Assessment Of Atherosclerotic Plaques Research Articles

The significance of ultrasonographic characteristics in the comprehensive radiological assessment of «high risk» carotid stenoses

Background. The prevalence of asymptomatic carotid stenosis (ACS) requires the existence of an algorythm to identify patients at risk of ischemic stroke. Assessment of carotid atherosclerotic plaque (AP) based on its morphology and composition in addition to the quantitative parameter «stenosis» is possible using a complex of radiological studies including ultrasonographic ones, that can be deepened by new ultrasound techniques. Purpose – define ultrasonographic criteria for vulnerable carotid plaque based on evaluation of plaque characteristics using current ultrasonic techniques. Materials and methods. The study is based on the analysis of data obtained from 105 patients aged 41 to 84, diagnosed with stenosis of the internal carotid artery (ICA) according to ultrasonography (US). Examination methods – clinical, duplex US with the inclusion of shear wave elastography (SWE) and superb microvascular imaging (SMI) techniques to assess plaque stiffness and plaque microvascularisation; brain MRI, MSСT angiography (MSCTA), statistical. Two age-matched group were formed: a group with symptomatic carotid stenosis (SCS), 55 patients, and a group with asymptomatic carotid stenosis (ACS), 50 patients. Results. Statistically significant differences in the groups of patients with and without stroke were determined according to the following parameters of carotid plaques: quantitative criteria – maximum thickness (p = 0,02), with an AP thickness of more than 3.5 mm, the risk of stroke increases 2.2 times (p = 0,03), stenosis degree according to the NASCET protocol (p = 0,01 in the right ICA), plaque stiffness indicator according to SWE data (p = 0,001); qualitative criteria – type of plaque echogenicity according to the Gray-Weale classification (p = 0,001), presence of microvascularization according to SMI data (p = 0,04). Correlation of AP stiffness indicators according to SWE and MSCTA data (ρ = 0,60; р = 0,004) was established, as well as between AP stiffness according to SWE data and echo- type of AP (τ = 0,56; р = 0,006). Conclusions. Determination of plaque thickness greater than 3.5 mm, low plaque stiffness according to SWE data, the presence of microvascularization according to SMI data it is advisable to add to the complex of radiological assessment of carotid stenosis with a high risk of ischemic events, in addition to the standard US criteria of stenosis degree and AP echo-type.

ESR Essentials: imaging in stable chest pain - practice recommendations by ESCR.

Stable chest pain is a common symptom with multiple potential causes. Non-invasive imaging has an important role in diagnosis and guiding management through the assessment of coronary stenoses, atherosclerotic plaque, myocardial ischaemia or infarction, and cardiac function. Computed tomography (CT) provides the anatomical evaluation of coronary artery disease (CAD) with the assessment of stenosis, plaque type and plaque burden, with additional functional information available from CT fractional flow reserve (FFR) or CT myocardial perfusion imaging. Stress magnetic resonance imaging, nuclear stress myocardial perfusion imaging, and stress echocardiography can assess myocardial ischaemia and other cardiac functional parameters. Coronary CT angiography can be used as a first-line test for many patients with stable chest pain, particularly those with low to intermediate pre-test probability. Functional testing may be considered for patients with known CAD, where the clinical significance is uncertain based on anatomical testing, or in patients with high pre-test probability. This practice recommendations document can be used to guide the selection of non-invasive imaging for patients with stable chest pain and provides brief recommendations on how to perform and report these diagnostic tests.

Role of Imaging Modalities in the Quantitative Assessment of Atherosclerotic Plaques in the Thoracic Aorta.

