling on the lumen side. Culprit plaques demonstrated longitudinal luminal expansion compared with their non-culprit counterparts. Baseline plaque contrast enhancement and diabetes mellitus were found to be significantly associated with ICAD changes. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 3.

3.
Stroke ; 53(1): 194-200, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34587796

RESUMO

BACKGROUND AND PURPOSE: Two-dimensional high-resolution multicontrast magnetic resonance imaging (2D-MC MRI) is currently the most reliable and reproducible noninvasive carotid vessel wall imaging technique. However, the long scan time required for 2D-MC MRI restricts its practical clinical application. Alternatively, 3-dimensional motion-sensitized driven-equilibrium prepared rapid gradient echo (3D-MERGE) vessel wall MRI can provide high isotropic resolution with extensive coverage in two minutes. In this study, we sought to prove that 3D-MERGE alone can serve as a screening tool to identify advanced carotid lesions. METHODS: Two hundred twenty-seven subjects suspected of recent ischemic stroke or transient ischemic attack were imaged using 2D-MC MRI with an imaging time of 30 minutes, then with 3D-MERGE with an imaging time of 2 minutes, on 3T-MRI scanners. Two experienced reviewers interpreted plaque components using 2D-MC MRI as the reference standard and categorized plaques using a modified American Heart Association lesion classification for MRI. Plaques of American Heart Association type IV and above were classified as advanced. Arteries of American Heart Association types I to II and III were categorized as normal or with early lesions, respectively. One radiologist independently reviewed only 3D-MERGE and labeled the plaques as advanced if they had a wall thickness of >2 mm with high or low signal intensity compared with the adjacent sternocleidomastoid muscle. Sensitivity, specificity, and accuracy for 3D-MERGE were calculated. RESULTS: Four hundred forty-nine arteries from 227 participants (mean age 61.2 years old, 64% male) were included in the analysis. Sensitivity, specificity, and accuracy for identification of advanced lesions on 3D-MERGE were 95.0% (95% CI, 91.8-97.2), 86.9% (95% CI, 81.4-92.0), 93.8% (95% CI, 91.1-95.8), respectively. CONCLUSIONS: 3D-MERGE can accurately identify advanced carotid atherosclerotic plaques in patients suspected of stroke or transient ischemic attack. It has a more extensive coverage and higher sensitivity and specificity for advanced plaque detection with a much shorter acquisition time than 2D-MC MRI. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02017756.


Assuntos
Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/diagnóstico por imagem , Imageamento Tridimensional/métodos , Ataque Isquêmico Transitório/diagnóstico por imagem , AVC Isquêmico/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Idoso , Doenças das Artérias Carótidas/epidemiologia , Estudos Transversais , Imagem Ecoplanar/métodos , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Ataque Isquêmico Transitório/epidemiologia , AVC Isquêmico/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
4.
J Magn Reson Imaging ; 56(3): 944-955, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35099091

RESUMO

BACKGROUND: Three-dimensional (3D) intracranial vessel wall (IVW) magnetic resonance imaging can reliably image intracranial atherosclerotic disease (ICAD). However, an integrated, streamlined, and optimized workflow for IVW analysis to provide qualitative and quantitative measurements is lacking. PURPOSE: To propose and evaluate an image analysis pipeline (MOCHA) that can register multicontrast and multitime point 3D IVW for multiplanar review and quantitative plaque characterization. STUDY TYPE: Retrospective. POPULATION: A total of 11 subjects with ICAD (68 ± 10 years old, 6 males). FIELD STRENGTH/SEQUENCE: A 3.0 T, 3D time-of-flight gradient echo sequence and T1- and proton density-weighted fast spin echo sequences. ASSESSMENT: Each participant underwent two IVW sessions within 2 weeks. Scan and rescan IVW images were preprocessed using MOCHA. The presence of atherosclerotic lesions was identified in different intracranial arterial segments by two readers (GC and JS, 12 years of vascular MR imaging experience each) following an established review protocol to reach consensus on each of the reviews. For all locations with identified plaques, plaque length, lumen and vessel wall areas, maximum and mean wall thickness values, normalized wall index and contrast enhancement ratio were measured. STATISTICAL TESTS: Percent agreement and Cohen's κ were used to test scan-rescan reproducibility of detecting plaques using MOCHA. Intraclass correlation coefficient (ICC) and Bland-Altman analysis were used to evaluate scan-rescan reproducibility for plaque morphologic and enhancement measurements. RESULTS: In 150 paired intracranial vessel segments, the overall agreement in plaque detection was 92.7% (κ = 0.822). The ICCs (all ICCs > 0.90) and Bland-Altman plots (no bias observed) indicated excellent scan-rescan reproducibility for all morphologic and enhancement measurements. DATA CONCLUSION: Findings from this study demonstrate that MOCHA provides high scan-rescan reproducibility for identification and quantification of atherosclerosis along multiple intracranial arterial segments and highlight its potential use in characterizing plaque composition and monitoring plaque development. EVIDENCE LEVEL: 4 TECHNICAL EFFICACY: Stage 2.


