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1.
AJNR Am J Neuroradiol ; 43(2): 265-271, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35121587

RESUMO

BACKGROUND AND PURPOSE: Intraplaque hemorrhage contributes to lipid core enlargement and plaque progression, leading to plaque destabilization and stroke. The mechanisms that contribute to the development of intraplaque hemorrhage are not completely understood. A higher incidence of intraplaque hemorrhage and thin/ruptured fibrous cap (upstream of the maximum stenosis in patients with severe [≥70%] carotid stenosis) has been reported. We aimed to noninvasively study the distribution of intraplaque hemorrhage and a thin/ruptured fibrous cap in patients with mild-to-moderate carotid stenosis. MATERIALS AND METHODS: Eighty-eight symptomatic patients with stroke (<70% carotid stenosis included in the Plaque at Risk study) demonstrated intraplaque hemorrhage on MR imaging in the carotid artery plaque ipsilateral to the side of TIA/stroke. The intraplaque hemorrhage area percentage was calculated. A thin/ruptured fibrous cap was scored by comparing pre- and postcontrast black-blood TSE images. Differences in mean intraplaque hemorrhage percentages between the proximal and distal regions were compared using a paired-samples t test. The McNemar test was used to reveal differences in proportions of a thin/ruptured fibrous cap. RESULTS: We found significantly larger areas of intraplaque hemorrhage in the proximal part of the plaque at 2, 4, and 6 mm from the maximal luminal narrowing, respectively: 14.4% versus 9.6% (P = .04), 14.7% versus 5.4% (P < .001), and 11.1% versus 2.2% (P = .001). Additionally, we found an increased proximal prevalence of a thin/ruptured fibrous cap on MR imaging at 2, 4, 6, and 8 mm from the MR imaging section with the maximal luminal narrowing, respectively: 33.7% versus 18.1%, P = .007; 36.1% versus 7.2%, P < .001; 33.7% versus 2.4%, P = .001; and 30.1% versus 3.6%, P = .022. CONCLUSIONS: We demonstrated that intraplaque hemorrhage and a thin/ruptured fibrous cap are more prevalent on the proximal side of the plaque compared with the distal side in patients with mild-to-moderate carotid stenosis.


Assuntos
Estenose das Carótidas , Placa Aterosclerótica , Acidente Vascular Cerebral , Artérias Carótidas/diagnóstico por imagem , Estenose das Carótidas/complicações , Estenose das Carótidas/diagnóstico por imagem , Estenose das Carótidas/epidemiologia , Hemorragia/complicações , Hemorragia/diagnóstico por imagem , Hemorragia/epidemiologia , Humanos , Imageamento por Ressonância Magnética , Placa Aterosclerótica/complicações , Placa Aterosclerótica/diagnóstico por imagem , Acidente Vascular Cerebral/etiologia
2.
MycoKeys ; 79: 17-118, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33958950

RESUMO

This is the first study exclusively dedicated to the study of Hebeloma in Greenland. It is based on almost 400 collections, the great majority of which were collected by three of the co-authors over a period of 40 years and were lodged in the fungarium of the Natural History Museum in Copenhagen. The material was identified using molecular and morphological methods. In total, 28 species were recognized, 27 belonging to three sections, H. sects Hebeloma, Denudata and Velutipes. One species sampled was new to science and is here described as H. arcticum. For all species, a description, a distribution map within Greenland and macro and microphotographs are presented. A key is provided for the 28 species. The distribution of species within Greenland is discussed. The findings are placed in the context of studies of arctic and alpine Hebeloma from other parts of the world where comparable data exist. Notably, H. grandisporum, H. louiseae and H. islandicum, previously only known from Romania, Svalbard, Iceland or Norway, respectively, have been found in Greenland. The latter is also the only species encountered that does not belong to any of the above sections. Hebeloma excedens and H. colvinii - for the latter we here publish the first modern description - are to date only known from continental North America and now Greenland.

