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Plaque Area (plaque + area)
Selected AbstractsExtraction of media and plaque boundaries in intravascular ultrasound images by level sets and min/max flowEXPERT SYSTEMS, Issue 2 2010Ali Iskurt Abstract: Estimation of the plaque area in intravascular ultrasound images after extraction of the media and plaque,lumen interfaces is an important application of computer-aided diagnosis in medical imaging. This paper presents a novel system for fully automatic and fast calculation of plaque quantity by capturing the surrounding ring called media. The system utilizes an algorithm that consists of an enhanced technique for noise removal and a method of detecting different iso levels by sinking the image gradually under zero level. Moreover, an important novelty with this technique is the simultaneous extraction of media and lumen,plaque interfaces at satisfactory levels. There are no higher dimensional surfaces and evolution of contours, stopping at high image gradients. Thus, the system runs really fast with curvature velocity only and has no complexity. Experiments also show that this shape-recovering curvature term not only removes the noisy behaviour of ultrasound images but also strengthens very weak boundaries and even completes the missing walls of the media. In addition, the lumen,plaque interface can be detected simultaneously. For validation, a new and very useful algorithm is developed for labelling of intravascular ultrasound images, taken from video sequences of 15 patients, and a comparison-based verification is done between manual contours by experts and the contours extracted by our system. [source] High dietary methionine plus cholesterol stimulates early atherosclerosis and late fibrous cap development which is associated with a decrease in GRP78 positive plaque cellsINTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 3 2009Anthony Zulli Summary The role of homocysteine, or its precursor methionine, in the formation of fibrous caps and its association with endoplasmic reticulum (ER) stress is unclear. Homocysteine can stimulate collagen accumulation and upregulate the ER stress chaperone glucose regulated protein 78 (GRP78). The aim of this study was to determine if high dietary methionine would increase fibrous caps, and that removal of an atherogenic diet would decrease the amount of ER stressed cells. New Zealand white rabbits were fed for 2, 4, or 12 weeks an atherogenic diet [1% methionine + 0.5% cholesterol (2MC, 4MC or 12MC)]; for 4 or 12 weeks a 0.5% cholesterol diet (4Ch, 12Ch); and to study plaque regression, an MC diet for 2 or 4 weeks accompanied by 10 weeks of a normal diet (2MCr, 4MCr). Endothelial function, atherosclerosis and GRP78 positive cells were studied. Endothelial function was abolished in 4MC and atherosclerosis increased 17-fold (P < 0.05) compared with 4Ch. Fibrous caps composed 48% of total plaque area in 12MC vs. 10% in 12Ch (P < 0.01), and 12MC expressed less GRP78 plaque cells vs. 12Ch (P < 0.01). Four MCr had less plaque GRP78 cells than 12MC (P < 0.05) and less endothelial GRP78 cells (P < 0.01). In addition, GRP78 positive cells were the highest in 4MC, but decreased in all other groups (P < 0.01). GRP78 positive cells within the fibrous cap inversely correlated with cap size (r2 = 0.9). These studies suggest that high dietary methionine could be beneficial for plaque stabilisation, and a normal diet also stabilises plaque and decreases the number of stressed plaque cells. [source] A study into the plaque-inhibitory activity of experimental toothpaste formulations containing antimicrobial agentsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 8 2005J. Moran Abstract Background/Aims: The use of specific antimicrobial agents in toothpastes may help reduce plaque and gingivitis. There would also appear to be some value in formulating products that contain combinations of such agents that may potentiate any activity present. The aims of this exploratory and pragmatic study were twofold:- (1) exploratory: to compare the effects on plaque re-growth of two zinc citrate/triclosan formulations, one of which contained bromochlorophene