Comparative analysis of the height of atherosclerotic plaques (AP) in the descending thoracic aorta (TA) according to two-dimensional (2D) and three-dimensional (3D) transesophageal echocardiography (TEE), and contrast-enhanced multislice computed tomography (MSCT). The TA was examined using 2D, 3D TEE and contrast-enhanced MSCT in 34 patients (20 men and 14 women aged 68 [62; 71] years). AP heights were compared using the Bland-Altman method and the Spearman correlation analysis. This was a blinded comparative study which assessed the AP morphometry using each of the radiation modalities without knowing the results of the method being compared. 100 APs were examined in the descending TA. The mean height of all analyzed APs in the descending TA was 2.2 mm [2; 2.7] for 2D TEE, 3.1 mm [2.7; 3.55] for 3D TEE, and 3.05 mm [2.55; 3.55] for MSCT. The AP heights measured with 2D TEE was statistically significantly smaller than the heights of similar APs measured either with 3D TEE or MSCT. The mean difference (bias) was 0.88±0.34 mm between 2D and 3D TEE, and 0.83±0.41 mm between 2D TEE and MSCT. The correlation coefficients for the AP heights were r=0.87 (p<0.001) between 2D and 3D TEE and r=0.86 (p<0.001) between 2D TEE and MSCT. There were no differences in the height of similar APs between 3D TEE and MSCT. The three-dimensional reconstruction of AP in the TA by TEE is more accurate for quantitative assessment of AP than a two-dimensional study.

Comparison of Two Contemporary Quantitative Atherosclerotic Plaque Assessment Tools for Coronary Computed Tomography Angiography: Single-Center Analysis and Multi-Center Patient Cohort Validation.

Coronary computed tomography angiography (CCTA) provides non-invasive quantitative assessments of plaque burden and composition. The quantitative assessment of plaque components requires the use of analysis software that provides reproducible semi-automated plaque detection and analysis. However, commercially available plaque analysis software can vary widely in the degree of automation, resulting in differences in terms of reproducibility and time spent. To compare the reproducibility and time spent of two CCTA analysis software tools using different algorithms for the quantitative assessment of coronary plaque volumes and composition in two independent patient cohorts. The study population included 100 patients from two different cohorts: 50 patients from a single-center (Siemens Healthineers, SOMATOM Force (DSCT)) and another 50 patients from a multi-center study (5 different > 64 slice CT scanner types). Quantitative measurements of total calcified and non-calcified plaque volume of the right coronary artery (RCA), left anterior descending (LAD), and left circumflex coronary artery (LCX) were performed on a total of 300 coronaries by two independent readers, using two different CCTA analysis software tools (Tool #1: Siemens Healthineers, syngo.via Frontier CT Coronary Plaque Analysis and Tool #2: Siemens Healthineers, successor CT Coronary Plaque Analysis prototype). In addition, the total time spent for the analysis was recorded with both programs. The patients in cohorts 1 and 2 were 62.8 ± 10.2 and 70.9 ± 11.7 years old, respectively, 10 (20.0%) and 35 (70.0%) were female and 34 (68.0%) and 20 (40.0%), respectively, had hyperlipidemia. In Cohort #1, the inter- and intra-observer variabilities for the assessment of plaque volumes per patient for Tool #1 versus Tool #2 were 22.8%, 22.0%, and 26.0% versus 2.3%, 3.9%, and 2.5% and 19.7%, 21.4%, and 22.1% versus 0.2%, 0.1%, and 0.3%, respectively, for total, noncalcified, and calcified lesions (p < 0.001 for all between Tools #1 and 2 both for inter- and intra-observer). The inter- and intra-observer variabilities using Tool #2 remained low at 2.9%, 2.7%, and 3.0% and 3.8%, 3.7%, and 4.0%, respectively, for total, non-calcified, and calcified lesions in Cohort #2. For each dataset, the median processing time was higher for Tool #1 versus Tool #2 (459.5 s IQR = 348.0-627.0 versus 208.5 s; IQR = 198.0-216.0) (p < 0.001). The plaque analysis Tool #2 (CT-guided PCI) encompassing a higher degree of automated support required less manual editing, was more time-efficient, and showed a higher intra- and inter-observer reproducibility for the quantitative assessment of plaque volumes both in a representative single-center and in a multi-center validation cohort.