3.
Front Bioeng Biotechnol ; 9: 828577, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35155418

RESUMO

The role of wall shear stress (WSS) in atherosclerotic plaque development is evident, but the relation between WSS and plaque composition in advanced atherosclerosis, potentially resulting in plaque destabilization, is a topic of discussion. Using our previously developed image registration pipeline, we investigated the relation between two WSS metrics, time-averaged WSS (TAWSS) and the oscillatory shear index (OSI), and the local histologically determined plaque composition in a set of advanced human carotid plaques. Our dataset of 11 carotid endarterectomy samples yielded 87 histological cross-sections, which yielded 511 radial bins for analysis. Both TAWSS and OSI values were subdivided into patient-specific low, mid, and high tertiles. This cross-sectional study shows that necrotic core (NC) size and macrophage area are significantly larger in areas exposed to high TAWSS or low OSI. Local TAWSS and OSI tertile values were generally inversely related, as described in the literature, but other combinations were also found. Investigating the relation between plaque vulnerability features and different combinations of TAWSS and OSI tertile values revealed a significantly larger cap thickness in areas exposed to both low TAWSS and low OSI. In conclusion, our study confirmed previous findings, correlating high TAWSS to larger macrophage areas and necrotic core sizes. In addition, our study demonstrated new relations, correlating low OSI to larger macrophage areas, and a combination of low TAWSS and low OSI to larger cap thickness.

4.
AJNR Am J Neuroradiol ; 42(1): 144-151, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33214179

RESUMO

BACKGROUND AND PURPOSE: Plaque ulceration is a marker of previous plaque rupture. We studied the association between atherosclerotic plaque composition at baseline and plaque ulceration at baseline and follow-up. MATERIALS AND METHODS: We included symptomatic patients with a carotid stenosis of <70% who underwent MDCTA and MR imaging at baseline (n = 180). MDCTA was repeated at 2 years (n = 73). We assessed the presence of ulceration using MDCTA. Baseline MR imaging was used to assess the vessel wall volume and the presence and volume of plaque components (intraplaque hemorrhage, lipid-rich necrotic core, and calcifications) and the fibrous cap status. Associations at baseline were evaluated with binary logistic regression and reported with an OR and its 95% CI. Simple statistical testing was performed in the follow-up analysis. RESULTS: At baseline, the prevalence of plaque ulceration was 27% (49/180). Increased wall volume (OR = 12.1; 95% CI, 3.5-42.0), higher relative lipid-rich necrotic core (OR = 1.7; 95% CI, 1.3-2.2), higher relative intraplaque hemorrhage volume (OR = 1.7; 95% CI, 1.3-2.2), and a thin-or-ruptured fibrous cap (OR = 3.4; 95% CI, 1.7-6.7) were associated with the presence of ulcerations at baseline. In 8% (6/73) of the patients, a new ulcer developed. Plaques with a new ulceration at follow-up had at baseline a larger wall volume (1.04 cm3 [IQR, 0.97-1.16 cm3] versus 0.86 cm3 [IQR, 0.73-1.00 cm3]; P = .029), a larger relative lipid-rich necrotic core volume (23% [IQR, 13-31%] versus 2% [IQR, 0-14%]; P = .002), and a larger relative intraplaque hemorrhage volume (14% [IQR, 8-24%] versus 0% [IQR, 0-5%]; P < .001). CONCLUSIONS: Large atherosclerotic plaques and plaques with intraplaque hemorrhage and lipid-rich necrotic cores were associated with plaque ulcerations at baseline and follow-up.


Assuntos
Doenças das Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/patologia , Placa Aterosclerótica/diagnóstico por imagem , Placa Aterosclerótica/patologia , Idoso , Feminino , Humanos , Lipídeos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Necrose/patologia , Úlcera/patologia
5.
IEEE Trans Med Imaging ; 39(5): 1535-1544, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31725370

RESUMO

We demonstrate three-dimensional intravascular flow imaging compatible with routine clinical image acquisition workflow by means of megahertz (MHz) intravascular Doppler Optical Coherence Tomography (OCT). The OCT system relies on a 1.1 mm diameter motorized imaging catheter and a 1.5 MHz Fourier Domain Mode Locked (FDML) laser. Using a post processing method to compensate the drift of the FDML laser output, we can resolve the Doppler phase shift between two adjoining OCT A-line datasets. By interpretation of the velocity field as measured around the zero phase shift, the flow direction at specific angles can be qualitatively estimated. Imaging experiments were carried out in phantoms, micro channels, and swine coronary artery in vitro at a speed of 600 frames/s. The MHz wavelength sweep rate of the OCT system allows us to directly investigate flow velocity of up to 37.5 cm/s while computationally expensive phase-unwrapping has to be applied to measure such high speed using conventional OCT system. The MHz sweep rate also enables a volumetric Doppler imaging even with a fast pullback at 40 mm/s. We present the first simultaneously recorded 3D morphological images and Doppler flow profiles. Flow pattern estimation and three-dimensional structural reconstruction of entire coronary artery are achieved using a single OCT pullback dataset.


