Plaque Visualization Research Articles

Impact of visual presentation of atherosclerotic carotid plaque on cardiovascular risk profile using mHealth technologies

This randomized, controlled trial evaluated the impact of plaque visualization combined with daily tasks on cardiovascular risk profile and included 240 participants with coronary arterial disease. The intervention group received the PreventiPlaque app during the 12-month study period in addition to standard care. The app contained daily tasks that promoted lifestyle modifications and adherence to prescribed medication. It included ultrasound images of participants´ individual carotid plaque, which were updated regularly. The impact of plaque visualization and personalized app usage was evaluated, using a change in the SCORE2 as a primary endpoint. In the intervention group, the SCORE2 was significantly lower after the study period (t(120) = 6.43, padj < 0.001, dRM = 0.58). This demonstrates the efficacy of the PreventiPlaque app in supporting lifestyle modifications and medication adherence. These findings suggest that personalized mHealth interventions in combination with visual risk communication are valuable tools in secondary prevention. Trial Registration: The study was registered at ClinicalTrials.gov under the identifier NCT05096637 on 27 October 2021 and was approved by the local ethics committee of the University of Duisburg-Essen (20-9157-BO).

Comparison of the Short Time Effect of an Oral Hygiene Education in Four Sessions via Quantitative Light-Induced Fluorescence Technology Versus Disclosing Agents in Children: A Randomized, Crossover Clinical Trial.

The aim of this study is to compare the effectiveness of Qscan plus™ (AIOBIO, Seoul, Korea) based on quantitative light-induced fluorescence (QLF) technology and disclosing agents in oral health programs in children. A randomized crossover study was conducted for Korean children aged 6-11 years. Fifty-eight participants (29 to use Qscan plus™ first and 29 to use the disclosing agent first) were enrolled in this study. The participants were randomly divided into two groups. One group was assigned to brush with Qscan plus™, while the other group brushed with disclosed plaque visualization. One month later, the groups switched procedures. A total of 39 participants were analyzed, excluding those lost during the trial. There was no adverse event during the trial. The patient hygiene performance (PHP) index was used to assess oral hygiene status, and questionnaires about oral health behavior and attitude were completed. The data were analyzed using repeated-measure analysis of variance, with a significance level of p < 0.05. The PHP score decreased significantly on post-brushing and follow-up compared to baseline in both methods (p < 0.001), but there was no significant difference between the two methods. After oral hygiene education, participants' brushing time increased, and their oral care attitudes improved. More participants preferred the Qscan device to the disclosed plaque visualization because it is more easily noticeable. The Qscan device has a similar educational effect as disclosing agents, and can be used as a supplementary tool to encourage children in oral hygiene education.

Role of imaging techniques in the assessment of vulnerable plaques and the effectiveness of lipid-lowering therapy

The aim was to evaluate the potential of various imaging methods in the diagnosis of vulnerable coronary plaques and their stabilization using various lipid-lowering therapy regimens.The sources were searched in the PubMed database using the following keywords: "vulnerable (unstable) plaque" AND "PCSK9 inhibitors" AND "intravascular ultrasound" OR "optical coherence tomography" OR "computed tomography angiography". As a result, 8 original clinical trials were selected that corresponded to the review purpose. We assessed the results of following studies on plaque imaging and their regression with various lipid-lowering therapy regimens: GLAGVO, ODYSSEY J, PACMAN-AMI, HUYGENS, ALTAIR, ARCHITECT, etc. The results of most studies have established the advantages of a combined regimen of lipid-lowering therapy (statin+PCSK9 inhibitor) in reducing the rate of cardiovascular events in com­parison with statin monotherapy. The reduction in plaque volume ranged from 0,95% to 2,13% in patients receiving a combination of lipid-lowering drugs, while in monotherapy, it increased from 0,05% to 0,92% (GLAGOV, PACMAN-AMI). The changes of minimum fibrous cap thickness varied from 18,0-62,67 µm with combined therapy and 13,2-33,19 µm with monotherapy (PACMAN-AMI, Gao F). Lipid arc regression was 57,5о in combination therapy (statin+PCSK9 inhibitor) and 31,4о in statin monotherapy (HUYGENS). Imaging diagnostic methods makes it possible to identify vulnerable plaques, which helps in consideration of combination lipid-lowering therapy. In addition, plaque visualization makes it possible to evaluate the treatment effectiveness.