Assuntos
Angiografia por Ressonância Magnética , Placa Aterosclerótica , Idoso , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Angiografia por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Placa Aterosclerótica/diagnóstico por imagem , Reprodutibilidade dos Testes , Estudos Retrospectivos
5.
J Stroke Cerebrovasc Dis ; 31(10): 106719, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35994880

RESUMO

OBJECTIVES: Non-stenotic plaques have been observed in intracranial arteries but are less understood compared to those in coronary and carotid arteries. We sought to compare plaque distribution and morphology between stenotic and non-stenotic intracranial plaques with MR vessel wall imaging (VWI) and quantitative image analysis. MATERIALS AND METHODS: Twenty-four patients with intracranial arterial stenosis or luminal irregularity on clinical imaging were scanned with a multi-contrast VWI protocol. Plaques were detected as focal wall thickening on co-registered multiplanar reformats of multi-contrast VWI, with assessment of the location and morphology. TOF-MRA was independently reviewed for any appreciable stenosis using the WAISD criteria. RESULTS: Across 504 arterial segments, a total of 80 plaques were detected, including 23 (29%) with stenosis on TOF-MRA, 56 (70%) without, and 1 (1%) not covered by TOF-MRA. Plaques involving the ICA were more likely to be non-stenotic than those involving other segments (80% versus 55%, p = 0.030) whereas the basilar artery (40%) and PCA (33%) had the lowest proportions of non-stenotic plaques. Maximum wall thickness, indicative of plaque burden, correlated poorly with degree of stenosis (p = 0.10) and overlapped substantially between stenotic and non-stenotic plaques (1.9 [1.5, 2.4] versus 2.0 [1.5, 2.2] mm, p = 0.074). CONCLUSIONS: Intracranial plaques without appreciable stenosis on TOF-MRA represent a large proportion of lesions throughout arterial segments but disproportionately affect the ICA. Morphological characterization of plaques with and without stenosis shows that luminal stenosis is a poor indicator of the underlying burden of intracranial atherosclerosis.


Assuntos
Arteriosclerose Intracraniana , Placa Aterosclerótica , Artérias Cerebrais/diagnóstico por imagem , Artérias Cerebrais/patologia , Constrição Patológica/patologia , Humanos , Arteriosclerose Intracraniana/diagnóstico por imagem , Arteriosclerose Intracraniana/patologia , Angiografia por Ressonância Magnética/métodos , Placa Amiloide/patologia , Placa Aterosclerótica/patologia
6.
Magn Reson Med ; 85(1): 316-325, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32738091

RESUMO

PURPOSE: To propose a highly time-efficient imaging technique named improved simultaneous noncontrast angiography and intraplaque hemorrhage (iSNAP) for simultaneous assessment of lumen, vessel wall, and blood flow in intracranial arteries. METHODS: iSNAP consists of pulsed arterial spin labeling preparations and 3D golden angle radial acquisition. Images were reconstructed by k-space weighted image contrast (KWIC) method with optimized data-sharing strategies. Dynamic MRA for blood flow assessment was obtained from iSNAP by reconstruction at multiple inversion times and image subtraction, static MRA by both image subtraction approach and phase-sensitive inversion recovery technique, and vessel wall images by both reconstruction at zero-crossing time-point of blood and phase-sensitive inversion recovery. A T1 -weighted brain MRI was also reconstructed from iSNAP. Preliminary comparison of iSNAP against the dedicated dynamic MRA sequence 4D-TRANCE, MRA/vessel wall imaging sequence SNAP, and vessel wall imaging sequence T1 -weighted VISTA was performed in healthy volunteers and patients. RESULTS: iSNAP has whole-brain coverage and takes ~6.5 min. The dedicated reconstruction strategies are feasible for each iSNAP image contrast and beneficial for image SNR. iSNAP-dynamic MRA yields similar dynamic flow information as 4D-TRANCE and allows more flexible temporal resolution. The 2 types of iSNAP static MRA images complement each other in characterizing both proximal large arteries and distal small arteries. Depiction of vessel wall lesions in iSNAP vessel wall images is better than SNAP and may be similar to T1 -weighted VISTA, although the images are slightly blurred. CONCLUSION: iSNAP provides a time-efficient evaluation of intracranial arteries and may have great potential for comprehensive assessment of intracranial vascular conditions using a single sequence.