Assuntos
Vasos Coronários , Tomografia de Coerência Óptica , Animais , Vasos Coronários/diagnóstico por imagem , Imageamento Tridimensional , Lasers , Imagens de Fantasmas , Suínos
6.
PLoS One ; 14(6): e0217271, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31170183

RESUMO

Wall shear stress (WSS), the frictional force exerted on endothelial cells by blood flow, is hypothesised to influence atherosclerotic plaque growth and composition. We developed a methodology for image registration of MR and histology images of advanced human carotid plaques and corresponding WSS data, obtained by MRI and computational fluid dynamics. The image registration method requires four types of input images, in vivo MRI, ex vivo MRI, photographs of transversally sectioned plaque tissue and histology images. These images are transformed to a shared 3D image domain by applying a combination of rigid and non-rigid registration algorithms. Transformation matrices obtained from registration of these images are used to transform subject-specific WSS data to the shared 3D image domain as well. WSS values originating from the 3D WSS map are visualised in 2D on the corresponding lumen locations in the histological sections and divided into eight radial segments. In each radial segment, the correlation between WSS values and plaque composition based on histological parameters can be assessed. The registration method was successfully applied to two carotid endarterectomy specimens. The resulting matched contours from the imaging modalities had Hausdorff distances between 0.57 and 0.70 mm, which is in the order of magnitude of the in vivo MRI resolution. We simulated the effect of a mismatch in the rigid registration of imaging modalities on WSS results by relocating the WSS data with respect to the stack of histology images. A 0.6 mm relocation altered the mean WSS values projected on radial bins on average by 0.59 Pa, compared to the output of original registration. This mismatch of one image slice did not change the correlation between WSS and plaque thickness. In conclusion, we created a method to investigate correlations between WSS and plaque composition.


Assuntos
Artérias Carótidas , Doenças das Artérias Carótidas , Endarterectomia , Hemorreologia , Angiografia por Ressonância Magnética , Placa Aterosclerótica , Resistência ao Cisalhamento , Artérias Carótidas/diagnóstico por imagem , Artérias Carótidas/fisiopatologia , Artérias Carótidas/cirurgia , Doenças das Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/fisiopatologia , Doenças das Artérias Carótidas/cirurgia , Feminino , Humanos , Masculino , Placa Aterosclerótica/diagnóstico por imagem , Placa Aterosclerótica/fisiopatologia , Placa Aterosclerótica/cirurgia
7.
Personal Ment Health ; 13(3): 144-154, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31050190

RESUMO

Meaning in life is a motivational force and an existential theme for many people. The concept of meaning comprises purpose, comprehension and mattering. According to the Section III model of personality disorder (DSM-5), lack of meaning, purpose and direction in life is part of personality dysfunction. The present study aimed to determine the association between personality disorder (PD), personality dysfunction and 'lack of meaning, purpose and direction' as a distinct facet of personality dysfunction, using Livesley's self-report questionnaire-the General Assessment of Personality Disorder. This comparative quantitative study showed significant differences in lack of meaning, purpose and direction between a group of patients with PD (n = 126, PD with depression n = 51 and PD without depression n = 75), a group of non-PD patients (n = 76, with depression n = 27 and without depression n = 49) and a control group (n = 444). The PD groups had similar scores as the non-PD patients with depression. Lack of meaning was significantly associated with 'difficulty setting and attaining goals' in all groups, with 'lack of affiliative relationships' in the PD groups and 'sense of inner emptiness' in the PD group without depression and in controls. © 2019 John Wiley & Sons, Ltd.


Assuntos
Transtornos da Personalidade/psicologia , Personalidade , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Autorrelato , Inquéritos e Questionários , Adulto Jovem
8.
Sci Rep ; 8(1): 14014, 2018 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-30228313