Association of oxidized ApoB and oxidized ApoA-I with high-risk coronary plaque features in cardiovascular disease.

Oxidized apolipoprotein B (oxLDL) and oxidized ApoA-I (oxHDL) are proatherogenic. Their prognostic value for assessing high-risk plaques by coronary computed tomography angiography (CCTA) is missing. In a prospective, observational study, 306 participants with cardiovascular disease (CVD) had extensive lipoprotein profiling. Proteomics analysis was performed on isolated oxHDL, and atherosclerotic plaque assessment was accomplished by quantitative CCTA. Patients were predominantly White, overweight men (58.5%) on statin therapy (43.5%). Increase in LDL-C, ApoB, small dense LDL-C (P < 0.001 for all), triglycerides (P = 0.03), and lower HDL function were observed in the high oxLDL group. High oxLDL associated with necrotic burden (NB; β = 0.20; P < 0.0001) and fibrofatty burden (FFB; β = 0.15; P = 0.001) after multivariate adjustment. Low oxHDL had a significant reverse association with these plaque characteristics. Plasma oxHDL levels better predicted NB and FFB after adjustment (OR, 2.22; 95% CI, 1.27-3.88, and OR, 2.80; 95% CI, 1.71-4.58) compared with oxLDL and HDL-C. Interestingly, oxHDL associated with fibrous burden (FB) change over 3.3 years (β = 0.535; P = 0.033) when compared with oxLDL. Combined Met136 mono-oxidation and Trp132 dioxidation of HDL showed evident association with coronary artery calcium score (r = 0.786; P < 0.001) and FB (r = 0.539; P = 0.012) in high oxHDL, whereas Met136 mono-oxidation significantly associated with vulnerable plaque in low oxHDL. Our findings suggest that the investigated oxidized lipids are associated with high-risk coronary plaque features and progression over time in patients with CVD. gov NCT01621594. National Heart, Lung, and Blood Institute at the NIH Intramural Research Program.

Echogenicity of carotid atherosclerotic plaques as a predictor of adverse cardiovascular events in patients aged 40–64: prospective study

INTRODUCTION: Noninvasive assessment of carotid atherosclerotic plaque (CAP) morphology represents a promising direction, allowing to optimize not only cardiovascular event risk assessment, but also the selection of patients for carotid revascularization. Determination of CAP echogenicity by means of GSM-analysis can be used as part of multiparametric assessment of CAP instability and prediction of adverse cardiovascular events.OBJECTIVE: To assess the predictive value of echogenicity of carotid atherosclerotic plaques in relation to the development of adverse cardiovascular events in patients 40–64 years old.MATERIALS AND METHODS: The study included 191 patients with carotid atherosclerosis aged 40–64 years. All patients underwent duplex scanning of the arteries of the carotid basin with determination of the echogenicity of carotid ASBs. The combined end point (CEP) consisted of the following possible events: nonfatal myocardial infarction or unstable angina, nonfatal stroke, coronary revascularization or peripheral artery revascularization, and death from cardiovascular causes. Data on the onset of CVD were collected during follow-up visits and using medical information systems. Statistics: Data were analyzed using MedCalc software (version 20.216). Frequencies and percentages were used to describe nominal data, and medians and quartiles were used for quantitative data. The Kaplan-Meier survival analysis method was used to estimate the probability of events constituting the combined endpoint. Cox regression analysis was used to estimate the risk of the event and the influence of independent variables on the risk.RESULTS: By correlation analysis, carotid AP echogenicity (GSM) was inversely correlated with BMI (r=-0,355; p&lt;0,0001), waist circumference (r=-0.37; p&lt;0.0001), triglyceride levels (r=-0.163; p=0.027), uric acid (r=-0.188; p=0.028). The duration of the follow-up period was 15.1 (12.2; 22.9) months. Events constituting CEP occurred in 15 (7.85%) patients: nonfatal myocardial infarction in 2 (1.05%) patients, nonfatal stroke in 2 (1.05%) patients, myocardial revascularization in 6 (3.14%) patients, unstable angina in 5 (2.61%) patients. The presence of carotid AP with echogenicity ≤39 conventional units allowed predicting the development of events constituting CEP with sensitivity of 53.3% and specificity of 80.7%. Kaplan-Meier survivalanalysis revealed that cumulative survival of patients with carotid AP with echogenicity ≤39 conventional units was statistically significantly lower compared to patients with carotid ASB with echogenicity &gt;39 conventional units.DISCUSSION: It should be noted that in the presented study, decreased echogenicity of carotid AP was associated with the risk of adverse cardiovascular events only in the simple and sex- and age-adjusted models, but not in the full-adjusted model. It is likely that this may be due to the fact that the echogenicity of CAP is closely related to the cumulative burden of cardiovascular risk factors, which has been shown in earlier studies including. Probably, combined assessment of carotid atherosclerosis burden and morphological features of CAP may be the most promising approach to obtain additional prognostic information in patients with carotid atherosclerosis.CONCLUSION: Among patients with carotid atherosclerosis 40–64 years old, the presence of ACS with echogenicity ≤39 conventional units was associated with a 3.44 (95% CI 1.19–9.91) fold increase in the relative risk of events constituting the combined endpoint after adjusting for sex and age.