Assuntos
Imageamento Tridimensional , Angiografia por Ressonância Magnética , Encéfalo/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Marcadores de Spin
7.
Magn Reson Med ; 86(3): 1662-1673, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33885165

RESUMO

PURPOSE: To develop and evaluate a domain adaptive and fully automated review workflow (lesion assessment through tracklet evaluation, LATTE) for assessment of atherosclerotic disease in 3D carotid MR vessel wall imaging (MR VWI). METHODS: VWI of 279 subjects with carotid atherosclerosis were used to develop LATTE, mainly convolutional neural network (CNN)-based domain adaptive lesion classification after image quality assessment and artery of interest localization. Heterogeneity in test sets from various sites usually causes inferior CNN performance. With our novel unsupervised domain adaptation (DA), LATTE was designed to accurately classify arteries into normal arteries and early and advanced lesions without additional annotations on new datasets. VWI of 271 subjects from four datasets (eight sites) with slightly different imaging parameters/signal patterns were collected to assess the effectiveness of DA of LATTE using the area under the receiver operating characteristic curve (AUC) on all lesions and advanced lesions before and after DA. RESULTS: LATTE had good performance with advanced/all lesion classification, with the AUC of >0.88/0.83, significant improvements from >0.82/0.80 if without DA. CONCLUSIONS: LATTE can locate target arteries and distinguish carotid atherosclerotic lesions with consistently improved performance with DA on new datasets. It may be useful for carotid atherosclerosis detection and assessment on various clinical sites.


Assuntos
Aterosclerose , Doenças das Artérias Carótidas , Inteligência Artificial , Aterosclerose/diagnóstico por imagem , Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/diagnóstico por imagem , Humanos , Imageamento Tridimensional , Imageamento por Ressonância Magnética
8.
Eur Radiol ; 31(4): 2233-2241, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32929643

RESUMO

OBJECTIVES: The study aimed to analyze the association between hypertension control and subclinical cerebrovascular health using a comprehensive multimodal imaging approach. METHODS: The study included 200 hypertensive older males without previous cardiovascular diseases. Clinic blood pressure (BP) was measured using a standard approach. Cerebrovascular health was evaluated using magnetic resonance imaging in the following four aspects: Intracranial atherosclerosis as determined by vessel wall imaging; Vascular rarefaction (defined as less discernible vessels on angiography) was evaluated using a custom-developed technique. Cerebral blood flow (CBF) and white matter hyperintensity (WMH) were assessed using arterial spin-labeling imaging and fluid-attenuated inversion recovery imaging, respectively. RESULTS: A total of 189 subjects had MRI scans. The mean age was 64.9 (± 7.2) years. For intracranial atherosclerosis, there was a significant association between uncontrolled hypertension and presence of intracranial plaque. When systolic and diastolic BP were analyzed separately, the association remained significant for both. For vascular rarefaction, uncontrolled hypertension was associated with less discernible vessel branches or shorter vessel length on angiography. Further analysis revealed that this is due to uncontrolled diastolic BP, but not uncontrolled systolic BP. There was an association between uncontrolled hypertension and reduced CBF, which was also mainly driven by uncontrolled diastolic BP. We also found that uncontrolled diastolic BP, but not uncontrolled systolic BP, was associated with increased WMH volume. CONCLUSIONS: Uncontrolled hypertension was associated with subclinical cerebrovascular injury globally, with both small and medium-to-large arteries being affected. KEY POINTS: • In this study, we leveraged the advantage of a series of cutting-edge MR imaging and analysis techniques and found uncontrolled hypertension is associated with subclinical globally compromised cerebrovascular health. • The detrimental consequences of uncontrolled BP affect not only the small vessels but also the medium-to-large arteries, and uncontrolled systolic and diastolic BP are both independently associated with certain types of cerebrovascular injury. • Our data suggest that cerebrovascular health is impaired globally in uncontrolled hypertension before the onset of stroke.


Assuntos
Transtornos Cerebrovasculares , Hipertensão , Idoso , Pressão Sanguínea , Circulação Cerebrovascular , Transtornos Cerebrovasculares/complicações , Transtornos Cerebrovasculares/diagnóstico por imagem , Humanos , Hipertensão/complicações , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Imagem Multimodal , Fatores de Risco
9.
Cerebrovasc Dis ; 50(1): 108-120, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33440369

RESUMO

BACKGROUND: In the last 20-30 years, there have been many advances in imaging and therapeutic strategies for symptomatic and asymptomatic individuals with carotid artery stenosis. Our aim was to examine contemporary multinational practice standards. METHODS: Departmental Review Board approval for this study was obtained, and 3 authors prepared the 44 multiple choice survey questions. Endorsement was obtained by the European Society of Neuroradiology, American Society of Functional Neuroradiology, and African Academy of Neurology. A link to the online questionnaire was sent to their respective members and members of the Faculty Advocating Collaborative and Thoughtful Carotid Artery Treatments (FACTCATS). The questionnaire was open from May 16 to July 16, 2019. RESULTS: The responses from 223 respondents from 46 countries were included in the analyses including 65.9% from academic university hospitals. Neuroradiologists/radiologists comprised 68.2% of respondents, followed by neurologists (15%) and vascular surgeons (12.9%). In symptomatic patients, half (50.4%) the respondents answered that the first exam they used to evaluate carotid bifurcation was ultrasound, followed by computed tomography angiography (CTA, 41.6%) and then magnetic resonance imaging (MRI 8%). In asymptomatic patients, the first exam used to evaluate carotid bifurcation was ultrasound in 88.8% of respondents, CTA in 7%, and MRA in 4.2%. The percent stenosis upon which carotid endarterectomy or stenting was recommended was reduced in the presence of imaging evidence of "vulnerable plaque features" by 66.7% respondents for symptomatic patients and 34.2% for asymptomatic patients with a smaller subset of respondents even offering procedural intervention to patients with <50% symptomatic or asymptomatic stenosis. CONCLUSIONS: We found heterogeneity in current practices of carotid stenosis imaging and management in this worldwide survey with many respondents including vulnerable plaque imaging into their decision analysis despite the lack of proven benefit from clinical trials. This study highlights the need for new clinical trials using vulnerable plaque imaging to select high-risk patients despite maximal medical therapy who may benefit from procedural intervention.