RESUMO

The heart rate lowering drug Ivabradine was shown to improve cardiac outcome in patients with previous heart failure. However, in patients without heart failure, no beneficial effect of Ivabradine was observed. Animal studies suggested a preventive effect of Ivabradine on atherosclerosis which was due to an increase in wall shear stress (WSS), the blood flow-induced frictional force exerted on the endothelium, triggering anti-inflammatory responses. However, data on the effect of Ivabradine on WSS is sparse. We aim to study the effect of Ivabradine on (i) the 3D WSS distribution over a growing plaque and (ii) plaque composition. We induced atherosclerosis in ApoE-/- mice by placing a tapered cast around the right common carotid artery (RCCA). Five weeks after cast placement, Ivabradine was administered via drinking water (15 mg/kg/day) for 2 weeks, after which the RCCA was excised for histology analyses. Before and after Ivabradine treatment, animals were imaged with Doppler Ultrasound to measure blood velocity. Vessel geometry was obtained using contrast-enhanced micro-CT. Time-averaged WSS during systole, diastole and peak WSS was subsequently computed. Ivabradine significantly decreased heart rate (459 ± 28 bpm vs. 567 ± 32 bpm, p < 0.001). Normalized peak flow significantly increased in the Ivabradine group (124.2% ± 40.5% vs. 87.3% ± 25.4%, p < 0.05), reflected by an increased normalized WSS level during systole (110.7% ± 18.4% vs. 75.4% ± 24.6%, p < 0.05). However, plaque size or composition including plaque area, relative necrotic core area and macrophage content were not altered in mice treated with Ivabradine compared to controls. We conclude that increased WSS in response to Ivabradine treatment did not affect plaque progression in a murine model.


Assuntos
Aterosclerose/tratamento farmacológico , Modelos Animais de Doenças , Frequência Cardíaca/fisiologia , Hemodinâmica , Ivabradina/farmacologia , Placa Aterosclerótica/prevenção & controle , Animais , Aterosclerose/patologia , Fármacos Cardiovasculares/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout para ApoE , Placa Aterosclerótica/patologia , Estresse Mecânico
9.
R Soc Open Sci ; 5(3): 171447, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29657758

RESUMO

Wall shear stress (WSS) is involved in atherosclerotic plaque initiation, yet its role in plaque progression remains unclear. We aimed to study (i) the temporal and spatial changes in WSS over a growing plaque and (ii) the correlation between WSS and plaque composition, using animal-specific data in an atherosclerotic mouse model. Tapered casts were placed around the right common carotid arteries (RCCA) of ApoE-/- mice. At 5, 7 and 9 weeks after cast placement, RCCA geometry was reconstructed using contrast-enhanced micro-CT. Lumen narrowing was observed in all mice, indicating the progression of a lumen intruding plaque. Next, we determined the flow rate in the RCCA of each mouse using Doppler Ultrasound and computed WSS at all time points. Over time, as the plaque developed and further intruded into the lumen, absolute WSS significantly decreased. Finally at week 9, plaque composition was histologically characterized. The proximal part of the plaque was small and eccentric, exposed to relatively lower WSS. Close to the cast a larger and concentric plaque was present, exposed to relatively higher WSS. Lower WSS was significantly correlated to the accumulation of macrophages in the eccentric plaque. When pooling data of all animals, correlation between WSS and plaque composition was weak and no longer statistically significant. In conclusion, our data showed that in our mouse model absolute WSS strikingly decreased during disease progression, which was significantly correlated to plaque area and macrophage content. Besides, our study demonstrates the necessity to analyse individual animals and plaques when studying correlations between WSS and plaque composition.

10.
Phys Med Biol ; 63(7): 075015, 2018 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-29508770

RESUMO

Until now, no matrix transducer has been realized for 3D transesophageal echocardiography (TEE) in pediatric patients. In 3D TEE with a matrix transducer, the biggest challenges are to connect a large number of elements to a standard ultrasound system, and to achieve a high volume rate (>200 Hz). To address these issues, we have recently developed a prototype miniaturized matrix transducer for pediatric patients with micro-beamforming and a small central transmitter. In this paper we propose two multiline parallel 3D beamforming techniques (µBF25 and µBF169) using the micro-beamformed datasets from 25 and 169 transmit events to achieve volume rates of 300 Hz and 44 Hz, respectively. Both the realizations use angle-weighted combination of the neighboring overlapping sub-volumes to avoid artifacts due to sharp intensity changes introduced by parallel beamforming. In simulation, the image quality in terms of the width of the point spread function (PSF), lateral shift invariance and mean clutter level for volumes produced by µBF25 and µBF169 are similar to the idealized beamforming using a conventional single-line acquisition with a fully-sampled matrix transducer (FS4k, 4225 transmit events). For completeness, we also investigated a 9 transmit-scheme (3 × 3) that allows even higher frame rates but found worse B-mode image quality with our probe. The simulations were experimentally verified by acquiring the µBF datasets from the prototype using a Verasonics V1 research ultrasound system. For both µBF169 and µBF25, the experimental PSFs were similar to the simulated PSFs, but in the experimental PSFs, the clutter level was ~10 dB higher. Results indicate that the proposed multiline 3D beamforming techniques with the prototype matrix transducer are promising candidates for real-time pediatric 3D TEE.