Influence of Repeated Plaque Visualization on Cardiovascular Risk Reduction after 3 years; a randomized controlled trial.

Helping people to understand their cardiovascular (CV) risk can influence the choices they make for risk reduction, including medication adherence and lifestyle modification. This study sought whether repeated visualization of coronary artery calcium (CAC) images was effective in sustaining long-term risk control in primary prevention, independent of a risk reduction program. Asymptomatic, statin-naïve participants, 40-70 years, with a family history of premature coronary artery disease and a CAC score from 1-400 were randomised to a nurse-led CV risk reduction program or standard care with bi-annual reviews. Only the intervention group (220 of 449 participants) visualised their CAC image (with repeat exposure in the first 3 months) and were initiated on statin therapy. The primary outcome was change in Framingham Risk Score (FRS) at 36 months, and the impact of CAC image recall on CV risk was assessed. The reduction in FRS (difference in differences (DID): -3.4% [95%CI: -4.4% to -2.4%], p=<0.001 and low-density-lipoprotein-cholesterol -1.2mmol/L [95%CI: -1.4 to -1.0], p=<0.001)) over 36 months was greater in the intervention than the control group. Within the intervention group, sustained recall of CAC images at 24 months was associated with lower systolic blood pressure (DID -4.3mmHg [95%CI: -7.7 to-0.9], p=0.01) and waist circumference (DID -2.0cm [95% CI: -3.9 to -0.1], p=0.03) at 36 months compared to unsustained recall. A nurse-led program, combining personalized patient visualization of CAC imaging with statin therapy, is beneficial for improving CV risk. Recalling the presentation of CAC images through repeated visual exposure may influence risk reduction.

High-field magnetic resonance microscopy of aortic plaques in a mouse model of atherosclerosis

ObjectivesPre-clinical models of human atherosclerosis are extensively used; however, traditional histological methods do not allow for a holistic view of vascular lesions. We describe an ex-vivo, high-resolution MRI method that allows the 3 dimensional imaging of the vessel for aortic plaque visualization and quantification.Materials and methodsAortas from apolipoprotein-E-deficient (apoE−/−) mice fed an atherogenic diet (group 1) or a control diet (group 2) were subjected to 14 T MR imaging using a 3D gradient echo sequence. The obtained data sets were reconstructed (Matlab), segmented, and analyzed (Avizo). The aortas were further sectioned and subjected to traditional histological analysis (Oil-Red O and hematoxylin staining) for comparison.ResultsA resolution up to 15 × 10x10 μm3 revealed that plaque burden (mm3) was significantly (p < 0.05) higher in group 1 (0.41 ± 0.25, n = 4) than in group 2 (0.01 ± 0.01, n = 3). The achieved resolution provided similar detail on the plaque and the vessel wall morphology compared with histology. Digital image segmentation of the aorta's lumen, plaque, and wall offered three-dimensional visualizations of the entire, intact aortas.Discussion14 T MR microscopy provided histology-like details of pathologically relevant vascular lesions. This work may provide the path research needs to take to enable plaque characterization in clinical applications.

Effect of visual presentation of atherosclerotic carotid plaque on adherence to secondary preventive therapy using mHealth technologies (PreventiPlaque app): Study protocol for a randomized controlled trial

BackgroundCardiovascular disease is the major cause of death worldwide. Although knowledge regarding diagnosing and treating cardiovascular disease has increased dramatically, secondary prevention remains insufficiently implemented due to failure among affected individuals to adhere to guideline recommendations. This has continued to lead to high morbidity and mortality rates. Involving patients in their healthcare and facilitating their active roles in their chronic disease management is an opportunity to meet the needs of the increasing number of cardiovascular patients. However, simple recall of advice regarding a more preventive lifestyle does not affect sustainable behavioral lifestyle changes. We investigate the effect of plaque visualization combined with low-threshold daily lifestyle tasks using the smartphone app PreventiPlaque to evaluate change in cardiovascular risk profile. Methodsand study design: This randomized, controlled clinical trial includes 240 participants with ultrasound evidence of atherosclerotic plaque in one or both carotid arteries, defined as focal thickening of the vessel wall measuring 50% more than the regular vessel wall. A criterion for participation is access to a smartphone suitable for app usage. The participants are randomly assigned to an intervention or a control group. While both groups receive the standard of care, the intervention group has additional access to the PreventiPlaque app during the 12-month follow-up. The app includes daily tasks that promote a healthier lifestyle in the areas of smoking cessation, medication adherence, physical activity, and diet. The impact of plaque visualization and app use on the change in cardiovascular risk profile is assessed by SCORE2. Feasibility and effectiveness of the PreventiPlaque app are evaluated using standardized and validated measures for patient feedback. Ethics and disseminationThis clinical trial is approved by the ethics committee of the University of Duisburg-Essen (Germany). Study results will be disseminated at conferences and in peer-reviewed journals. Information regarding the PreventiPlaque app is available via print media, social media channels, and on the authors’ websites.