Assuntos
Estenose das Carótidas/diagnóstico por imagem , Estenose das Carótidas/terapia , Endarterectomia das Carótidas/tendências , Procedimentos Endovasculares/tendências , Neuroimagem/tendências , Angiografia Cerebral/tendências , Angiografia por Tomografia Computadorizada/tendências , Pesquisas sobre Atenção à Saúde , Humanos , Padrões de Prática Médica/tendências , Valor Preditivo dos Testes , Resultado do Tratamento , Ultrassonografia/tendências
10.
Eur J Nutr ; 60(8): 4555-4563, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34146142

RESUMO

PURPOSE: Dietary sodium and potassium intake are associated with stroke, but the potential mechanisms are unclear. We aimed to study the association between sodium and potassium intake and subclinical cerebrovascular health in hypertensive older males using multimodal magnetic resonance imaging. METHODS: A total of 189 hypertensive male subjects without previous cardiovascular or cerebrovascular disease were included. Daily urinary sodium and potassium excretion were estimated from a fasting spot urine sample using a formula approach. A dedicated cerebrovascular health imaging protocol including vessel wall imaging, angiography, arterial spin labeling imaging and T2-weighted fluid-attenuated inversion recovery imaging was performed to study intracranial atherosclerosis, vascular rarefaction (defined as fewer discernible vessels on angiography), brain perfusion and small vessel disease, respectively. RESULTS: The mean age was 64.9 (± 7.2) years. The average daily urinary and potassium excretion was 4.7 (± 1.4) g/L and 2.1 (± 0.5) g/L, respectively. Increased urinary sodium excretion was associated with decreased cerebral blood flow and elevated urinary potassium excretion was associated with reduced prevalence of intracranial plaque. The associations remained significant after adjusting for covariates, even including blood pressure control. Quadratic regression analysis indicated a marginally significant U-shaped association between urinary sodium intake and white matter hyperintensity, which lost significance in fully adjusted models. No significant association of urinary sodium and potassium excretion with other cerebrovascular health measures was noted. CONCLUSION: We concluded that in hypertensive older males without overt cardiovascular disease, increased sodium intake and reduced potassium intake are associated with impaired subclinical cerebrovascular health.


Assuntos
Potássio , Sódio na Dieta , Idoso , Pressão Sanguínea , Humanos , Masculino , Pessoa de Meia-Idade , Imagem Multimodal , Sódio
11.
Curr Cardiol Rep ; 23(11): 161, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34599416

RESUMO

PURPOSE OF REVIEW: Carotid artery stenosis is a major risk factor for ischemic stroke. Although effective treatment options exist, careful assessment of benefits and risks for individual patients is needed in clinical decision-making. This article reviews contemporary treatments for carotid artery stenosis, the underlying evidence, and areas of uncertainties. RECENT FINDINGS: Specific recommendations are available to guide the standard of care of carotid artery stenosis. Nonetheless, significant uncertainties are noted in patient selection for surgical treatment of asymptomatic carotid stenosis and in optimal treatment targets for pharmacological therapies. Advanced imaging has been used to predict future risk of ipsilateral stroke and clarify mechanisms of actions of pharmacological therapies, primarily in observational studies. Pharmacological and surgical treatments for extracranial carotid artery stenosis continue to evolve with many relevant clinical trials completed and clinical guidelines updated in recent years. Future clinical trials to tackle the areas of uncertainties are warranted.


Assuntos
Doenças das Artérias Carótidas , Estenose das Carótidas , Endarterectomia das Carótidas , Acidente Vascular Cerebral , Angioplastia , Doenças das Artérias Carótidas/complicações , Doenças das Artérias Carótidas/diagnóstico por imagem , Estenose das Carótidas/complicações , Humanos , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/prevenção & controle
12.
Stroke ; 51(2): 475-480, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31902332