and hence demonstrate any additional beneficial effects produced by the addition of the phenol. (2) pragmatic: to assess whether both pastes were significantly better than a benchmark control, proprietary fluoride toothpaste at inhibiting plaque formation. Methods: Following an initial prophylaxis to remove all plaque and calculus, toothpaste slurry rinses were used over a 96 h period by 24 volunteers, while omitting all other oral hygiene procedures. After 24, 48 and 96 h, plaque was measured by plaque area and by plaque index. For comparative purposes, a conventional commercial fluoride toothpaste rinse was also used as a benchmark control in this triple cross-over double-blind study. Results: With one exception, comparisons between the three pastes failed to show any significant differences in plaque accumulation at 96 h whether assessed by plaque index or area. At this time period, significantly more plaque was seen with the zinc citrate paste without bromochlorophene, compared with that of the control paste. Conclusions: The findings from this study failed to demonstrate a plaque-inhibitory action from the two novel formulations beyond that of a conventional benchmark toothpaste, although overall levels of plaque formed by the volunteers, especially on the control paste were generally lower than in previous studies. Nevertheless, it remains to be determined whether the test formulations could exert a direct anti-inflammatory action against gingivitis by way of the triclosan delivery system. Neither test formulation was subsequently marketed. [source] Effect of an amine-fluoride-triclosan mouthrinse on plaque regrowth and biofilm vitalityJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 4 2002Nicole B. Arweiler Abstract Background: The purpose of this double-blind, prospective, latin-square crossover randomised study was to examine the efficacy of a mouthrinse solution containing a combination of triclosan, amine fluoride and sodium fluoride on supragingival plaque regrowth compared to a placebo and a chlorhexidine solution. Methods: 12 volunteers refrained after professional oral prophylaxis from all mechanical hygiene measures for the following 96 h and rinsed instead cross-over in a randomised order with either chlorhexidine dicluconate (0.2%, positive control), a verum solution (0.5% amine fluoride, 0.028% sodium fluoride, 0.03% triclosan) or a placebo solution. The plaque index was assessed after 24 and 96 h (PI 1, PI 2) and the plaque area (PA) photographed and calculated after 96 h of undisturbed plaque regrowth. Moreover plaque samples were taken after 24 and 96 h and examined with the vital fluorescence technique to assess the vitality of the biofilm microbiota (VF 1, VF 2). Results: The amine-fluoride-triclosan solution reduced the clinical parameters (PI and PA) as well as the vitality of the plaque flora (VF) significantly when compared to the placebo solution. The verum reached a 36.5% (p<0.05) and a 39.8% reduction (p<0.0001) in PI 1 and PI 2, respectively, concomittant with a reduction of 23.8% and 32.2% (p<0.001) in VF 1 and VF 2 and of 46.9% (p<0.0001) in PA at day 4. This was less than the reductions found with the positive control, i.e., the 0.2% chlorhexidine solution (54.2% and 71.1% reduction in PI 1 and PI 2, 40.0% and 53.4% in VF 1 and VF 2 and 71.5% in PA). However, significant differences between both active solutions were only established for PI 2 and PA. Conclusion: During 4-day plaque regrowth the amine-fluoride-triclosan product displayed a significant antibacterial and plaque-reducing action in comparison to the control. Zusammenfassung Hintergrund: Der Zweck dieser prospektiven, gekreuzten, randomisierten Doppeltblindstudie war die Überprüfung der Effektivität einer Mundspüllösung, die eine Kombination von Triclosan, Aminfluorid und Natriumfluorid enthielt, auf die Neuetablierung der supragingivalen Plaque im Vergleich zu einem Placebo und einer Chlorhexidinlösung. Methoden: 12 Probanden wurde nach einer professionellen Prophylaxe jegliche mechanische Hygiene für die folgenden 96 Stunden untersagt. Sie spülten dafür überkreuzt in einer zufälligen Reihenfolge entweder mit