Preparation of near-infrared AIEgen-active fluorescent probes for mapping amyloid-β plaques in brain tissues and living mice.

Fibrillar aggregates of the amyloid-β protein (Aβ) are the main component of the senile plaques found in brains of patients with Alzheimer's disease (AD). Development of probes allowing the noninvasive and high-fidelity mapping of Aβ plaques in vivo is critical for AD early detection, drug screening and biomedical research. QM-FN-SO3 (quinoline-malononitrile-thiophene-(dimethylamino)phenylsulfonate) is a near-infrared aggregation-induced-emission-active fluorescent probe capable of crossing the blood-brain barrier (BBB) and ultrasensitively lighting up Aβ plaques in living mice. Herein, we describe detailed procedures for the two-stage synthesis of QM-FN-SO3 and its applications for mapping Aβ plaques in brain tissues and living mice. Compared with commercial thioflavin (Th) derivatives ThT and ThS (the gold standard for detection of Aβ aggregates) and other reported Aβ plaque fluorescent probes, QM-FN-SO3 confers several advantages, such as long emission wavelength, large Stokes shift, ultrahigh sensitivity, good BBB penetrability and miscibility in aqueous biological media. The preparation of QM-FN-SO3 takes ~2 d, and the confocal imaging experiments for Aβ plaque visualization, including the preparation for mouse brain sections, take ~7 d. Notably, acquisition and analyses for in vivo visualization of Aβ plaques in mice can be completed within 1 h and require only a basic knowledge of spectroscopy and chemistry.

In vitro susceptibility of eighteen clinical isolates of human monkeypox virus to tecovirimat.

In 2022, an outbreak of mpox that started in European countries spread worldwide through human-to-human transmission. Cases have been mostly mild, but severe clinical presentations have been reported. In these cases, tecovirimat has been the drug of choice to treat patients with aggravated disease. Here we investigated the tecovirimat susceptibility of 18 clinical isolates of monkeypox virus (MPXV) obtained from different regions of Brazil. Different concentrations of tecovirimat were added to cell monolayers infected with each MPXV isolate. After 72 hours, cells were fixed and stained for plaque visualization, counting, and measurement. The ortholog of F13L gene from each MPXV isolate was polymerase chain reaction (PCR)-amplified, sequenced, and the predicted protein sequences were analyzed. The eighteen MPXV isolates generated plaques of different sizes. Although all isolates were highly sensitive to the drug, two showed different response curves and IC50 values. However, the target protein of tecovirimat, F13 (VP37), was 100% conserved in all MPXV isolates and therefore does not explain the difference in sensitivity. Our results support screening different MPXV isolates for tecovirimat susceptibility as an important tool to better use of the restricted number of tecovirimat doses available in low-income countries to treat patients with mpox.

Diagnosis of Atherosclerotic Plaques Using Vascular Endothelial Growth Factor Receptor-2 Targeting Antibody Nano-microbubble as Ultrasound Contrast Agent.

The atherosclerotic plaque is characterized by narrowing of blood vessels and reduced blood flow leading to the insufficient blood supply to the brain. The hemodynamic changes caused by arterial stenosis increase the shearing force of the fibrous cap on the surface of the plaque, thereby reducing the stability of the plaque. Unstable plaques are more likely to promote angiogenesis and increase the risk of patients with cerebrovascular diseases. A timely understanding of the formation and stability of the arterial plaque can guide in taking targeted measures for reducing the risk of acute stroke in patients. It has been confirmed that nano-microbubbles can enter these plaques through the gaps in the patient's vascular endothelial cells, thereby enhancing the acquisition of ultrasound information for plaque visualization. Therefore, we aim to investigate the diagnostic value of targeted nano-microbubbles for atherosclerotic plaques. This study constructed vascular endothelial growth factor receptor-2 (VEGFR-2) targeting antibody nano-microbubbles and compared its diagnostic value with that of blank nano-microbubbles for atherosclerotic plaques. Studies have found that VEGFR-2 targeting antibody nano-microbubbles can accurately detect the position of plaques. Its detection rate, sensitivity, and specificity for plaques are higher than those of blank nano-microbubbles. Similarly, the peak intensity and average transit time of VEGFR-2 targeting antibody nano-microbubbles were greater than those of blank nano-microbubbles. Therefore, we believe that the combination of VEGFR-2 antibody and nano-microbubbles can enhance the acquisition of ultrasound information on atherosclerotic plaque neovascularization, thereby improving the early diagnosis of unstable plaque.