RESUMO

Background and Purpose- High-resolution magnetic resonance imaging is capable of characterizing carotid atherosclerotic plaque morphology and composition. Most reported carotid plaque imaging techniques are 2-dimensional (2D) based with limited longitudinal coverage of ≈30 mm, which may be insufficient for complete visualization of extracranial carotid atheroma. A 3D black-blood imaging technique, motion-sensitized driven equilibrium prepared rapid gradient echo technique (3D-MERGE) can provide larger coverage. We sought to use 3D-MERGE to investigate carotid atherosclerosis plaque distribution and to analyze their correlation with clinical information and stroke risk factors. Methods- From 5 hospitals in China, 97 subjects suspected of recent stroke or transient ischemic attack were imaged with 3D-MERGE within 2 weeks of symptoms using 3T magnetic resonance imaging. Images were analyzed by 2 reviewers. Plaque length was calculated and categorized as plaques within, partially outside, or completely outside of typical 2D magnetic resonance imaging coverage. Associations between plaque features and clinical information, stroke risk factors were assessed. Results- Ninety-seven subjects with 194 carotid arteries (70 men and 27 women, mean age 60 years) were analyzed. Of the 136 plaques identified, 68 (50%) were within, 46 (33.8%) were partially outside, and 22 (16.2%) were completely outside of 2D magnetic resonance imaging coverage. Total plaque length was significantly positively associated with male sex (P<0.001), hypertension (P=0.011), and history of smoking (P<0.001). Hypertensive subjects were more likely to have at least one plaque completely outside the 2D magnetic resonance imaging coverage than nonhypertensive subjects (P=0.007). Conclusions- The 3D-MERGE allows for the identification of substantially more carotid plaques than 2D black-blood techniques. The extent and distribution of plaque, identified by the larger coverage afforded by 3D-MERGE, were found to correlate significantly with male sex and risk factors that are common among patients with stroke, including hypertension and history of cigarette smoking.


Assuntos
Doenças das Artérias Carótidas/diagnóstico por imagem , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Placa Aterosclerótica/diagnóstico por imagem , Acidente Vascular Cerebral/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Hipertensão/epidemiologia , Ataque Isquêmico Transitório/epidemiologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fatores Sexuais , Fumar/epidemiologia , Adulto Jovem
13.
Magn Reson Med ; 84(4): 2147-2160, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32162395

RESUMO

PURPOSE: To develop a fully automated vessel wall (VW) analysis workflow (fully automated and robust analysis technique for popliteal artery evaluation, FRAPPE) on the popliteal artery in standardized knee MR images. METHODS: Popliteal artery locations were detected from each MR slice by a deep neural network model and connected into a 3D artery centerline. Vessel wall regions around the centerline were then segmented using another neural network model for segmentation in polar coordinate system. Contours from vessel wall segmentations were used for vascular feature calculation, such as mean wall thickness and wall area. A transfer learning and active learning framework was applied in training the localization and segmentation neural network models to maintain accuracy while reducing manual annotations. This new popliteal artery analysis technique (FRAPPE) was validated against manual segmentation qualitatively and quantitatively in a series of 225 cases from the Osteoarthritis Initiative (OAI) dataset. RESULTS: FRAPPE demonstrated high accuracy and robustness in locating popliteal arteries, segmenting artery walls, and quantifying arterial features. Qualitative evaluations showed 1.2% of slices had noticeable major errors, including segmenting the wrong target and irregular vessel wall contours. The mean Dice similarity coefficient with manual segmentation was 0.79, which is comparable to inter-rater variations. Repeatability evaluations show most of the vascular features have good to excellent repeatability from repeated scans of same subjects, with intra-class coefficient ranging from 0.80 to 0.98. CONCLUSION: This technique can be used in large population-based studies, such as OAI, to efficiently assess the burden of atherosclerosis from routine MR knee scans.


Assuntos
Imageamento por Ressonância Magnética , Artéria Poplítea , Humanos , Redes Neurais de Computação , Artéria Poplítea/diagnóstico por imagem
14.
J Vasc Surg ; 69(4): 1121-1128, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30301684

RESUMO

BACKGROUND: The benefit for carotid endarterectomy (CEA) to prevent a potential stroke has been shown to be less beneficial for women compared with men and the risk of carotid stenting (CAS) is higher in women than men. We hypothesized that a community-based Washington state registry data would also reveal increased morbidity and mortality for women undergoing carotid interventions. METHODS: Deidentified data for CEA and CAS between 2010 and 2015 were obtained from 19 hospitals participating in the Washington State Vascular-Interventional Surgical Care and Outcomes Assessment Program. Data analysis compared in-hospital composite outcome of stroke and mortality from CEA and CAS between women and men. RESULTS: Over the study period, 3704 individuals underwent CEA (n = 2759; 49.5% symptomatic) and CAS (n = 945; 60.9% symptomatic). Women accounted for 39.5% of the cohort. Women were slightly younger than men (70.0 ± 10.2 vs 71.0 ± 9.6 years respectively; P < .01), less likely to be smokers (70.1% vs 75.6%; P < .01), and less likely to have a diagnosis of coronary artery disease (32.9% vs 46.5%; P < .01). Fewer women underwent CEA for symptomatic carotid disease (46.1% vs 51.8%; P < .01). There were no statistically significant differences in the postoperative in-hospital stroke and mortality among women and men undergoing CEA (asymptomatic, 0.8% vs 1.4% [P = .36]; symptomatic, 1.8% vs 2.2% [P = .58]) and CAS (asymptomatic, 1.4% vs 2.2% [P = .56]; symptomatic, 4.6% vs 2.5% [P = .18]). Hospital duration of stay and discharge disposition were similar for women and men. A subanalysis of the octogenarian cohort undergoing CAS demonstrated a substantial increase in-hospital stroke and mortality among women and men (11.6% [CAS] vs 2.2% [CEA]; P = .024). CONCLUSIONS: In the Washington state Vascular-Interventional Surgical Care and Outcomes Assessment Program registry, hospital composite outcome of stroke and mortality following carotid interventions from 2010 to 2015 were noted to be similar for women and men. The notable exception to this finding was observed in subcohort of women undergoing CAS for symptomatic carotid disease at age 80 years or older. These findings should be taken into account when risk stratifying patients for carotid interventions.