Exploring atherosclerosis imaging with contrast-enhanced MRI using PEGylated ultrasmall iron oxide nanoparticles.

Plaque rupture is a critical concern due to its potential for severe outcomes such as cerebral infarction and myocardial infarction, underscoring the urgency of noninvasive early diagnosis. Magnetic resonance imaging (MRI) has gained prominence in plaque imaging, leveraging its noninvasiveness, high spatial resolution, and lack of ionizing radiation. Ultrasmall iron oxides, when modified with polyethylene glycol, exhibit prolonged blood circulation and passive targeting toward plaque sites, rendering them conducive for MRI. In this study, we synthesized ultrasmall iron oxide nanoparticles of approximately 3nm via high-temperature thermal decomposition. Subsequent surface modification facilitated the creation of a dual-modality magnetic resonance/fluorescence probe. Upon intravenous administration of the probes, MRI assessment of atherosclerotic plaques and diagnostic evaluation were conducted. The application of Flash-3D sequence imaging revealed vascular constriction at lesion sites, accompanied by a gradual signal amplification postprobe injection. T1-weighted imaging of the carotid artery unveiled a progressive signal ratio increase between plaques and controls within 72h post-administration. Fluorescence imaging of isolated carotid arteries exhibited incremental lesion-to-control signal ratios. Additionally, T1 imaging of the aorta demonstrated an evolving signal enhancement over 48h. Therefore, the ultrasmall iron oxide nanoparticles hold immense promise for early and noninvasive diagnosis of plaques, providing an avenue for dynamic evaluation over an extended time frame.

Age- and Sex-Specific Nomographic CT Quantitative Plaque Data From a Large International Cohort

BackgroundWith growing adoption of coronary computed tomographic angiography (CTA), there is increasing evidence for and interest in the prognostic importance of atherosclerotic plaque volume. Manual tools for plaque segmentation are cumbersome, and their routine implementation in clinical practice is limited. ObjectivesThe aim of this study was to develop nomographic quantitative plaque values from a large consecutive multicenter cohort using coronary CTA. MethodsQuantitative assessment of total atherosclerotic plaque and plaque subtype volumes was performed in patients undergoing clinically indicated coronary CTA, using an Artificial Intelligence–Enabled Quantitative Coronary Plaque Analysis tool. ResultsA total of 11,808 patients were included in the analysis; their mean age was 62.7 ± 12.2 years, and 5,423 (45.9%) were women. The median total plaque volume was 223 mm3 (IQR: 29-614 mm3) and was significantly higher in male participants (360 mm3; IQR: 78-805 mm3) compared with female participants (108 mm3; IQR: 10-388 mm3) (P < 0.0001). Total plaque increased with age in both male and female patients. Younger patients exhibited a higher prevalence of noncalcified plaque. The distribution of total plaque volume and its components was reported in every decile by age group and sex. ConclusionsThe authors developed pragmatic age- and sex-stratified percentile nomograms for atherosclerotic plaque measures using findings from coronary CTA. The impact of age and sex on total plaque and its components should be considered in the risk-benefit analysis when treating patients. Artificial Intelligence–Enabled Quantitative Coronary Plaque Analysis work flows could provide context to better interpret coronary computed tomographic angiographic measures and could be integrated into clinical decision making.

Current Applications and New Perspectives in Optical Coherence Tomography (OCT) Coronary Atherosclerotic Plaque Assessment: From PCI Optimization to Pharmacological Treatment Guidance

Since its ability to precisely characterized atherosclerotic plaque phenotypes, to tailor stent implantation, as well as to guide both complex percutaneous coronary interventions (PCI) and invasive diagnostic work-ups (e.g., spontaneous coronary dissections or myocardial infarction with non-obstructive arteries), the adoption of optical coherence tomography (OCT) was raised in the past decades in order to provide complementary information to the traditional angiography and to overcome its limitations. However, the impact of OCT on daily clinical practice is currently modest, firstly because of the lack of both standardized algorithms of PCI guidance and data from prospective clinical trials. Therefore, the aim of our narrative review is to provide a comprehensive overview of the basic OCT interpretation, to summarize the evidence supporting the OCT guidance procedures and applications, to discuss its current limitations, and to highlight the knowledge gaps that need to be filled with more robust evidence.

Recent progress of coronary computed tomography angiography for atherosclerotic plaque assessment and cardiac risk prediction

Recent progress of coronary computed tomography angiography for atherosclerotic plaque assessment and cardiac risk prediction

The Assessment of Carotid Atherosclerotic Plaque among Young Patients with Familial Hypercholesterolemia.

Objective Few data exist regarding when atherosclerotic changes occur among patients with familial hypercholesterolemia (FH). Carotid ultrasonography is a non-invasive method of evaluating this issue. The present study (1) compared the clinical utilities of carotid intima-media thickness (cIMT) and carotid plaque score (cPS) and (2) estimated the onset and progression of carotid atherosclerosis among patients with heterozygous FH (HeFH). Methods We retrospectively analyzed 511 patients under 30 years old who underwent carotid ultrasonography at our hospital from 2006 to 2019. We classified them into the HeFH group (n=78, 21.4±5.9 years old) and non-FH group (n=433, 23.4±6.0 years old) based on the clinical diagnosis and compared their cIMT and cPS values. In addition, we estimated the onset and progression of carotid atherosclerosis among young HeFH patients. Results There was no significant difference in the cIMT between the HeFH and non-FH groups (0.44 mm vs. 0.42 mm, p=0.25). In contrast, the cPS was significantly higher in the HeFH group than in the non-FH group (1.11 vs. 0.26, p=0.002). The regression equation for cPS of HeFH group was Y=-2.05+0.15X (r=0.37, p<0.001). Conclusion An assessment based on the cPS rather than the cIMT appears to be better to capture the progress of carotid atherosclerosis among young HeFH patients. Carotid atherosclerosis may start to develop at 14 years old in patients with HeFH.

Rapid lipid-laden plaque identification in intravascular optical coherence tomography imaging based on time-series deep learning.

Coronary heart disease has the highest rate of death and morbidity in the Western world. Atherosclerosis is an asymptomatic condition that is considered the primary cause of cardiovascular diseases. The accumulation of low-density lipoprotein triggers an inflammatory process in focal areas of arteries, which leads to the formation of plaques. Lipid-laden plaques containing a necrotic core may eventually rupture, causing heart attack and stroke. Lately, intravascular optical coherence tomography (IV-OCT) imaging has been used for plaque assessment. The interpretation of the IV-OCT images is performed visually, which is burdensome and requires highly trained physicians for accurate plaque identification. Our study aims to provide high throughput lipid-laden plaque identification that can assist in vivo imaging by offering faster screening and guided decision making during percutaneous coronary interventions. An A-line-wise classification methodology based on time-series deep learning is presented to fulfill this aim. The classifier was trained and validated with a database consisting of IV-OCT images of 98 artery sections. A trained physician with expertise in the analysis of IV-OCT imaging provided the visual evaluation of the database that was used as ground truth for training and validation. This method showed an accuracy, sensitivity, and specificity of 89.6%, 83.6%, and 91.1%, respectively. This deep learning methodology has the potential to increase the speed of lipid-laden plaques identification to provide a high throughput of more than 100B-scans/s. These encouraging results suggest that this method will allow for high throughput video-rate atherosclerotic plaque assessment through automated tissue characterization for in vivo imaging by providing faster screening to assist in guided decision making during percutaneous coronary interventions.

Advances in Noninvasive Carotid Wall Imaging with Ultrasound: A Narrative Review.

Carotid atherosclerosis is a major cause for stroke, with significant associated disease burden morbidity and mortality in Western societies. Diagnosis, grading and follow-up of carotid atherosclerotic disease relies on imaging, specifically ultrasound (US) as the initial modality of choice. Traditionally, the degree of carotid lumen stenosis was considered the sole risk factor to predict brain ischemia. However, modern research has shown that a variety of other imaging biomarkers, such as plaque echogenicity, surface morphology, intraplaque neovascularization and vasa vasorum contribute to the risk for rupture of carotid atheromas with subsequent cerebrovascular events. Furthermore, the majority of embolic strokes of undetermined origin are probably arteriogenic and are associated with nonstenosing atheromas. Therefore, a state-of-the-art US scan of the carotid arteries should take advantage of recent technical developments and should provide detailed information about potential thrombogenic (/) and emboligenic arterial wall features. This manuscript reviews recent advances in ultrasonographic assessment of vulnerable carotid atherosclerotic plaques and highlights the fields of future development in multiparametric arterial wall imaging, in an attempt to convey the most important take-home messages for clinicians performing carotid ultrasound.

Non-Invasive Modalities in the Assessment of Vulnerable Coronary Atherosclerotic Plaques.

Coronary atherosclerosis is a complex, multistep process that may lead to critical complications upon progression, revolving around plaque disruption through either rupture or erosion. Several high-risk features are associated with plaque vulnerability and may add incremental prognostic information. Although invasive imaging modalities such as optical coherence tomography or intravascular ultrasound are considered to be the gold standard in the assessment of vulnerable coronary atherosclerotic plaques (VCAPs), contemporary evidence suggests a potential role for non-invasive methods in this context. Biomarkers associated with deleterious pathophysiologic pathways, including inflammation and extracellular matrix degradation, have been correlated with VCAP characteristics and adverse prognosis. However, coronary computed tomography (CT) angiography has been the most extensively investigated technique, significantly correlating with invasive method-derived VCAP features. The estimation of perivascular fat attenuation as well as radiomic-based approaches represent additional concepts that may add incremental information. Cardiac magnetic resonance imaging (MRI) has also been evaluated in clinical studies, with promising results through the various image sequences that have been tested. As far as nuclear cardiology is concerned, the implementation of positron emission tomography in the VCAP assessment currently faces several limitations with the myocardial uptake of the radiotracer in cases of fluorodeoxyglucose use, as well as with motion correction. Moreover, the search for the ideal radiotracer and the most adequate combination (CT or MRI) is still ongoing. With a look to the future, the possible combination of imaging and circulating inflammatory and extracellular matrix degradation biomarkers in diagnostic and prognostic algorithms may represent the essential next step for the assessment of high-risk individuals.

Follow-up assessment of atherosclerotic plaques in acute ischemic stroke patients using high-resolution vessel wall MR imaging.

Data on evolution of intracranial plaques in acute ischemic stroke patients after receiving medical therapy is still limited. We aimed to investigate the plaque features associated with culprit lesions and to explore the plaque longitudinal changes during treatment using high-resolution vessel wall MR imaging (VW-MRI). Twenty-three patients (16 men; mean age, 51.4years ± 11.1) with acute ischemic stroke underwent 3-T VW-MRI for intracranial atherosclerosis and were taken follow-up assessments. Each identified plaque was retrospectively classified as culprit, probably culprit, or nonculprit. Plaque features were analyzed at both baseline and follow-up and were compared using paired t-test, paired Wilcoxon test, or McNemar's test. A total of 87 intracranial plaques were identified (23 [26.4%] culprit, 10 [11.5%] probably culprit, and 54 [62.1%] nonculprit plaques). The median time interval between initial and follow-up MRI scans was 8.0months. In the multiple ordinal logistic regression analysis, plaque contrast ratio (CR) (OR, 1.037; 95% CI, 1.013-1.062; P = 0.002) and surface irregularity (OR, 4.768; 95% CI, 1.064-21.349; P = 0.041) were independently associated with culprit plaques. During follow-up, plaque length, maximum thickness, normalized wall index (NWI), stenosis degree, and CR significantly decreased (all P-values < 0.05) in the culprit plaque group. The plaque NWI and CR dropped in the probably culprit plaques (P = 0.041, 0.026, respectively). In the nonculprit plaque group, only plaque NWI and stenosis degree showed significant decrement (P = 0.017, 0.037, respectively). Follow-up VW-MRI may contribute to plaque risk stratification and may provide valuable insights into the evolution of different plaques in vivo.

Assessment of Aortoiliac Atherosclerotic Plaque on CT in Prostate Cancer Patients Undergoing Treatment.

Traditionally, atherosclerotic risk factors for cardiovascular disease and cancer are assessed using coronary artery calcium scoring. However, this neglects the impact of atherosclerotic disease more proximal to the cancer site. This study assesses whether aortoiliac atherosclerotic plaque is associated with prostate cancer. The dataset consisted of abdominopelvic CT of 93 patients with prostate cancer and 186 asymptomatic patients who underwent CT colonography as an age- and gender-matched control group. Agatston scores were measured in the abdominal aorta, common iliac, and internal iliac arteries. The scores were evaluated for associations with age, Framingham risk score, and prostate cancer-related biomarkers, including prostate-specific antigen, Gleason score, tumor location, prostatectomy, androgen deprivation therapy, mortality, and bone metastasis. The atherosclerotic plaque of prostate cancer patients did not differ from the control group (p = 0.22) and was not correlated with any of the prostate cancer-related biomarkers (p > 0.05). However, Agatston scores of abdominal plaques correlated well with age (p < 0.001) and Framingham risk scores (p = 0.002).

Potential and Most Relevant Applications of Total Body PET/CT Imaging.

The introduction of total body (TB) PET/CT instruments over the past 2 years has initiated a new and exciting era in medical imaging. These instruments have substantially higher sensitivity (up to 68 times) than conventional modalities and therefore allow imaging the entire body over a short period. However, we need to further refine the imaging protocols of this instrument for different indications. Total body PET will allow accurate assessment of the extent of disease, particularly, including the entire axial and appendicular skeleton. Furthermore, delayed imaging with this instrument may enhance the sensitivity of PET for some types of cancer. Also, this modality may improve the detection of venous thrombosis, a common complication of cancer and chemotherapy, in the extremities and help prevent pulmonary embolism. Total body PET allows assessment of atherosclerotic plaques throughout the body as a systematic disease. Similarly, patients with widespread musculoskeletal disorders including both oncologic and nononcologic entities, such as degenerative joint disease, rheumatoid arthritis, and osteoporosis, may benefit from the use of TB-PET. Finally, quantitative global disease assessment provided by this approach will be superior to conventional measurements, which do not reflect overall disease activity. In conclusion, TB-PET imaging may have a revolutionary impact on day-to-day practice of medicine and may become the leading imaging modality in the future.

Improved Centerline Extraction in Fully Automated Coronary Ostium Localization and Centerline Extraction Framework using Deep Learning.

Coronary artery extraction in cardiac CT angiography (CCTA) image volume is a necessary step for any quantitative assessment of stenoses and atherosclerotic plaque. In this work, we propose a fully automated workflow that depends on convolutional networks to extract the centerlines of the coronary arteries from CCTA image volumes, starting from identifying the ostium points and then tracking the vessel till its end based on its radius and direction. First, a regression U-Net is employed to identify the ostium points in the image volume, then these points are fed to an orientation and radius predictor CNN model to track and extract each artery till its end point. Our results show that an average of 96% of the ostium points were identified and located within less than 5mm from their true location. The coronary arteries centerlines extraction was performed with high accuracy and lower number of training parameters making it suitable for real clinical applications and continuous learning.

Suppression of motion artifacts in intravascular photoacoustic image sequences.

Intravascular photoacoustic (IVPA) imaging is an image-based imaging modality for the assessment of atherosclerotic plaques. Successful application of IVPA for in vivo coronary arterial imaging requires one overcomes the challenge of motion artifacts associated with the cardiac cycle. We propose a method for correcting artifacts owing to cardiac motion, which are observed in sequential IVPA images acquired by the continuous pullback of the imaging catheter. This method groups raw photoacoustic signals into subsets corresponding to similar phases in the cardiac cycles. Thereafter, the sequential images are reconstructed, by representing the initial pressure distribution on the vascular cross-sections based on the clustered frames of signals by time reversal. Results of simulation data demonstrate the efficacy of this method in suppressing motion artifacts. Qualitative and quantitative evaluations of the method indicate an enhancement of the image quality. Comparison results reveal that this method is computationally efficient in motion correction compared with the image-based gating.

The efficacy of three dimensional echocardiography in assessment of aortic atherosclerotic plaques compared to two dimensional echocardiography

Abstract Background Complex aortic atherosclerotic plaques (AAPs) carry a significant risk of embolism. Currently, two-dimensional (2D) transesophageal echocardiography (TEE) is the principal diagnostic tool of AAPs. However, we hypothesized that the data obtained from three-dimensional (3D) imaging may improve AAPs' spatial assessment. Purpose This study was aimed to evaluate the efficacy of 3DTEE in assessment of AAPs. Methods This study includes 96 patients who underwent routine TEE in our center within 2018–2019. The entire aorta including aortic root, ascending aorta, aortic arch, and descending thoracic aorta was investigated using both 2D and 3D TEE. The size and grade of aortic atherosclerotic plaques were compared using both 2D and 3D TEE. In addition, we examined to see if there is any correlation between the grade and size of the plaque, and patient's cardiac risk factors including their history of atherosclerotic diseases. Results Patients with atherosclerotic plaque in the ascending aorta had a larger plaque thickness in both two-dimensional and three-dimensional echocardiography. Obesity was an important risk factor for development of AAPs. Also, patients with a history of cerebrovascular attack (CVA) or transient ischemic attach (TIA) had larger AAPs. While age and gender showed no impact on the thickness of AAPs. According to the results obtained from comparing three-dimensional over two-dimensional echocardiography, one patient (1.04%) showed a decrease in grading scale, while nine patients (9.38%) showed enhancement in their grading (P-value=0.03). For the rest of 86 patients (89.58), atherosclerotic plaque grading was similar using both methods. This means that in almost 9% of cases 3D TEE increases the grading of the attributed atherosclerotic plaque, while it is the same to 2DTEE in most cases. Conclusions The information obtained from three-dimensional echocardiography would be most often very similar to the two-dimensional echocardiography, while in few cases, it would improve the grading scale. Cases with obesity and history of CVA and TIA had larger thickness of AAPs in both 2D and 3DTEE, while age and gender had no impact on plaque thickness. Funding Acknowledgement Type of funding sources: None.