Accelerated Two-Point Dixon MR Angiography Improves Diagnostic Performance for Cervical Artery Diseases.

Nonenhanced MR angiography (MRA) studies are often used to manage acute and chronic large cervical artery disease, but lengthy scan times limit their clinical usefulness. To develop an accelerated cervical MRA and test its diagnostic performance. Prospective. Patients with cervical artery disease (n= 32, 17 males). 3.0 T; accelerated two-point Dixon three-dimensional Cartesian spoiled gradient-echo (FLEXA) and conventional time-of-flight MRA (cMRA) sequences. All patients underwent FLEXA (1'28″) and cMRA (6'47″) acquisitions. Quantitative evaluation (artery-to-background signal ratio and a blur metric) and qualitative evaluation using diagnostic performance measured by the sensitivity, specificity, and positive/negative predictive values (PPV/NPV), and vessel and plaque visualization scores from three board-certified radiologists' (with 10, 11, and 12 years of experience) independent readings using maximum intensity projection (MIP) for luminal diseases and axial images for plaque. The reference standards were contrast-enhanced angiography and fat-saturated T1-weighted images, respectively. All measures were compared between FLEXA and cMRA using the paired t, Wilcoxon signed-rank, McNemar's, or chi-squared test, as appropriate. Interreader agreement was assessed using Cohen's κ. P< 0.05 was considered statistically significant. The artery-to-background signal ratio was significantly higher for FLEXA (FLEXA: 7.20 ± 1.63 [fat]; 4.26 ± 0.52 [muscle]; cMRA: 2.57 ± 0.49 [fat]), while image blurring was significantly less (FLEXA: 0.24 ± 0.016; cMRA: 0.30 ± 0.029). In luminal disease detection, sensitivity (FLEXA: 0.97/0.91/0.91; cMRA:0.71/0.69/0.63), specificity (FLEXA: 0.98/0.93/0.98; cMRA:0.93/0.85/0.92), PPV (FLEXA: 0.92/0.86/0.86; cMRA: 0.64/0.5/0.58), and NPV (FLEXA: 0.99/0.98/0.98; cMRA: 0.92/0.91/0.9) were significantly higher for FLEXA. interreader agreement was substantial to almost perfect for FLEXA (κ= 0.82/0.86/0.78) and moderate to substantial for cMRA (κ= 0.67/0.56/0.57). MIP visualization scores were significantly higher for FLEXA, with substantial to almost perfect interreader agreement (FLEXA: κ= 0.83/0.86/0.82; cMRA: κ= 0.89/0.79/0.79). In plaque detection, sensitivity (FLEXA: 0.9/0.9/0.7; cMRA: 0.3/0.6/0.2) and specificity (FLEXA: 1/0.87/1; cMRA: 0.93/0.63/0.97) were significantly higher for FLEXA in two of three readers. The interreader plaque detection agreement was fair to substantial (FLEXA: κ= 0.63/0.69/0.48; cMRA: κ= 0.21/0.45/0.20). Side-by-side plaque and vessel wall visualization was superior for FLEXA in all readers, with moderate to substantial interreader agreement (plaque: κ= 0.73/0.73/0.77; vessel wall: κ= 0.57/0.40/0.39). FLEXA enhanced visualization of the cervical arterial system and improved diagnostic performance for luminal abnormalities and plaques in patients with cervical artery diseases. 1 TECHNICAL EFFICACY STAGE: 2.

Ultrasonic Imaging of Carotid Inflammatory Plaque with Superparamagnetic Nanoparticles.

Chronic inflammation can stimulate the formation and progression of atherosclerotic plaques and increase the vulnerability of plaques. However, there are few studies on the changes of carotid inflammatory plaques during treatment. Our study attempted to investigate the use of superparamagnetic iron oxide nanoparticle (SPION) ultrasound imaging to detect the expression of vascular cell adhesion molecule-1 (VCAM-1) in patients with carotid plaques and analyze the effects of SPION ultrasound imaging in inflammatory plaque visualization effect. SPION microbubble contrast agents have good imaging effects both in vivo and in vitro. We conjugated the VCAM-1 protein to the microbubbles wrapped in SPIONs to form SPIONs carrying VCAM-1 antibodies. Observe the signal intensity of SPIONs carrying VCAM-1 antibody to arteritis plaque. The results showed that the SPION contrast agent carrying VCAM-1 antibody had higher peak gray-scale video intensity than the other two groups of contrast agents not carrying VCAM-1 antibody. It shows that SPIONs have excellent imaging effects in ultrasound imaging, can evaluate the inflammatory response of arterial plaque lesions, and are of great significance for the study of carotid inflammatory plaque changes.

Benefits of Using Fluorescence Induced Theragnosis in Fixed Orthodontic Therapy: Status, Technology and Future Trends

Dental biofilm is often found to be the source of bacteria that releases toxins, peptides, lipopolysaccharides as well as organic acids, which lead to gingival inflammation and tooth caries. Further, the persistent plaque may result in the continued destruction of the surrounding soft and hard tissues. During fixed orthodontic therapy, arch-wires, brackets, and elastic modules have been shown to be sites of significant plaque accumulation, making it difficult for a patient to maintain proper oral hygiene. The problem most dentists face is that they cannot visualize this biofilm completely to be able to carry out efficient plaque removal. Visual assessment is, to date, the most common method for plaque visualization, and various indexes have been demonstrated to be sufficient for quantification of the amount of plaque present. However, the problem is that visual assessments are inconsistent, operator dependent and often subjective, which can lead to inconsistency in results. Fluorescence is one such method that can be explored for its use in effective plaque identification and removal. Literature has it that dentists and patients find it particularly useful for monitoring oral hygiene status during treatment. Fluorescence has the capability of offering clinical orthodontists and researchers a new method of detection of demineralization during orthodontic treatment, furthermore, for efficient removal of orthodontic adhesive cements, fluorescent light may be used in conjunction with high-speed burs to deliver fast, less time consuming, and safer results. The benefit of direct visual treatment using fluorescence enhanced theragnosis is that the patient receives controlled and guided therapy. It has multiple benefits, such as early diagnosis of caries, biofilm identification, and even helps to achieve improved treatment outcomes by better resin selection for esthetic procedures.

Volumetric multispectral optoacoustic tomography of beta‐amyloid deposits in whole mouse brain

AbstractBackgroundThe abnormal deposition of fibrillar beta‐amyloid deposits in the brain is one of the major histopathological hallmarks of Alzheimer’s disease. Currently 3D imaging using positron emission tomography for plaque visualization is of a limited resolution (1 mm) in relation to the size of mouse brain in widely used AD models.MethodWe developed a novel high‐resolution non‐invasive volumetric multi‐spectral optoacoustic tomography (vMSOT) of 100 mm resolution using amyloid probe AOI987 to visualize amyloid‐beta distribution in arcAβ and APP/PS1 transgenic mouse models of cerebral amyloidosis. Immunohistochemical staining was performed with AOI987, anti‐Aβ antibody 6E10 and fibrillar amyloid conformation antibody OC on mouse brain sections.Result In vivo vMSOT detects higher Aβ load in the cortex, hippocampus and thalamus of arcAβ mice, and in the cortex of APP/PS1 mice compared to non‐transgenic littermates, corresponding with immunohistochemical staining results in mouse brain sections. Confocal microscopy showed co‐localization of AOI987, 6E10 and OC to parenchymal and cerebral amyloid angiopathy in brain tissue sections from arcAb and APP/PS1 mice, thus verifying the specificity of the vMSOT amyloid imaging approach.ConclusionWe demonstrate a new high‐resolution in vivo 3D amyloid imaging platform across the murine brain in animal models of AD pathology, which facilitates mechanistic studies and the monitoring of putative treatments targeting Aβ.

Transcranial detection of amyloid‐beta at single plaque resolution in vivo with large‐field multifocal illumination fluorescence microscopy

AbstractBackgroundThe abnormal deposition of beta‐amyloid proteins in the brain is one of the major histopathological hallmarks of Alzheimer’s disease. Currently available intravital microscopy techniques for high‐resolution plaque visualization commonly involve highly invasive procedures and are limited to small field‐of‐views within the rodent brain.MethodWe devised a large‐field multi‐focal illumination (LMI) fluorescence microscopy method that provides a 20 × 20 mm field‐of‐view and an axial resolution of ∼15 mm. In vivo and ex vivo transcranial LMI fluorescence microscopy and wide‐field fluorescence microscopy for amyloid deposits were performed in APP/PS1 and arcAb mouse models of Alzheimer’s disease amyloidosis using luminescent conjugated oligothiophene probe HS‐169. Immunohistochemical staining with HS‐169, anti‐Ab antibody 6E10, and conformation antibodies OC (fibrillar) of brain tissue sectionsResultLMI fluorescence microscopy detected amyloid‐beta deposits at a single plaque level in APP/PS1 and arcAb mice with high sensitivity and specificity. The contrast‐to‐noise ratio was approximately 24 times higher in LMI fluorescence microscopy of amyloid deposits compared to wide‐field fluorescence microscopy. Immunohistochemical staining showed HS‐169 co‐localized with 6E10 and OC stained compact parenchymal and vessel‐associated amyloid deposits.ConclusionThe novel LMI in vivo amyloid imaging platform offers new prospects for studies into Alzheimer’s disease mechanisms in animal models as well as longitudinal monitoring of therapeutic responses at a single plaque level.

Photon-counting CT with tungsten as contrast medium: Experimental evidence of vessel lumen and plaque visualization

Background and aimsWe aimed to investigate the potential of a preclinical photon-counting detector CT (PCT) scanner with an experimental tungsten-based contrast medium for carotid artery imaging. MethodsA carotid artery specimen was imaged on a PCT system using the multi-energy bin option (pixel size 0.5 × 0.5 mm2; tube voltage 140 kVp, contrast media-dependent energy thresholds: iodine 20, 75 keV; tungsten 20, 68 keV) at two radiation doses (CTDIvol of 100 mGy and 10 mGy) with iodine and tungsten as contrast media at equal mass-concentrations. Standard CT, virtual non-calcium (VNCa) and calcium-only images were reconstructed. Subjective image quality (4-point Likert scale) was rated using histology as reference. Noise and attenuation measurements were performed. Simulations were conducted to assess the material-decomposition efficiency for different object diameters. ResultsImage quality on VNCa images was significantly higher for tungsten at lower dose (reader 1/reader 2: 2, [2,2]/2, [2,2] vs 1.5, [2,1]/1, [1,1.75], p < 0.05). Noise was significantly lower at both dose levels for tungsten VNCa images as compared to iodine images (higher dose: tungsten 24 vs iodine 31; lower dose: tungsten 60 vs iodine 82; both p < 0.01). Simulations indicated improved material-decomposition efficiency for tungsten than for iodine pronounced at smaller object diameters. ConclusionsPCT employing the multi-energy bin option in combination with tungsten as contrast media enables improved carotid artery imaging with respect to lumen and plaque visualization and image noise.

Utility of Intravascular Ultrasound in Peripheral Vascular Interventions: Systematic Review and Meta-Analysis.

We sought to compare outcomes between intravascular ultrasound- (IVUS) versus angiography (AO)-guided peripheral vascular interventions (PVIs). Introduction: Intravascular ultrasound facilitates plaque visualization and angioplasty during PVIs for peripheral arterial disease. It is unclear whether IVUS may improve the durability of PVIs and lead to improved clinical outcomes. This is a study-level meta-analysis of observational studies. The primary end points of this study were rates of primary patency and reintervention. Secondary end points included rates of vascular complications, periprocedural adverse events, amputations, technical success, all-cause mortality, and myocardial infarction. Eight observational studies were included in this analysis with 93 551 patients. Mean follow-up was 24.2 ± 15 months. Intravascular ultrasound-guided PVIs had similar patency rates when compared with AO-guided PVIs (relative risk [RR]: 1.30, 95% confidence interval [CI]: 0.99-1.71, P = .062). There was no difference in rates of reintervention in IVUS-guided PVIs when compared to non-IVUS-guided PVIs (RR: 0.41, 95% CI: 0.15-1.13, P = .085). There is a lower risk of periprocedural adverse events (RR: 0.81, 95% CI: 0.70-0.94, P = .006) and vascular complications (RR: 0.81, 95% CI: 0.68-0.96, P = .013) in the IVUS group. All-cause mortality (RR: 0.76, 95% CI: 0.56-1.04, P = .084), amputation rates (RR 0.83, 95% CI: 0.32-2.15, P = .705), myocardial infarctions (RR: 1.19, 95% CI: 0.58-2.41, P = .637), and technical success (RR: 1.01, 95% CI: 0.86-1.19, P = .886) were similar between the groups. Conclusions: Intravascular ultrasound-guided PVIs had similar primary patency and reintervention when compared with AO-guided PVIs with significantly lower rates of periprocedural adverse events and vascular complications in the IVUS-guided group.

Comparison of dental plaque reduction after use of electric toothbrushes with and without QLF-D-applied plaque visualization: a 1-week randomized controlled trial

BackgroundTo evaluate the efficacy of a newly developed electric toothbrush in reducing dental plaque via a quantitative light-induced fluorescence-digital (QLF-D)-applied visualisation system in the brush head.MethodsParticipants included 20 adults aged 19 to 28 years. Participants were randomly assigned either (i) an electric toothbrush with a monitor to visualise red-fluorescent dental plaque via a camera built into the brush head (monitor usage group, n = 10) or (ii) an electric toothbrush without a monitor (monitor-non-use group, n = 10). The amount of dental plaque was assessed by personal hygiene performance (PHP) at baseline and 1 week later.ResultsIn the monitor-usage group, PHP score was significantly lower at the 1-week follow-up than at baseline (6 vs 16; range, 0–12 vs 13–21; P = 0.029). This change was not observed in the monitor-non-use group (14 vs 13; range, 6–21 vs 2–26; P = 0.778). After 1 week, the change in PHP scores in the monitor usage group was significantly greater than that in the monitor non-use group (− 10 vs 0; range, − 21 to 9 vs − 8 to 16; P = 0.021).ConclusionsOur results clearly demonstrate that brushing teeth while looking at a monitor that depicts red-autofluorescent dental plaque via application of QLF-D improved the efficacy of dental-plaque removal relative to brushing teeth without a monitor.Trial registrationTrial registration number: UMIN000033699.Name of registry: Study on effect of new devise for oral care on dental plaque clearance.Date of registration: 8th September 2018.Status of registration: Completed.

Mechanical Characterization of the Vessel Wall by Data Assimilation of Intravascular Ultrasound Studies

Atherosclerotic plaque rupture and erosion are the most important mechanisms underlying the sudden plaque growth, responsible for acute coronary syndromes and even fatal cardiac events. Advances in the understanding of the culprit plaque structure and composition are already reported in the literature, however, there is still much work to be done toward in-vivo plaque visualization and mechanical characterization to assess plaque stability, patient risk, diagnosis and treatment prognosis. In this work, a methodology for the mechanical characterization of the vessel wall plaque and tissues is proposed based on the combination of intravascular ultrasound (IVUS) imaging processing, data assimilation and continuum mechanics models within a high performance computing (HPC) environment. Initially, the IVUS study is gated to obtain volumes of image sequences corresponding to the vessel of interest at different cardiac phases. These sequences are registered against the sequence of the end-diastolic phase to remove transversal and longitudinal rigid motions prescribed by the moving environment due to the heartbeat. Then, optical flow between the image sequences is computed to obtain the displacement fields of the vessel (each associated to a certain pressure level). The obtained displacement fields are regarded as observations within a data assimilation paradigm, which aims to estimate the material parameters of the tissues within the vessel wall. Specifically, a reduced order unscented Kalman filter is employed, endowed with a forward operator which amounts to address the solution of a hyperelastic solid mechanics model in the finite strain regime taking into account the axially stretched state of the vessel, as well as the effect of internal and external forces acting on the arterial wall. Due to the computational burden, a HPC approach is mandatory. Hence, the data assimilation and computational solid mechanics computations are parallelized at three levels: (i) a Kalman filter level; (ii) a cardiac phase level; and (iii) a mesh partitioning level. To illustrate the capabilities of this novel methodology toward the in-vivo analysis of patient-specific vessel constituents, mechanical material parameters are estimated using in-silico and in-vivo data retrieved from IVUS studies. Limitations and potentials of this approach are exposed and discussed.

Abstract WP112: Association and Discordance Between Magnetic Resonance Angiography and Three-Dimensional Vessel Wall Imaging in Detecting Intracranial Atherosclerosis

Background: Evaluation of intracranial atherosclerosis currently relies on angiography techniques to detect luminal stenosis, among which 3D time-of-flight (TOF) MRA is most widely used. Recently, 3D vessel wall (VW) MRI has allowed direct plaque visualization in major intracranial arteries. Purpose: We sought to study the association between luminal stenosis on TOF-MRA and plaque on VW-MRI in major intracranial arteries. Methods: Patients with recent cerebral ischemic events and without cardioembolic or rare etiologies were scanned with intracranial TOF-MRA (resolution: 0.53x0.83x1.4 mm 3 ) and VW-MRI (0.8x0.8x0.8 mm 3 ). Eleven segments were evaluated, including cavernous and supraclinoid internal carotid artery (ICA), anterior cerebral artery (A1), middle cerebral artery (M1), basilar artery, and posterior cerebral artery (P1). TOF-MRA and VW-MRI were analyzed blinded to each other and clinical data. Luminal stenosis on TOF-MRA was categorized as mild (1-49%), moderate (50-69%), severe (70-99% or flow void), and occlusion (100%). Plaque on VW-MRI was defined as focal wall thickening that exceeded twice reference wall thickness, with plaque burden measured as 1 - lumen diameter / outer wall diameter at the level of maximum wall thickness. Results: Nineteen patients were recruited (59.4±14.3 years; 68.4% male). TOF-MRA detected stenosis in 28 segments while VW-MRI detected plaque in 88 segments. Sixty-three (71.6%) plaques on VW-MRI did not show luminal stenosis on TOF-MRA, which, compared to those showing luminal stenosis on TOF-MRA, had smaller plaque burden (0.48±0.09 vs. 0.58±0.11; p&lt;0.001) and were more commonly localized in the supraclinoid ICA (p=0.029) and less likely in the A1 segment (p=0.043). Three (2 mild; 1 moderate) stenoses on TOF-MRA did not show plaque on VW-MRI. TOF-MRI and VW-MRI had a weak correlation both in detecting segmental atherosclerosis (Cohen’s kappa: 0.30 [0.20, 0.41]) and in evaluating lesion severity (stenosis vs. plaque burden; Spearman’s rho: 0.44 [0.25, 0.60]). Conclusions: In symptomatic patients, segmental atherosclerosis was three times more prevalent on VW-MRI than TOF-MRA. Further studies are warranted to understand the clinical implications of VW-MRI plaques that are undetected on TOF-MRA.

High resolution simultaneous imaging of intracranial and extracranial arterial wall with improved cerebrospinal fluid suppression

PurposeTo develop a technique for three dimensional (3D) high resolution joint imaging of intracranial and extracranial arterial walls with improved cerebrospinal fluid (CSF) suppression and good blood suppression based on T1 weighted sampling perfection with application optimized contrast using different angle evolutions (T1w-SPACE) and to compare this technique (hereafter, iSPACE) with alternating with nutation for tailored excitation (DANTE) prepared SPACE sequence (DANTE-SPACE) for their CSF suppression performance around the mid cerebral arteries (MCA) and blood suppression at carotid arteries. Materials and methodsEight volunteers and twelve patients were prospectively recruited in this institutional review board approved study. A custom designed 32-channel coil set covering the intracranial and extracranial arteries was used for signal reception. Imaging was performed in each subject using DANTE-SPACE and iSPACE. Signal-to-noise ratios (SNR) of the vessel walls at the MCA and carotid arteries, and contrast-to-noise ratios (CNR) between vessel wall and CSF at the MCA and between vessel wall and lumen at carotid arteries from the two sequences were compared. ResultsIn volunteers, contrast between CSF and white matter (surrogate for vessel wall signal) at the M2 segments in iSPACE was 67.9% higher than in DANTE-SPACE. At the carotid region, the SNR of vessel wall in iSPACE was 11.6% higher than DANTE-SPACE while the CNR in iSPACE was 13% higher than DANTE-SPACE. In patients, images with 0.6mm isotropic resolution were obtained in 7.5min. iSPACE showed 70.9% improvement in CNR between plaque and CSF at the M2 segments compared to DANTE-SPACE. ConclusionSimultaneous extracranial and intracranial arterial wall imaging using iSPACE improved CSF suppression significantly at the M2 segment of MCA while blood suppression was comparable to DANTE-SPACE. The technique achieved 3D images with 0.6mm isotropic spatial resolution and took 7.5min using a custom made coil set. Using this technique, intracranial plaque visualization was improved with no observable image SNR degradation.