Assuntos
Doenças das Artérias Carótidas/terapia , Endarterectomia das Carótidas , Procedimentos Endovasculares , Idoso , Idoso de 80 Anos ou mais , Doenças das Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/mortalidade , Bases de Dados Factuais , Endarterectomia das Carótidas/efeitos adversos , Endarterectomia das Carótidas/mortalidade , Procedimentos Endovasculares/efeitos adversos , Procedimentos Endovasculares/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sistema de Registros , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores Sexuais , Acidente Vascular Cerebral/etiologia , Fatores de Tempo , Resultado do Tratamento , Washington
15.
J Magn Reson Imaging ; 50(4): 1055-1062, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30861249

RESUMO

BACKGROUND: Presence of intraplaque hemorrhage (IPH) is a known risk factor for stroke and plaque progression. Accurate and reproducible measurement of IPH volume are required for further risk stratification. PURPOSE: To develop a semiautomatic method to measure carotid IPH volume. STUDY TYPE: Retrospective. POPULATION: Patients scheduled for carotid endarterectomy and patients with 16-79% asymptomatic carotid stenosis by ultrasound. FIELD STRENGTH: 3T. SEQUENCE: Simultaneous noncontrast angiography and intraplaque hemorrhage (SNAP) MRI. ASSESSMENT: A semiautomated volumetric measurement of IPH using signal intensity thresholding of 3D SNAP volume was implemented. Fourteen carotid endarterectomy patients were enrolled to determine the signal intensity threshold of IPH using histology. Thirty-three patients with 16-79% asymptomatic stenosis were scanned twice within 1 month to evaluate reproducibility. The normalized SNAP intensity with the highest Youden index for predicting IPH on histology was used for thresholding. Scan-rescan reproducibility of IPH measurement was assessed using the intraclass correlation coefficient (ICC) and coefficient of variation (CV). STATISTICAL TESTS: Receiver operating characteristic curve, area under the curve, Cohen's kappa, intraclass correlation coefficient, coefficient of variance (CV), and paired t-test. RESULTS: IPH detection by the algorithm had substantial agreement with manual review (kappa: 0.92; 95% confidence interval [CI]: 0.83, 1.00) and moderate agreement with histology (kappa: 0.55; 95% CI: 0.34, 0.68). IPH volume measurements by the algorithm were strongly correlated with histology (Spearman's rho = 0.76, P = 0.002). IPH measurements were also reproducible, with ICCs of 0.86 (95% CI: 0.57, 0.96), 0.77 (95% CI: 0.32, 0.94), and 0.99 (95% CI: 0.93, 1.00) for maximum/mean normalized intensity and IPH volume, respectively. The corresponding CVs were 10.6%, 5.2%, and 11.8%. DATA CONCLUSION: IPH volume measurements on SNAP MRI are highly reproducible using semiautomatic measurement. Level of Evidence 2 Technical Efficacy Stage 2 J. Magn. Reson. Imaging 2019;50:1055-1062.


Assuntos
Artérias Carótidas/diagnóstico por imagem , Hemorragia/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Placa Aterosclerótica/complicações , Placa Aterosclerótica/diagnóstico por imagem , Idoso , Artérias Carótidas/patologia , Feminino , Hemorragia/patologia , Humanos , Masculino , Placa Aterosclerótica/patologia , Reprodutibilidade dos Testes , Estudos Retrospectivos
16.
Arterioscler Thromb Vasc Biol ; 38(4): 927-934, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29472231

RESUMO

OBJECTIVE: Early atherosclerosis is often undetected due in part to compensatory enlargement of the outer wall, termed positive remodeling. Variations in hemodynamic conditions and clinical factors influence the patterns of remodeling. The carotid artery provides an opportunity to examine these variations because of the unique geometry of the carotid bulb. This study aimed to determine differences in remodeling of the common, internal, and bifurcation segments of the carotid using magnetic resonance imaging. APPROACH AND RESULTS: Carotid arteries of 525 subjects without history of cardiovascular disease were imaged by magnetic resonance imaging. The carotid artery was divided into 3 segments: common carotid artery; bifurcation; and internal carotid artery. Remodeling patterns were characterized using linear regression analysis of lumen and total vessel areas (dependent variables) compared with maximum wall thickness (independent variable) for each segment, adjusted for age, sex, and height. The common carotid artery demonstrated a pattern consistent with positive remodeling, whereas the bifurcation demonstrated negative remodeling. The internal carotid artery demonstrated a mixed pattern of outer wall expansion and lumen constriction. Females and subjects with diabetes mellitus showed more positive remodeling, hypertension was associated with attenuated positive remodeling, and those with hypercholesterolemia showed more negative remodeling. CONCLUSIONS: In this cohort of 55- to 80-year-old individuals without history of cardiovascular disease, the pattern of early carotid artery remodeling was segment specific and appeared to be associated with sex and clinical characteristics. These findings provide the groundwork for longitudinal studies to define local and systemic factors such as hemodynamic and clinical conditions on carotid artery remodeling.