Chlorhexidindiglukonat (0.2%, positive Kontrolle), einer Versuchslösung (0.5% Aminfluorid, 0.028% Natriumfluorid, 0.03% Triclosan) oder einer Placebolösung. Der Plaque-index wurde nach 24 Stunden und 96 Stunden erhoben (PI 1, PI 2). Die Plaquefläche (PA) wurde fotografiert und berechnet nach 96 Stunden des ungestörten Plaquewachstums. Zusätzlich wurden Plaqueproben nach 24 und 96 Stunden entnommen und mit der Vitalfluoreszenztechnik die Vitalität der Mikroflora des Biofilms bestimmt (VF 1, VF 2). Ergebnisse: Die Aminfluorid-Triclosan-Lösung reduzierte die klinischen Parameter (PI und PA) sowie die Vitalität der Plaqueflora (VF) signifikant, im Vergleich mit der Placebolösung. Die Versuchslösung erreichte eine 36.5%ige (p<0.05) und eine 39.8%ige Reduktion (p<0.001) bei PI 1 und PI 2, verbunden mit einer Reduktion von 23.8% und 32.2% (p<0.01) bei VF 1 und VF 2 und 46.9% (p<0.0001) bei PA am Tag 4. Dies war geringer als die Reduktionen, die mit der positiven Kontrolle gefunden wurden, d.h. mit der 0.2%igen Chlorhexidin-Lösung (54.2% und 71.1% Reduktion bei PI 1 und PI 2, 40.0% und 53.4% bei VF 1 und VF 2 sowie 71.5% bei PA). Jedoch wurden signifikante Differenzen zwischen beiden aktiven Lösungen nur bei PI 2 und PA gefunden. Zusammenfassung: Während eines 4tägigen Plaquewachstums zeigte das Aminfluorid-Triclosan-Produkt eine signifikante antibakterielle und plaquereduzierende Wirkung im Vergleich zu der Kontrolle. Résumé Origine: Le but de cette étude randomisée, croisée, prospective en double aveugle a été d'examiner l'efficacité d'une solution contenant une association de fluorure d'amine, de fluorure de sodium et de triclosan sur l'accumulation de la plaque dentaire sus-gingivale comparée à un placebo et à une solution de chlorhexidine (CHX). Méthodes: Après un nettoyage professionnel, 12 volontaires ont arrêté toutes mesures d'hygiène buccale pendant 96 h. Ils se sont rinçés de manière randomisée et croisée avec du digluconate de CHX 0.2%, une solution verum (fluorure d'amine 0.5%, fluorure de sodium 0.028% et triclosan 0.03%) ou une solution placebo. L'indice de plaque a été mesurée après 24 h (Pli 1) et 96 h (Pli 2) et la zone de plaque (PA) photographiée et calculée après 96 h. Des échantillons de plaque dentaire ont été prélevés après 24 h (VF 1) et 96 h (VF 2) et examinés par la technique de vitalité de fluorescence, pour mesurer la vitalité de la flore du biofilm. Résultats: La solution flurorure d'amine/triclosan réduisait significativement les paramètres cliniques (Pli et PA) ainsi que la vitalité de la flore (VF) comparée à la solution placebo. Le vérum atteignait des réductions respectives de 37% (p<0.05) et 40% (p<0.0001) des Pli 1 et Pli 2 concomitantes avec une réduction de 24 et 32% (p<0.001) de VF 1 et VF 2 et de 47% (p<0.0001) de PA au jour 4. Ceci était inférieur aux réductions trouvées dans le contrôle positif, c.-à-d. la CHX 0.2% (54 et 71% de réduction de Pli 1 et Pli 2, 40 et 53% de VF 1 et VF 2, et 72% de PA). Cependant, les différences significatives entre les deux solutions actives ont été mises en évidence uniquement pour Pli2 et PA. Conclusion: Durant cette courte croissance de la plaque dentaire, le produit fluorure d'amine/triclosan montrait une action antibactérienne et anti-plaque supérieure à celle du contrôle. [source] A study to assess the plaque inhibitory action of a newly formulated triclosan toothpasteJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 1 2001J. Moran Abstract Background/aims: Triclosan containing toothpastes have been noted for their potential to inhibit plaque and gingival inflammation. The aim of this study was to determine whether a toothpaste containing triclosan and an enhanced fluoride system would inhibit de novo plaque formation beyond that of a non-triclosan, conventional fluoride toothpaste. Methods: This study used a 4-day plaque regrowth model in which 24 volunteers used toothpaste rinses as the only form of oral hygiene. Following a prophylaxis and a single brushing with the toothpastes, 2× daily rinsing with toothpaste slurries was used over the following 96 h. Results: After 24 h, there was no difference in plaque area between the triclosan paste and