Assuntos
Ecocardiografia Tridimensional/métodos , Ecocardiografia Transesofagiana/métodos , Coração/diagnóstico por imagem , Imagens de Fantasmas , Ultrassonografia/métodos , Criança , Conjuntos de Dados como Assunto , Humanos , Transdutores
11.
BJOG ; 125(3): 289-297, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28941138

RESUMO

BACKGROUND: To reduce the risk of postoperative stress urinary incontinence (POSUI) prolapse repair might be combined with incontinence surgery. OBJECTIVES: Compare efficacy and safety of prolapse surgery with and without incontinence surgery. SEARCH STRATEGY: Including our earlier review a systematic search in PubMed, EMBASE, the Cochrane Library and the Register of Current Controlled Trials was performed from 1995 to 2017. SELECTION CRITERIA: Randomised trials comparing prolapse surgery with a midurethral sling (MUS) or Burch colposuspension. DATA COLLECTION AND ANALYSIS: Two reviewers selected eligible articles and extracted data. Stress urinary outcomes were pooled for preoperative SUI. Urgency incontinence and adverse events were pooled for incontinence procedure. MAIN RESULTS: Ten trials were included. Women with preoperative SUI symptoms or occult SUI had a lower risk to undergo subsequent incontinence surgery for POSUI after vaginal prolapse surgery with a MUS than after prolapse surgery only: 0 versus 40% [relative risk (RR) 0.0; 95% CI 0.0-0.2] and 1 versus 15% (RR 0.1; 95% CI 0.0-0.6), respectively. These differences were not significant in continent women not tested for occult SUI or without occult SUI. Serious adverse events were more frequent after vaginal prolapse repair with MUS (14 versus 8%; RR 1.7; 95% CI 1.1-2.7), but not after sacrocolpopexy with Burch colposuspension. Combination surgery did not increase the risk of overactive bladder symptoms, urgency incontinence and surgery for voiding dysfunction. CONCLUSIONS: Vaginal prolapse repair with MUS reduced the risk of postoperative SUI in women with preoperative SUI symptoms or occult SUI, but serious adverse events were more frequent. TWEETABLE ABSTRACT: Less stress incontinence after vaginal prolapse repair with sling, but more adverse events.


Assuntos
Procedimentos Cirúrgicos em Ginecologia/métodos , Prolapso de Órgão Pélvico/cirurgia , Complicações Pós-Operatórias/prevenção & controle , Incontinência Urinária por Estresse/prevenção & controle , Procedimentos Cirúrgicos Urológicos/métodos , Feminino , Procedimentos Cirúrgicos em Ginecologia/efeitos adversos , Humanos , Prolapso de Órgão Pélvico/fisiopatologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Slings Suburetrais , Incontinência Urinária por Estresse/cirurgia , Procedimentos Cirúrgicos Urológicos/efeitos adversos
12.
Biomed Opt Express ; 8(2): 943-953, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-28270995

RESUMO

Lipid deposition can be assessed with combined intravascular photoacoustic/ultrasound (IVPA/US) imaging. To date, the clinical translation of IVPA/US imaging has been stalled by a low imaging speed and catheter complexity. In this paper, we demonstrate imaging of lipid targets in swine coronary arteries in vivo, at a clinically useful frame rate of 20 s-1. We confirmed image contrast for atherosclerotic plaque in human samples ex vivo. The system is on a mobile platform and provides real-time data visualization during acquisition. We achieved an IVPA signal-to-noise ratio of 20 dB. These data show that clinical translation of IVPA is possible in principle.

13.
Pediatrics ; 139(1)2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-28028203

RESUMO

In 2009, the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) established the Pediatric Terminology Harmonization Initiative to establish a core library of terms to facilitate the acquisition and sharing of knowledge between pediatric clinical research, practice, and safety reporting. A coalition of partners established a Pediatric Terminology Adverse Event Working Group in 2013 to develop a specific terminology relevant to international pediatric adverse event (AE) reporting. Pediatric specialists with backgrounds in clinical care, research, safety reporting, or informatics, supported by biomedical terminology experts from the National Cancer Institute's Enterprise Vocabulary Services participated. The multinational group developed a working definition of AEs and reviewed concepts (terms, synonyms, and definitions) from 16 pediatric clinical domains. The resulting AE terminology contains >1000 pediatric diseases, disorders, or clinical findings. The terms were tested for proof of concept use in 2 different settings: hospital readmissions and the NICU. The advantages of the AE terminology include ease of adoption due to integration with well-established and internationally accepted biomedical terminologies, a uniquely temporal focus on pediatric health and disease from conception through adolescence, and terms that could be used in both well- and underresourced environments. The AE terminology is available for use without restriction through the National Cancer Institute's Enterprise Vocabulary Services and is fully compatible with, and represented in, the Medical Dictionary for Regulatory Activities. The terminology is intended to mature with use, user feedback, and optimization.