Assuntos
Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/diagnóstico por imagem , Angiografia por Ressonância Magnética , Remodelação Vascular , Idoso , Idoso de 80 Anos ou mais , Artérias Carótidas/patologia , Artérias Carótidas/fisiopatologia , Doenças das Artérias Carótidas/patologia , Doenças das Artérias Carótidas/fisiopatologia , Chicago , Estudos Transversais , Diagnóstico Precoce , Feminino , Florida , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Fatores de Risco , Fatores Sexuais
17.
Arterioscler Thromb Vasc Biol ; 38(3): 673-678, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29301785

RESUMO

OBJECTIVE: To assess whether Lp(a) (lipoprotein(a)) levels and other lipid levels were predictive of progression of atherosclerosis burden as assessed by carotid magnetic resonance imaging in subjects who have been treated with LDL-C (low-density lipoprotein cholesterol)-lowering therapy and participated in the AIM-HIGH trial (Atherothrombosis Intervention in Metabolic Syndrome With Low HDL/High Triglycerides: Impact on Global Health Outcomes). APPROACH AND RESULTS: AIM-HIGH was a randomized, double-blind study of subjects with established vascular disease, elevated triglycerides, and low HDL-C (high-density lipoprotein cholesterol). One hundred fifty-two AIM-HIGH subjects underwent both baseline and 2-year follow-up carotid artery magnetic resonance imaging. Plaque burden was measured by the percent wall volume (%WV) of the carotid artery. Associations between annualized change in %WV with baseline and on-study (1 year) lipid variables were evaluated using multivariate linear regression and the Bonferroni correction to account for multiple comparisons. Average %WV at baseline was 41.6±6.8% and annualized change in %WV over 2 years ranged from -3.2% to 3.7% per year (mean: 0.2±1.1% per year; P=0.032). Increases in %WV were significantly associated with higher baseline Lp(a) (ß=0.34 per 1-SD increase of Lp(a); 95% confidence interval, 0.15-0.52; P<0.001) after adjusting for clinical risk factors and other lipid levels. On-study Lp(a) had a similar positive association with %WV progression (ß=0.33; 95% confidence interval, 0.15-0.52; P<0.001). CONCLUSIONS: Despite intensive lipid therapy, aimed at aggressively lowering LDL-C to <70 mg/dL, carotid atherosclerosis continued to progress as assessed by carotid magnetic resonance imaging and that elevated Lp(a) levels were independent predictors of increases in atherosclerosis burden.


Assuntos
Artérias Carótidas/efeitos dos fármacos , Doenças das Artérias Carótidas/tratamento farmacológico , Hipolipemiantes/uso terapêutico , Lipoproteína(a)/sangue , Angiografia por Ressonância Magnética , Placa Aterosclerótica , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Artérias Carótidas/diagnóstico por imagem , Artérias Carótidas/patologia , Doenças das Artérias Carótidas/sangue , Doenças das Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/patologia , LDL-Colesterol/sangue , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
18.
Magn Reson Med ; 79(6): 3229-3238, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29044753

RESUMO

PURPOSE: To develop a quantitative intracranial artery measurement technique to extract comprehensive artery features from time-of-flight MR angiography (MRA). METHODS: By semiautomatically tracing arteries based on an open-curve active contour model in a graphical user interface, 12 basic morphometric features and 16 basic intensity features for each artery were identified. Arteries were then classified as one of 24 types using prediction from a probability model. Based on the anatomical structures, features were integrated within 34 vascular groups for regional features of vascular trees. Eight 3D MRA acquisitions with intracranial atherosclerosis were assessed to validate this technique. RESULTS: Arterial tracings were validated by an experienced neuroradiologist who checked agreement at bifurcation and stenosis locations. This technique achieved 94% sensitivity and 85% positive predictive values (PPV) for bifurcations, and 85% sensitivity and PPV for stenosis. Up to 1,456 features, such as length, volume, and averaged signal intensity for each artery, as well as vascular group in each of the MRA images, could be extracted to comprehensively reflect characteristics, distribution, and connectivity of arteries. Length for the M1 segment of the middle cerebral artery extracted by this technique was compared with reviewer-measured results, and the intraclass correlation coefficient was 0.97. CONCLUSION: A semiautomated quantitative method to trace, label, and measure intracranial arteries from 3D-MRA was developed and validated. This technique can be used to facilitate quantitative intracranial vascular research, such as studying cerebrovascular adaptation to aging and disease conditions. Magn Reson Med 79:3229-3238, 2018. © 2017 International Society for Magnetic Resonance in Medicine.