its control paste. After 96 h, a reduction in plaque score of 5% was noted for the test toothpaste compared to the control paste which was statistically significant (p=0.028). For plaque area this reduction was increased to 16%, which was also significant (p=0.006). Conclusions: These findings would appear to warrant further investigation into the potential value of the paste in inhibiting both plaque and gingivitis. [source] Mechanisms of Late Stent Malapposition After Primary Stenting in ST-Elevation Myocardial Infarction: A Subanalysis of the Selection TrialJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 3 2009TANIA CHECHI M.D. Background: One of the major predictors of late stent malapposition (LSM) is primary stenting in acute myocardial infarction. However, mechanisms of LSM are still under debate. Methods: Patients with ST-elevation myocardial infarction (STEMI) and enrolled in the SELECTION trial (38 patients in the paclitaxel-eluting stent, PES, and 35 in the bare metal stent, BMS, cohort) were retrospectively analyzed to evaluate LSM, by means of intravascular ultrasound (IVUS) data recorded at the index and 7-month follow-up procedures. Results: Stent malapposition was documented in 21 lesions in 21 patients (28.8%): in 8 of these 21 patients (38.1%) it was LSM. Although statistical significance was not reached, LSM was more frequent after PES than BMS implantation (15.8% vs. 5.7%). LSM was mainly located within the body of the stent (62.5% of the cases). At the LSM segment, a significant increase of vessel area (19.2 ± 3.3 mm2 vs. 21.9 ± 5.3 mm2, P = 0.04) and a reduction of plaque area (12.6 ± 4.6 mm2 vs. 9.1 ± 3.9 mm2, P = 0.04) were observed at IVUS between the index and follow-up procedure. Conclusions: After primary stenting for STEMI, LSM seems to be more frequent after PES rather than BMS implantation. In the STEMI setting, possible mechanisms leading to LSM include positive remodeling and plaque mass decrease. [source] In vivo detection of hemorrhage in human atherosclerotic plaques with magnetic resonance imaging,JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 1 2004Vincent C. Cappendijk MD Abstract Purpose To investigate the performance of high-resolution T1-weighted (T1w) turbo field echo (TFE) magnetic resonance imaging (MRI) for the identification of the high-risk component intraplaque hemorrhage, which is described in the literature as a troublesome component to detect. Materials and Methods An MRI scan was performed preoperatively on 11 patients who underwent carotid endarterectomy because of symptomatic carotid disease with a stenosis larger than 70%. A commonly used double inversion recovery (DIR) T1w turbo spin echo (TSE) served as the T1w control for the T1w TFE pulse sequence. The MR images were matched slice by slice with histology, and the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the MR images were calculated. Additionally, two readers, who were blinded for the histological results, independently assessed the MR slices concerning the presence of intraplaque hemorrhage. Results More than 80% of the histological proven intraplaque hemorrhage could be detected using the TFE sequence with a high interobserver agreement (Kappa = 0.73). The TFE sequence proved to be superior to the TSE sequence concerning SNR and CNR, but also in the qualitative detection of intraplaque hemorrhage. The false positive TFE results contained fibrous tissue and were all located outside the main plaque area. Conclusion The present study shows that in vivo high-resolution T1w TFE MRI can identify the high-risk component intraplaque hemorrhage with a high detection rate in patients with symptomatic carotid disease. Larger clinical trials are warranted to investigate whether this technique can identify patients at risk for an ischemic attack. J. Magn. Reson. Imaging 2004;20:105,110. © 2004 Wiley-Liss, Inc. [source] Point/Counterpoint: The Role of Carotid UltrasoundPREVENTIVE CARDIOLOGY, Issue 2 2005Point: Uses Of Carotid Plaque Measurement As A Predictor Of Cardiovascular Events Vascular prevention is most cost-effective in high-risk patients, but secondary prevention misses many opportunities. The high-risk strategy-identifying patients with high levels of risk factors-is problematic because traditional risk factors predict only half of vascular events. In multiple regression, traditional risk factors explained only half of carotid atherosclerosis. New strategies are being explored, such as electron-beam computerized tomographic measurement of coronary calcification, to identify high-risk patients. Carotid plaque is a powerful tool for identifying and managing high-risk vascular patients, as it explains twice as much of unexplained vascular risk as coronary calcium by electron beam computerized tomography, and it has significant advantages compared with intimal-medial thickness. After adjustment for risk factors, patients in the highest quartile of baseline plaque area have 3.5 times the risk of stroke, death, or myocardial infarction compared with those in the lowest quartile. Those with regression or stable plaque have half the risk of those with progression after adjustment for the same panel of risk factors. The therapeutic target is plaque regression or stabilization, not just control of traditional risk factors. Trying to treat arteries without measuring plaque is like trying to treat hypertension without measuring the pressure, or hyperlipidemia without measuring the lipids. [source] Association between intraplaque haemorrhage in the carotid atherosclerotic lesion, the degree of internal carotid artery stenosis and timing of ischaemic neurological eventsBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 4 2001R. Mofidi Background: Expansion of carotid atherosclerotic plaques as a result of intraplaque haemorrhage has been implicated in the development of ischaemic neurological events. The relationship between the quantity of haemorrhage in the dominant atherosclerotic lesion, the degree of internal carotid artery (ICA) stenosis and the chronology of patients' symptoms was examined. Methods: Consecutive patients undergoing carotid endarterectomy were included. The nature and timing of symptoms were recorded. Aortic arch injection digital subtraction angiography was performed before operation. Carotid endarterectomy specimens were serially sectioned and examined histologically. The amount of intraplaque haemorrhage was measured with digital image analysis. The influence of timing of symptoms on the quantity of intraplaque haemorrhage was compared with Kaplan,Meier analysis. Correlation between degree of ICA stenosis and quantity of intraplaque haemorrhage was assessed by means of regression analysis. Results: Seventy-four patients (20 asymptomatic, 54 symptomatic) were included. The median latency of symptoms was 28 (1,600) days. Intraplaque haemorrhage was common: 54 (73 per cent) of 74 patients. Mean(s.e.m.) cumulative symptom-free survival before operation for patients with no intraplaque haemorrhage was 0·71(0·11), compared with 0·58(0·11) in those exhibiting haemorrhage in less than 50 per cent of the plaque area, and 0·20(0·07) in lesions with over 50 per cent (P = 0·002). A close correlation was observed between the degree of ICA stenosis and haemorrhagic content of the dominant atherosclerotic lesion (r2 = 0·433, P < 0·001). Conclusion: These results confirm the association between intraplaque haemorrhage and the degree of ICA stenosis. They further demonstrate an association between the size of haemorrhage and timing of neurological events, suggesting a causative role for intraplaque haemorrhage in the development of ischaemic neurological events. © 2001 British Journal of Surgery Society Ltd [source] Ultrasonographic measurements of subclinical carotid atherosclerosis in prediction of ischemic strokeACTA NEUROLOGICA SCANDINAVICA, Issue 2009E. B. Mathiesen Carotid intima-media thickness (IMT) and plaque measurements are widely used to quantify atherosclerosis and assess the risk of future stroke, and are used as surrogate endpoints for clinical disease. In recent years, it has become clear that carotid IMT and plaque reflect biologically and genetically different aspects of the atherosclerotic process, and are differentially related to risk factors and cardiovascular disease. Plaques are focal manifestations of atherosclerosis while increased IMT represents mainly hypertensive medial hypertrophy. Several prospective studies have showed that IMT and plaque measurements, such as total plaque area and plaque number, are predictive of future stroke. Plaque echogenicity predicts future stroke independent of plaque size. The contribution of IMT and plaque measurements in individual stroke risk prediction in the general population seems to be limited, but may be useful as a tool for individual stratification of high-risk patients. [source] Evaluation of accuracy and variability of scoring-area-based plaque indicesJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 1 2000A laboratory model Abstract Background: Plaque scoring, using a variety of indices and methods, is widely used in clinical dentistry. There is limited information on inter- and intra-examiner variability and almost no data on examiner accuracy. Aims: The aim of this study, was to determine the inter- and intra-examiner variability and accuracy of 15 examiners, of differing plaque-scoring experience, in recording and judging plaque areas from simulated plaque on tooth charts. Methods: Plaque, shaded red, was drawn onto tooth charts of 8 simulated "patients" and measured by planimetry by 1 investigator. For each tooth for each "patient", examiners subjectively copied the plaque onto blank charts and scored plaque in 5% increments for the global plaque index. This was repeated on 2 occasions. Drawn plaque areas were determine by the investigator and comparisons made with the actual areas and % scores of plaque. Results: For both plaque recording methods, intra-examiner variability was low and slighly better than inter-examiner variability. Reproducing plaque areas showed a high level of accuracy in most examiners, as was judging areas in 5% increments, albeit slightly less accurate than area drawing. Overall examiner experience had little influence on judging plaque areas. Conclusion: The data suggest that area-based plaque indices can be scored or recorded accurately and with minimal variability within or between examiners. The laboratory model could be used to train and assess examiners. [source] Efficacy and Safety of Absorbable Metallic Stents with Adjunct Intracoronary Beta Radiation in Porcine Coronary ArteriesJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 5 2007F.A.C.C., RON WAKSMAN M.D. Background: Absorbable metallic stents (AMS) utilizing Mg alloy carry advantages over permanent metallic stents because of their potential to eliminate stent thrombosis, chronic inflammation, or artifacts with noninvasive imaging. These stents, however, are associated with a modest degree of late recoil and intimal hyperplasia. The aim of the study was to test whether adjunct vascular brachytherapy (VBT) compared to AMS alone can overcome these limitations. Methods: Juvenile domestic pig coronary arteries underwent implantation of either AMS (n = 11) with prior adjunct VBT utilizing Sr/Y-90 , source seeds, with a dose of 24 Gy at 2 mm from the source, or AMS alone (n = 11). At 28 days following intravascular ultrasound, vessels were harvested and analyzed by histomorphometry. Results: Intravascular ultrasound analysis indicated that at follow-up, though statistically not significant, lumen and stent areas in the segments deployed with AMS following radiation were larger than those deployed with AMS alone (3.94 ± 1.38 and 3.53 ± 1.75 vs. 2.99 ± 1.05 and 3.58 ± 1.48). Extrastent plaque and intrastent plaque areas in the same segments were smaller (2.76 ± 0.82 and 0.24 ± 0.47 vs. 3.25 ± 1.94 and 0.58 ± 0.81). Morphometric data indicate that vessels in the VBT + AMS group showed characteristics of delayed healing and re-endothelialization. Neointimal area was significantly lower in the VBT + AMS group (0.49 ± 0.34) compared to AMS (1.3 ± 0.62, P = 0.001). Lumen area of the VBT + AMS was larger when compared with AMS alone (2.49 ± 0.82 vs. 1.75 ± 0.51, P = 0.02). Conclusion: VBT as an adjunct to AMS further reduces the intimal hyperplasia and improves the lumen area when compared to AMS alone but does not have any impact on late recoil. [source] | ||||||||||