Assuntos
Avaliação de Resultados em Cuidados de Saúde/organização & administração , Pediatria , Terminologia como Assunto , Terapêutica/efeitos adversos , Criança , Humanos , Recém-Nascido , Terapia Intensiva Neonatal , Cooperação Internacional , Vocabulário Controlado
14.
Atherosclerosis ; 251: 348-354, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27263078

RESUMO

BACKGROUND AND AIMS: Carotid artery plaques with vulnerable plaque components are related to a higher risk of cerebrovascular accidents. It is unknown which factors drive vulnerable plaque development. Shear stress, the frictional force of blood at the vessel wall, is known to influence plaque formation. We evaluated the association between shear stress and plaque components (intraplaque haemorrhage (IPH), lipid rich necrotic core (LRNC) and/or calcifications) in relatively small carotid artery plaques in asymptomatic persons. METHODS: Participants (n = 74) from the population-based Rotterdam Study, all with carotid atherosclerosis assessed on ultrasound, underwent carotid MRI. Multiple MRI sequences were used to evaluate the presence of IPH, LRNC and/or calcifications in plaques in the carotid arteries. Images were automatically segmented for lumen and outer wall to obtain a 3D reconstruction of the carotid bifurcation. These reconstructions were used to calculate minimum, mean and maximum shear stresses by applying computational fluid dynamics with subject-specific inflow conditions. Associations between shear stress measures and plaque composition were studied using generalized estimating equations analysis, adjusting for age, sex and carotid wall thickness. RESULTS: The study group consisted of 93 atherosclerotic carotid arteries of 74 participants. In plaques with higher maximum shear stresses, IPH was more often present (OR per unit increase in maximum shear stress (log transformed) = 12.14; p = 0.001). Higher maximum shear stress was also significantly associated with the presence of calcifications (OR = 4.28; p = 0.015). CONCLUSIONS: Higher maximum shear stress is associated with intraplaque haemorrhage and calcifications.


Assuntos
Artérias Carótidas/patologia , Placa Aterosclerótica/complicações , Resistência ao Cisalhamento , Idoso , Pressão Sanguínea , Artérias Carótidas/química , Doenças das Artérias Carótidas/complicações , Doenças das Artérias Carótidas/diagnóstico por imagem , Estenose das Carótidas/complicações , Estenose das Carótidas/diagnóstico por imagem , Feminino , Hemorragia/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Placa Aterosclerótica/diagnóstico por imagem , Estudos Prospectivos , Estresse Mecânico
15.
AJNR Am J Neuroradiol ; 36(11): 2127-33, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26251429

RESUMO

BACKGROUND AND PURPOSE: An important characteristic of vulnerable plaque, intraplaque hemorrhage, may predict plaque rupture. Plaque rupture can be visible on noninvasive imaging as a disruption of the plaque surface. We investigated the association between intraplaque hemorrhage and disruption of the plaque surface. MATERIALS AND METHODS: We selected the first 100 patients of the Plaque At RISK study, an ongoing prospective noninvasive plaque imaging study in patients with mild-to-moderate atherosclerotic lesions in the carotid artery. In carotid artery plaques, disruption of the plaque surface (defined as ulcerated plaques and/or fissured fibrous cap) and intraplaque hemorrhage were assessed by using MDCTA and 3T MR imaging, respectively. We used a χ(2) test and multivariable logistic regression to assess the association between intraplaque hemorrhage and disrupted plaque surface. RESULTS: One hundred forty-nine carotid arteries in 78 patients could be used for the current analyses. Intraplaque hemorrhage and plaque ulcerations were more prevalent in symptomatic compared with contralateral vessels (hemorrhage, 38% versus 11%; P < .001; and ulcerations, 27% versus 7%; P = .001). Fissured fibrous cap was more prevalent in symptomatic compared with contralateral vessels (13% versus 4%; P = .06). After adjustment for age, sex, diabetes mellitus, and degree of stenosis, intraplaque hemorrhage was associated with disrupted plaque surface (OR, 3.13; 95% CI, 1.25-7.84) in all vessels. CONCLUSIONS: Intraplaque hemorrhage is associated with disruption of the plaque surface in patients with a carotid artery stenosis of <70%. Serial studies are needed to investigate whether intraplaque hemorrhage indeed increases the risk of plaque rupture and subsequent ischemic stroke during follow-up.


Assuntos
Estenose das Carótidas/patologia , Diagnóstico por Imagem , Hemorragia/patologia , Placa Aterosclerótica/patologia , Idoso , Artérias Carótidas/patologia , Feminino , Hemorragia/epidemiologia , Humanos , Interpretação de Imagem Assistida por Computador , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , Fatores de Risco , Acidente Vascular Cerebral/etiologia
16.
Med Eng Phys ; 37(8): 801-7, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26130603

RESUMO

The material properties of atherosclerotic plaques govern the biomechanical environment, which is associated with rupture-risk. We investigated the feasibility of noninvasively estimating carotid plaque component material properties through simulating ultrasound (US) elastography and in vivo magnetic resonance imaging (MRI), and solving the inverse problem with finite element analysis. 2D plaque models were derived from endarterectomy specimens of nine patients. Nonlinear neo-Hookean models (tissue elasticity C1) were assigned to fibrous intima, wall (i.e., media/adventitia), and lipid-rich necrotic core. Finite element analysis was used to simulate clinical cross-sectional US strain imaging. Computer-simulated, single-slice in vivo MR images were segmented by two MR readers. We investigated multiple scenarios for plaque model elasticity, and consistently found clear separations between estimated tissue elasticity values. The intima C1 (160 kPa scenario) was estimated as 125.8 ± 19.4 kPa (reader 1) and 128.9 ± 24.8 kPa (reader 2). The lipid-rich necrotic core C1 (5 kPa) was estimated as 5.6 ± 2.0 kPa (reader 1) and 8.5 ± 4.5 kPa (reader 2). A scenario with a stiffer wall yielded similar results, while realistic US strain noise and rotating the models had little influence, thus demonstrating robustness of the procedure. The promising findings of this computer-simulation study stimulate applying the proposed methodology in a clinical setting.


Assuntos
Doenças das Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/patologia , Técnicas de Imagem por Elasticidade/métodos , Imageamento por Ressonância Magnética/métodos , Placa Aterosclerótica/diagnóstico por imagem , Placa Aterosclerótica/patologia , Simulação por Computador , Estudos de Viabilidade , Análise de Elementos Finitos , Humanos , Modelos Cardiovasculares , Dinâmica não Linear
17.
BJOG ; 122(7): 1022-30, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25754458

RESUMO

OBJECTIVE: To compare transvaginal prolapse repair combined with midurethral sling (MUS) versus prolapse repair only. DESIGN: Multi-centre randomised trial. SETTING: Fourteen teaching hospitals in the Netherlands. POPULATION: Women with symptomatic stage two or greater pelvic organ prolapse (POP), and subjective or objective stress urinary incontinence (SUI) without prolapse reduction. METHODS: Women were randomly assigned to undergo vaginal prolapse repair with or without MUS. Analysis was according to intention to treat. MAIN OUTCOME MEASURES: The primary outcome at 12 months' follow-up was the absence of urinary incontinence (UI) assessed with the Urogenital Distress Inventory and treatment for SUI or overactive bladder. Secondary outcomes included complications. RESULTS: One hundred and thirty-four women were analysed at 12 months' follow-up (63 in MUS and 71 in control group). More women in the MUS group reported the absence of UI and SUI; respectively 62% versus 30% UI (relative risk [RR] 2.09; 95% confidence interval [CI] 1.39-3.15) and 78% versus 39% SUI (RR 1.97; 95% CI 1.44-2.71). Fewer women underwent treatment for postoperative SUI in the MUS group (10% versus 37%; RR 0.26; 95% CI 0.11-0.59). In the control group, 12 women (17%) underwent MUS after prolapse surgery versus none in the MUS group. Severe complications were more common in the MUS group, but the difference was not statistically significant (16% versus 6%; RR 2.82; 95% CI 0.93-8.54). CONCLUSIONS: Women with prolapse and co-existing SUI are less likely to have SUI after transvaginal prolapse repair with MUS compared with prolapse repair only. However, only 17% of the women undergoing POP surgery needed additional MUS. A well-informed decision balancing risks and benefits of both strategies should be tailored to individual women.


Assuntos
Procedimentos Cirúrgicos em Ginecologia/métodos , Prolapso de Órgão Pélvico/cirurgia , Slings Suburetrais/estatística & dados numéricos , Incontinência Urinária por Estresse/cirurgia , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Países Baixos , Inquéritos e Questionários , Resultado do Tratamento , Bexiga Urinária Hiperativa/prevenção & controle
18.
Biotechnol Bioeng ; 112(1): 220-7, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25088405

RESUMO

The use of stem cells for the repair of damaged cardiac tissue after a myocardial infarction holds great promise. However, a common finding in experimental studies is the low number of cells delivered at the area at risk. To improve the delivery, we are currently investigating a novel delivery platform in which stem cells are conjugated with targeted microbubbles, creating echogenic complexes dubbed StemBells. These StemBells vibrate in response to incoming ultrasound waves making them susceptible to acoustic radiation force. The acoustic force can then be employed to propel circulating StemBells from the centerline of the vessel to the wall, facilitating localized stem cell delivery. In this study, we investigate the feasibility of manipulating StemBells acoustically in vivo after injection using a chicken embryo model. Bare stem cells or unsaturated stem cells (<5 bubbles/cell) do not respond to ultrasound application (1 MHz, peak negative acoustical pressure P_ = 200 kPa, 10% duty cycle). However, stem cells which are fully saturated with targeted microbubbles (>30 bubbles/cell) can be propelled toward and arrested at the vessel wall. The mean translational velocities measured are 61 and 177 µm/s for P- = 200 and 450 kPa, respectively. This technique therefore offers potential for enhanced and well-controlled stem cell delivery for improved cardiac repair after a myocardial infarction.


Assuntos
Transplante de Células-Tronco Mesenquimais , Microbolhas , Microscopia/métodos , Células-Tronco/citologia , Acústica , Animais , Células Cultivadas , Embrião de Galinha , Galinhas , Humanos
19.
Ultraschall Med ; 36(2): 154-61, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24824762

RESUMO

PURPOSE: Intraplaque neovascularization (IPN) is an increasingly studied marker of the vulnerable atherosclerotic plaque, and contrast-enhanced ultrasound (CEUS) is an in vivo imaging technique for the assessment of IPN. The purpose of this study was to test novel quantification methods for the detection of carotid IPN using CEUS. MATERIALS AND METHODS: 25 patients with established carotid atherosclerosis underwent bilateral carotid CEUS using a Philips iU-22 ultrasound system with an L9 - 3 transducer. Visual scoring of IPN was performed using a 3-point score. Quantification of IPN was performed using novel custom developed software. In short, regions of interest were drawn over the atherosclerotic plaques. After motion compensation, several IPN features were calculated. Statistical analysis was performed using Spearman's rho. Reproducibility of the quantification features was calculated using intra-class correlation coefficients and mean differences between calculations. RESULTS: 45 carotid arteries were available for the quantification of IPN. The quantification of IPN was feasible in all 45 carotid plaques. The IPN area, IPN area ratio and neovessel count had a good correlation with the visual IPN score (respectively ρ = 0.719, ρ = 0.538, ρ = 0.474 all p < 0.01). The intra-observer and inter-observer agreement was good to excellent (p < 0.01). The intra-observer and inter-observer variability was low. CONCLUSION: The quantification of carotid IPN on CEUS is feasible and provides multiple features on carotid IPN. Accurate quantitative assessment of IPN may be important to recognize and to monitor changes during therapy in vulnerable atherosclerotic plaques.


Assuntos
Artéria Carótida Interna/diagnóstico por imagem , Estenose das Carótidas/diagnóstico por imagem , Meios de Contraste , Aumento da Imagem , Interpretação de Imagem Assistida por Computador , Neovascularização Patológica/diagnóstico por imagem , Software , Idoso , Estudos de Viabilidade , Feminino , Humanos , Ataque Isquêmico Transitório/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Ultrassonografia
20.
Ultrasound Int Open ; 1(2): E67-71, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27689156

RESUMO

AIM: The actual occurrence of spontaneous plaque rupture in mice has been a matter of debate. We report on an in vivo observation of the actual event of possible plaque disruption in a living ApoE(-/-) mouse. METHODS AND RESULTS: During live contrast-enhanced ultrasonography of a 50-week-old ApoE(-/-) male mouse, symptoms suggesting plaque disruption in the brachiocephalic artery were observed. Histological analysis confirmed the presence of advanced atherosclerotic lesions with dissections and intraplaque hemorrhage in the affected brachiocephalic trunk, pointing towards plaque rupture as the cause of the observed event. However, we did not detect a luminal thrombus or cap rupture, which is a key criterion for plaque rupture in human atherosclerosis. CONCLUSION: This study reports the real-time occurrence of a possible plaque rupture in a living ApoE(-/-) mouse.

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