Assuntos
Artérias Cerebrais/diagnóstico por imagem , Imageamento Tridimensional/métodos , Angiografia por Ressonância Magnética/métodos , Adulto , Idoso , Algoritmos , Feminino , Humanos , Arteriosclerose Intracraniana/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade
19.
J Vasc Surg ; 68(6): 1640-1648, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29804742

RESUMO

OBJECTIVE: Congenital aortic arch variations are more common in patients with thoracic aortic disease for reasons unknown. Additionally, little is understood about their relation to type B aortic dissections (TBAD) specifically. We investigated the prevalence of variant aortic arch anatomy in patients with TBAD compared with controls. To understand the implications of how variant aortic arch anatomy may contribute to degenerative aortic disease, we compared flow hemodynamics of three variations of aortic arches using four-dimensional flow magnetic resonance imaging (4D flow MRI). METHODS: Arch anatomy on computed tomography imaging was reviewed and compared between patients with TBAD and age/sex-matched controls free of aortic pathology. Arch variants were defined as follows: common origin of innominate and left common carotid artery (bovine arch), aberrant right subclavian artery, and right-sided aortic arch. Demographics, TBAD characteristics, and follow-up data were abstracted. Patients with TBAD with variant and conventional aortic arches were compared. Additionally, three matched healthy controls with conventional, bovine, and aberrant right subclavian artery arches underwent 4D flow MRI evaluation to assess if there were differences in flow patterns by arch type. Indices of regional hemodynamic wall sheer stress were compared. RESULTS: Computed tomography scans of 185 patients with TBAD (mean age, 58.1 ± 12.4 years; 72.4% males; 71.4% Caucasian) and 367 controls (mean age, 62.5 ± 13.4 years; 67% males; 77.9% Caucasian) were reviewed. Variant arch anatomy was more prevalent in patients with TBAD (40.5% vs 24.5%; P < .001). In patients with TBAD, there were no differences in the mean age of presentation and descending thoracic aorta diameter among those with variant or conventional arch anatomy. Patients with TBAD with variant arch anatomy had a higher percentage of dissection related thoracic aortic repairs (54.7% vs 33.6%; P = .004) with repairs occurring predominantly in the acute phase. 4D flow MRI demonstrated a higher systolic wall shear stress along the inner curve of the bovine arch compared with the conventional aberrant right subclavian artery arches. CONCLUSIONS: Variant aortic arch anatomy is significantly more prevalent in patients with TBAD. patients with TBAD with variant arch anatomy had a higher percentage of dissection-related aortic repair. Preliminary 4D flow MRI data show differences in hemodynamic flow patterns between variant and conventional arches. Studies of long-term outcomes based on arch anatomy may offer additional insight to TBAD genesis and possibly influence management decisions.


Assuntos
Aorta Torácica/fisiopatologia , Aneurisma da Aorta Torácica/fisiopatologia , Dissecção Aórtica/fisiopatologia , Hemodinâmica , Adulto , Idoso , Idoso de 80 Anos ou mais , Dissecção Aórtica/diagnóstico por imagem , Dissecção Aórtica/epidemiologia , Aorta Torácica/anormalidades , Aorta Torácica/diagnóstico por imagem , Aneurisma da Aorta Torácica/diagnóstico por imagem , Aneurisma da Aorta Torácica/epidemiologia , Aortografia/métodos , Velocidade do Fluxo Sanguíneo , Angiografia por Tomografia Computadorizada , Feminino , Humanos , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Imagem de Perfusão/métodos , Prevalência , Fluxo Sanguíneo Regional , Estudos Retrospectivos , Washington/epidemiologia , Adulto Jovem
20.
BMC Bioinformatics ; 18(1): 229, 2017 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-28464789

RESUMO

BACKGROUND: Image registration is an important research topic in the field of image processing. Applying image registration to vascular image allows multiple images to be strengthened and fused, which has practical value in disease detection, clinical assisted therapy, etc. However, it is hard to register vascular structures with high noise and large difference in an efficient and effective method. RESULTS: Different from common image registration methods based on area or features, which were sensitive to distortion and uncertainty in vascular structure, we proposed a novel registration method based on network structure and circuit simulation. Vessel images were transformed to graph networks and segmented to branches to reduce the calculation complexity. Weighted graph networks were then converted to circuits, in which node voltages of the circuit reflecting the vessel structures were used for node registration. The experiments in the two-dimensional and three-dimensional simulation and clinical image sets showed the success of our proposed method in registration. CONCLUSIONS: The proposed vascular image registration method based on network structure and circuit simulation is stable, fault tolerant and efficient, which is a useful complement to the current mainstream image registration methods.


Assuntos
Angiografia/métodos , Processamento de Imagem Assistida por Computador/métodos , Humanos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA