Expansive arterial remodeling of the carotid arteries and its effect on atherosclerotic plaque composition and vulnerability: an in-vivo black-blood 3T CMR study in symptomatic stroke patients

A 3D framework for segmentation of carotid artery vessel wall and identification of plaque compositions in multi-sequence MR images

Accurately assessing carotid artery wall thickening and identifying risky plaque components are critical for early diagnosis and risk management of carotid atherosclerosis. In this paper, we present a 3D framework for automated segmentation of the carotid artery vessel wall and identification of the compositions of carotid plaque in multi-sequence magnetic resonance (MR) images under the challenge of imperfect manual labeling. Manual labeling is commonly done in 2D slices of these multi-sequence MR images and often lacks perfect alignment across 2D slices and the multiple MR sequences, leading to labeling inaccuracies. To address such challenges, our framework is split into two parts: a segmentation subnetwork and a plaque component identification subnetwork. Initially, a 2D localization network pinpoints the carotid artery's position, extracting the region of interest (ROI) from the input images. Following that, a signed-distance-map-enabled 3D U-net (Çiçek etal, 2016)an adaptation of the nnU-net (Ronneberger and Fischer, 2015) segments the carotid artery vessel wall. This method allows for the concurrent segmentation of the vessel wall area using the signed distance map (SDM) loss (Xue et al., 2020) which regularizes the segmentation surfaces in 3D and reduces erroneous segmentation caused by imperfect manual labels. Subsequently, the ROI of the input images and the obtained vessel wall masks are extracted and combined to obtain the identification results of plaque components in the identification subnetwork. Tailored data augmentation operations are introduced into the framework to reduce the false positive rate of calcification and hemorrhage identification. We trained and tested our proposed method on a dataset consisting of 115 patients, and it achieves an accurate segmentation result of carotid artery wall (0.8459 Dice), which is superior to the best result in published studies (0.7885 Dice). Our approach yielded accuracies of 0.82, 0.73 and 0.88 for the identification of calcification, lipid-rich core and hemorrhage components. Our proposed framework can be potentially used in clinical and research settings to help radiologists perform cumbersome reading tasks and evaluate the risk of carotid plaques.

Plaque Evolution and Vessel Wall Remodeling of Intracranial Arteries: A Prospective, Longitudinal Vessel Wall MRI Study

BACKGROUND

Progression of intracranial atherosclerotic disease (ICAD) is associated with ischemic stroke events and can be quantified with three-dimensional (3D) intracranial vessel wall (IVW) MRI. However, longitudinal 3D IVW studies are limited and ICAD evolution remains relatively unknown.

PURPOSE

To evaluate ICAD changes longitudinally and to characterize the imaging patterns of atherosclerotic plaque evolution.

STUDY TYPE

Prospective.

POPULATION

37 patients (69 ± 12 years old, 12 females) with angiography confirmed ICAD.

FIELD STRENGTH/SEQUENCE

3.0T/3D time-of-flight gradient echo sequence and T1- and proton density-weighted fast spin echo sequences.

ASSESSMENT

Each patient underwent baseline and 1-year follow-up IVW. Then, IVW data from both time points were jointly preprocessed using a multitime point, multicontrast, and multiplanar viewing workflow (known as MOCHA). Lumen and outer wall of plaques were traced and measured, and plaques were then categorized into progression, stable, and regression groups based on changes in plaque wall thickness. Patient demographic and clinical data were collected. Culprit plaques were identified based on cerebral ischemic infarcts.

STATISTICAL TESTS

Generalized estimating equations-based linear and logistic regressions were used to assess associations between vascular risk factors, medications, luminal stenosis, IVW plaque imaging features, and longitudinal changes. A two-sided P-value<0.05 was considered statistically significant.

RESULTS

Diabetes was significantly associated with ICAD progression, resulting in 6.6% decrease in lumen area and 6.7% increase in wall thickness at 1-year follow-up. After accounting for arterial segments, baseline contrast enhancement predicted plaque progression (odds ratio = 3.61). Culprit plaques experienced an average luminal expansion of 10.9% after 1 year. 74% of the plaques remained stable during follow-up. The regression group (18 plaques) showed significant increase in minimum lumen area (from 7.4 to 8.3 mm2 ), while the progression group (13 plaques) showed significant decrease in minimum lumen area (from 5.4 to 4.3 mm2 ).

DATA CONCLUSION

Longitudinal 3D IVW showed ICAD remodeling on the lumen side. Culprit plaques demonstrated longitudinal luminal expansion compared with their non-culprit counterparts. Baseline plaque contrast enhancement and diabetes mellitus were found to be significantly associated with ICAD changes.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 3.

Challenges and Pitfalls in CT-Angiography Evaluation of Carotid Bulb Stenosis: Is It Time for a Reappraisal?

We aimed to perform an anatomical evaluation of the carotid bulb using CT-angiography, implement a new reliable index for carotid stenosis quantification and to assess the accuracy of relationship between NASCET and ECST methods in a large adult population. The cross-sectional areas of the healthy carotid at five levels were measured by two experienced radiologists. A regression analysis was performed in order to quantify the relationship between the areas of the carotid bulb at different carotid bulbar level. A new index (Regression indeX, RegX) for carotid stenosis quantification was proposed. Five different stenoses with different grade in three bulbar locations were simulated for all patients for a total of 1365 stenoses and were used for a direct comparison of the RegX, NASCET, and ECST methods. The results of this study demonstrated that the RegX index provided a consistent and accurate measure of carotid stenosis through the application of the ECST method, avoiding the limitations of NASCET method. Furthermore, our results strongly depart from the consolidated relationships between NASCET and ECST values used in clinical practice and reported in extensive medical literature. In particular, we highlighted that a major misdiagnosis in patient selection for CEA could be introduced because of the large underestimation of real stenosis degree provided by the NASCET method. A reappraisal of carotid stenosis patients' work-up is evoked by the effectiveness of state-of-the-art noninvasive contemporary carotid imaging.

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.

Identification Markers of Carotid Vulnerable Plaques: An Update

Vulnerable plaques have been a hot topic in the field of stroke and carotid atherosclerosis. Currently, risk stratification and intervention of carotid plaques are guided by the degree of luminal stenosis. Recently, it has been recognized that the vulnerability of plaques may contribute to the risk of stroke. Some classical interventions, such as carotid endarterectomy, significantly reduce the risk of stroke in symptomatic patients with severe carotid stenosis, while for asymptomatic patients, clinically silent plaques with rupture tendency may expose them to the risk of cerebrovascular events. Early identification of vulnerable plaques contributes to lowering the risk of cerebrovascular events. Previously, the identification of vulnerable plaques was commonly based on imaging technologies at the macroscopic level. Recently, some microscopic molecules pertaining to vulnerable plaques have emerged, and could be potential biomarkers or therapeutic targets. This review aimed to update the previous summarization of vulnerable plaques and identify vulnerable plaques at the microscopic and macroscopic levels.

Epigenetic Regulation of Vascular Smooth Muscle Cell Phenotype Switching in Atherosclerotic Artery Remodeling: A Mini-Review

Atherosclerosis is a chronic inflammatory disease characterized by extensive remodeling of medium and large-sized arteries. Inward remodeling (=lumen shrinkage) of the vascular walls is the underlying cause for ischemia in target organs. Therefore, inward remodeling can be considered the predominant feature of atherosclerotic pathology. Outward remodeling (=lumen enlargement) is a physiological response compensating for lumen shrinkage caused by neointimal hyperplasia, but as a pathological response to changes in blood flow, outward remodeling leads to substantial arterial wall thinning. Thinned vascular walls are prone to rupture, and subsequent thrombus formation accounts for the majority of acute cardiovascular events. Pathological remodeling is driven by inflammatory cells which induce vascular smooth muscle cells to switch from quiescent to a proliferative and migratory phenotype. After decades of intensive research, the molecular mechanisms of arterial remodeling are starting to unfold. In this mini-review, we summarize the current knowledge of the epigenetic and transcriptional regulation of vascular smooth muscle cell phenotype switching from the contractile to the synthetic phenotype involved in arterial remodeling and discuss potential therapeutic options.

Association between Intraplaque Hemorrhage and Vascular Remodeling in Carotid Arteries: The Plaque at RISK (PARISK) Study

INTRODUCTION

Vascular remodeling is a compensatory enlargement of the vessel wall in response to atherosclerotic plaque growth. We aimed to investigate the association between intraplaque hemorrhage (IPH), vascular remodeling, and luminal dimensions in recently symptomatic patients with mild to moderate carotid artery stenosis in which the differences in plaque size were taken into account.

MATERIALS AND METHODS

We assessed vessel dimensions on MRI of the symptomatic carotid artery in 164 patients from the Plaque At RISK study. This study included patients with recent ischemic neurological event and ipsilateral carotid artery stenosis <70%. The cross section with the largest wall area (WA) in the internal carotid artery (ICA) was selected for analysis. On this cross section, the following parameters were determined: WA, total vessel area (TVA), and lumen area (LA). Vascular remodeling was quantified as the remodeling ratio (RR) and was calculated as TVA at this position divided by the TVA in an unaffected distal portion of the ipsilateral ICA. Adjustment for WA was performed to correct for plaque size.

RESULTS

Plaques with IPH had a larger WA (0.56 vs. 0.46 cm2; p < 0.001), a smaller LA (0.17 vs. 0.22 cm2; p = 0.03), and a higher RR (2.0 vs. 1.9; p = 0.03) than plaques without IPH. After adjustment for WA, plaques containing IPH had a smaller LA (B = -0.052, p = 0.01) than plaques without IPH, but the RR was not different.

CONCLUSION

After correcting for plaque size, plaques containing IPH had a smaller LA than plaques without IPH. However, RR was not different.

Hypoxia and its preconditioning on cardiac and vascular remodelling in experimental animals

Since oxygen (O₂) is indispensable for mammalian life, every cell in the body is endowed with mechanisms to detect and to respond to changes in the O₂ levels in the microenvironment. The heart and the brain are the two most vital, life-supporting organs requiring a continuous supply of O₂ to sustain their high metabolic rate. On being challenged with hypoxia, maintenance of O₂ supply to these organs even at the cost of others becomes a priority. This review describes the cardiovascular, skeletal muscle vascular, pulmonary vascular and cerebrovascular remodelling in face of chronic mild hypoxia exposure and the underlying mechanisms, with special reference to the role of oxidative stress, hypoxia signalling, autonomic nervous mechanisms. The significance of the normalized wall index (NWI) in assessing the remodelling of the vessels particularly of the intramyocardial coronary artery has been underscored. The review also highlights the basic concepts of hypoxic preconditioning and the subsequent protection of the brain against an acute ischemic insult in preclinical studies hinting towards its possible therapeutic potential in the management of ischemic stroke.

Severe, recurrent in-stent carotid restenosis: endovascular approach, risk factors. Results from a prospective academic registry of 2637 consecutive carotid artery stenting procedures (TARGET-CAS)

Introduction

Optimal management of severe carotid in-stent restenosis remains unknown. Prevalence and risk factors of first and recurrent carotid in-stent restenosis in the multi-stent approach have not been established yet.

Aim

To evaluate the safety of different methods of endovascular treatment of carotid in-stent restenosis/recurrent restenosis and to establish its rate and risk factors.

Material and methods

Between January 2001 and June 2016, 2637 neuroprotected carotid artery stenting (CAS) procedures were performed in 2443 patients (men: 67.0%; mean age: 67.9 ±8.8 years, symptomatic: 45.5%). Doppler ultrasound (DUS) evaluation was performed at discharge, after 3-6 months, 12 months, and then annually. Peak systolic velocity of 2-3 and > 3.0 m/s as well as end diastolic velocity of 0.5-0.9 and > 0.9 m/s were DUS criteria for 50-69% and ≥ 70% carotid in-stent restenosis (ISR) respectively. For angiographically confirmed ≥ 70% stenosis balloon re-angioplasty was first line treatment.

Results

Out of 95 DUS detected > 50% ISR (95/2637; 3.6%), 53 were confirmed in angiography as ≥ 70% (53/2637; 2.0%, one total occlusion). All patients were treated with bare balloon (n = 19), drug-eluting balloon (n = 27) or stent-supported (n = 6) angioplasty. One procedure was complicated with stroke (1.9%). Angiographic diameter stenosis (DS) was reduced from 83 ±8.3% to 13 ±7.6% (p < 0.001). There were 13 cases of ≥ 70% recurrent ISR. Bilateral and high-grade stenosis were independent risk factors of restenosis. Initial Carotid Wallstent implantation was a risk factor of first and recurrent in-stent restenosis.

Conclusions

Endovascular treatment of carotid in-stent restenosis is safe. Bilateral and high-grade carotid artery stenosis may increase the risk of restenosis. Initial Carotid Wallstent implantation may increase the risk of first and recurrent restenosis.

Expansive carotid artery remodeling: possible marker of vulnerable plaque

OBJECTIVE

Accumulated findings in the pathophysiology of atherosclerosis have demonstrated that not only luminal narrowing but also plaque characteristics influence the risk of future ischemic events. The morphology of the carotid artery (CA) changes in response to atherosclerotic development by expansive remodeling (ER), the clinical significance of which remains unclear. This study aimed to define associations between ER and local risk factors, including CA geometry and traditional systemic risk factors for ischemic events, to determine whether ER could serve as a clinical marker of carotid vulnerable plaque.

METHODS

The authors retrospectively analyzed 66 patients with CA stenosis who were scheduled to undergo carotid endarterectomy or CA stenting. They calculated ER ratios in the internal CA (ICA) from long-axis MR images and as the maximal distance between the lumen and the outer borders of the plaque perpendicular to the axis of the ICA/the maximal luminal diameter of the distal ICA at a region unaffected by atherosclerosis. Relative overall signal intensity (roSI) was calculated to assess intraplaque hemorrhage and defined as the signal intensity of plaque on an axial T1-weighted image with maximal stenosis relative to that of the adjacent sternocleidomastoid muscle. The authors evaluated CA geometry by calculating the angles between the common CA (CCA) and ICA, and between the CCA and external CA (ECA) using digital subtraction angiography. The ER ratios, age, sex, percentage of stenosis, roSI, hypertension, hyperlipidemia, low-density lipoprotein, statin medication, diabetes, smoking habit, and ischemic heart disease were compared between 33 symptomatic and 33 asymptomatic patients. The authors also compared symptomatic status, age, sex, percentage of stenosis, ICA angle, ECA angle, roSI, and other traditional atherosclerotic risk factors between groups with extensive and slight ER.

RESULTS

The ER ratio was significantly greater in symptomatic than in asymptomatic patients (1.91 ± 0.46 vs 1.68 ± 0.40, p < 0.05). The ICA angle was significantly larger in the group with extensive ER than in those with slight ER (33.9° ± 20.2° vs 21.7° ± 13.8°, p < 0.01). The roSI, ECA angle, percentage stenosis, or any other traditional vascular risk factors were not associated with ER.

CONCLUSIONS

Carotid ER might be an independent indicator of carotid vulnerable plaque, which should be validated in a longitudinal study of patients with carotid atherosclerosis, including those with nonstenotic to moderate stenosis.

Four Different Carotid Atherosclerotic Behaviors Based on Luminal Stenosis and Plaque Characteristics in Symptomatic Patients: An in Vivo Study

Correct stratification of ischemic stroke risk allows for the proper treatment of carotid atherosclerotic disease. We seek to differentiate plaque types based on stenosis level and plaque morphology. The Chinese Atherosclerosis Risk Evaluation (CARE-II) study is a cross-sectional, observational, multicenter study to assess carotid atherosclerotic plaques in symptomatic subjects using vessel wall magnetic resonance imaging. Plaque morphology and presence of plaque components were reviewed using multi-contrast magnetic resonance imaging. The carotid arteries were divided into four groups based on stenosis level and plaque components. Out of 1072 ischemic stroke subjects, 452 ipsilateral side carotid arteries were included. Significant stenosis (SS) (≥50% stenosis) with high-risk plaque (HRP) features was present in 37 arteries (8.2%), SS(+)/HRP(-) in 29 arteries (6.4%), SS(-)/HRP(+) in 57 arteries (12.6%), and SS(-)/HRP(-) in 329 arteries (72.8%). The prevalence of SS(-)/HRP(+) arteries in this cohort was substantial and had greater wall thickness than the SS(+)/HRP(-) group. These arteries may be misclassified for carotid revascularization by current guidelines based on the degree of luminal stenosis only. These findings have implications for further studies to assess stroke risk using vessel wall imaging.

Subclinical Atherosclerosis Imaging in People Living with HIV

In many, but not all studies, people living with HIV (PLWH) have an increased risk of coronary artery disease (CAD) events compared to the general population. This has generated considerable interest in the early, non-invasive detection of asymptomatic (subclinical) atherosclerosis in PLWH. Ultrasound studies assessing carotid artery intima-media thickness (CIMT) have tended to show a somewhat greater thickness in HIV+ compared to HIV−, likely due to an increased prevalence of cardiovascular (CV) risk factors in PLWH. Coronary artery calcification (CAC) determination by non-contrast computed tomography (CT) seems promising to predict CV events but is limited to the detection of calcified plaque. Coronary CT angiography (CCTA) detects calcified and non-calcified plaque and predicts CAD better than either CAC or CIMT. A normal CCTA predicts survival free of CV events over a very long time-span. Research imaging techniques, including black-blood magnetic resonance imaging of the vessel wall and 18F-fluorodeoxyglucose positron emission tomography for the assessment of arterial inflammation have provided insights into the prevalence of HIV-vasculopathy and associated risk factors, but their clinical applicability remains limited. Therefore, CCTA currently appears as the most promising cardiac imaging modality in PLWH for the evaluation of suspected CAD, particularly in patients <50 years, in whom most atherosclerotic coronary lesions are non-calcified.

Expansive arterial remodeling of carotid arteries in symptomatic ischemic patients

Purpose: The present study aimed to assess the associations of expansive remodeling of carotid arteries with ischemic symptoms and the degree of stenosis. Materials and Methods: A total of 41 symptomatic patients with vulnerable plaques and 25 asymptomatic individuals with stable plaques were included. All patients underwent 3.0T high-resolution MRI of the carotid artery (CA) for measuring the expansive remodeling (ER) ratio and assessing plaque stability. The ER ratio was calculated by dividing the maximum distance between the lumen and the outer border of the plaque in the internal CA by the lumen diameter within 1 centimeter of the plaque at the distal ipsilateral internal CA. ER ratios were compared between the symptomatic and asymptomatic groups. The 41 symptomatic patients were further divided into 4 groups according to stenosis rate (CA stenosis <50%, 50%-74%, 75-89%, and > 90%), and the correlation between the ER ratio and the rate of stenosis was evaluated. Results: There was a significant difference in ER ratio between the symptomatic and asymptomatic groups (p<0.001). When symptomatic patients were divided into 4 subgroups based on degree of stenosis, ER ratios among groups showed statistically significant differences (p=0.014). Conclusion: There were significant associations of the ER ratio with ischemic symptoms. Furthermore, the ER ratio in symptomatic patients continued to increase with stenosis severity. These findings suggested that the ER ratio might be a practical marker of plaque vulnerability in the CA and further prospective studies for asymptomatic patients are warranted.

LncRNA MIAT sponges miR-149-5p to inhibit efferocytosis in advanced atherosclerosis through CD47 upregulation

Atherosclerotic cardio-cerebrovascular disease and death remain the leading cause of morbidity and mortality worldwide. Defective efferocytosis, the clearance of apoptotic cells by macrophages, is thought to lead to increased inflammation and necrotic core formation in atherosclerotic lesions. However, very little is known about the role of long noncoding RNA (lncRNA) during this process. Here we show that lncRNA myocardial infarction associated transcript (MIAT) was markedly elevated in the serum of patients with symptoms of vulnerable atherosclerotic plaque and the macrophages of necrotic cores in an advanced atherosclerosis mouse model. MIAT knockdown attenuated atherosclerosis progression, reduced necrotic core size, and increased plaque stability in vivo. Furthermore, MIAT knockdown promoted clearance of apoptotic cells by macrophages in vivo and in vitro. Mechanistic studies revealed that MIAT acted as a micro RNA (miRNA) sponge to positively modulate the expression of anti-phagocytic molecule CD47 through sponging miR-149-5p. Together, these findings identified a macrophage MIAT/miR-149-5p /CD47 pathway as a key factor in the development of necrotic atherosclerotic plaques.

Journal of Cardiovascular Magnetic Resonance 2017

There were 106 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2017, including 92 original research papers, 3 reviews, 9 technical notes, and 1 Position paper, 1 erratum and 1 correction. The volume was similar to 2016 despite an increase in manuscript submissions to 405 and thus reflects a slight decrease in the acceptance rate to 26.7%. The quality of the submissions continues to be high. The 2017 JCMR Impact Factor (which is published in June 2018) was minimally lower at 5.46 (vs. 5.71 for 2016; as published in June 2017), which is the second highest impact factor ever recorded for JCMR. The 2017 impact factor means that an average, each JCMR paper that were published in 2015 and 2016 was cited 5.46 times in 2017.In accordance with Open-Access publishing of Biomed Central, the JCMR articles are published on-line in continuus fashion and in the chronologic order of acceptance, with no collating of the articles into sections or special thematic issues. For this reason, over the years, the Editors have felt that it is useful to annually summarize the publications into broad areas of interest or theme, so that readers can view areas of interest in a single article in relation to each other and other contemporary JCMR articles. In this publication, the manuscripts are presented in broad themes and set in context with related literature and previously published JCMR papers to guide continuity of thought within the journal. In addition, I have elected to use this format to convey information regarding the editorial process to the readership.I hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your very best, high quality manuscripts to JCMR for consideration. I thank our very dedicated Associate Editors, Guest Editors, and Reviewers for their efforts to ensure that the review process occurs in a timely and responsible manner and that the JCMR continues to be recognized as the forefront journal of our field. And finally, I thank you for entrusting me with the editorship of the JCMR as I begin my 3rd year as your editor-in-chief. It has been a tremendous learning experience for me and the opportunity to review manuscripts that reflect the best in our field remains a great joy and highlight of my week!

Carotid Artery Remodeling Is Segment Specific: An In Vivo Study by Vessel Wall Magnetic Resonance Imaging

OBJECTIVE

Early atherosclerosis is often undetected due in part to compensatory enlargement of the outer wall, termed positive remodeling. Variations in hemodynamic conditions and clinical factors influence the patterns of remodeling. The carotid artery provides an opportunity to examine these variations because of the unique geometry of the carotid bulb. This study aimed to determine differences in remodeling of the common, internal, and bifurcation segments of the carotid using magnetic resonance imaging.

APPROACH AND RESULTS

Carotid arteries of 525 subjects without history of cardiovascular disease were imaged by magnetic resonance imaging. The carotid artery was divided into 3 segments: common carotid artery; bifurcation; and internal carotid artery. Remodeling patterns were characterized using linear regression analysis of lumen and total vessel areas (dependent variables) compared with maximum wall thickness (independent variable) for each segment, adjusted for age, sex, and height. The common carotid artery demonstrated a pattern consistent with positive remodeling, whereas the bifurcation demonstrated negative remodeling. The internal carotid artery demonstrated a mixed pattern of outer wall expansion and lumen constriction. Females and subjects with diabetes mellitus showed more positive remodeling, hypertension was associated with attenuated positive remodeling, and those with hypercholesterolemia showed more negative remodeling.

CONCLUSIONS

In this cohort of 55- to 80-year-old individuals without history of cardiovascular disease, the pattern of early carotid artery remodeling was segment specific and appeared to be associated with sex and clinical characteristics. These findings provide the groundwork for longitudinal studies to define local and systemic factors such as hemodynamic and clinical conditions on carotid artery remodeling.

Review of Journal of Cardiovascular Magnetic Resonance (JCMR) 2015-2016 and transition of the JCMR office to Boston

The Journal of Cardiovascular Magnetic Resonance (JCMR) is the official publication of the Society for Cardiovascular Magnetic Resonance (SCMR). In 2016, the JCMR published 93 manuscripts, including 80 research papers, 6 reviews, 5 technical notes, 1 protocol, and 1 case report. The number of manuscripts published was similar to 2015 though with a 12% increase in manuscript submissions to an all-time high of 369. This reflects a decrease in the overall acceptance rate to <25% (excluding solicited reviews). The quality of submissions to JCMR continues to be high. The 2016 JCMR Impact Factor (which is published in June 2016 by Thomson Reuters) was steady at 5.601 (vs. 5.71 for 2015; as published in June 2016), which is the second highest impact factor ever recorded for JCMR. The 2016 impact factor means that the JCMR papers that were published in 2014 and 2015 were on-average cited 5.71 times in 2016.In accordance with Open-Access publishing of Biomed Central, the JCMR articles are published on-line in the order that they are accepted with no collating of the articles into sections or special thematic issues. For this reason, over the years, the Editors have felt that it is useful to annually summarize the publications into broad areas of interest or themes, so that readers can view areas of interest in a single article in relation to each other and other recent JCMR articles. The papers are presented in broad themes with previously published JCMR papers to guide continuity of thought in the journal. In addition, I have elected to open this publication with information for the readership regarding the transition of the JCMR editorial office to the Beth Israel Deaconess Medical Center, Boston and the editorial process.Though there is an author publication charge (APC) associated with open-access to cover the publisher's expenses, this format provides a much wider distribution/availability of the author's work and greater manuscript citation. For SCMR members, there is a substantial discount in the APC. I hope that you will continue to send your high quality manuscripts to JCMR for consideration. Importantly, I also ask that you consider referencing recent JCMR publications in your submissions to the JCMR and elsewhere as these contribute to our impact factor. I also thank our dedicated Associate Editors, Guest Editors, and reviewers for their many efforts to ensure that the review process occurs in a timely and responsible manner and that the JCMR continues to be recognized as the leading publication in our field.

Smaller outer diameter of atherosclerotic middle cerebral artery associated with RNF213 c.14576G>A Variant (rs112735431)

Background:

Intracranial atherosclerosis (ICAS) involves diverse histologies and several remodeling patterns. Ring finger protein 213 (RNF213) c.14576G>A variant (rs112735431), recently reported to be associated with ICAS, may be linked with negative remodeling (outer diameter – reducing morphological alteration) of intracranial arteries. This study investigated the outer diameter of atherosclerotic middle cerebral artery (MCA).

Methods:

Patients with unilateral atherosclerotic MCA stenosis/occlusion were enrolled in this single-hospital-based case-control study at The University of Tokyo Hospital. The patients were divided into two groups by the presence of RNF213 c.14576G>A (variant group and wild-type group) and the outer diameter of the MCA was measured with high-resolution magnetic resonance imaging.

Results:

Twenty-eight patients with the wild type and 19 patients with the variant type were included. The outer diameter of the stenotic side MCA was smaller in the variant group than in the wild-type group (P = 8.3 × 10^-6). The outer diameter of the normal side MCA was also smaller in the variant group than in the wild-type group (P = 5.2 × 10^-3). The ratio of stenotic side to normal side was also smaller in the variant group than in the wild-type group (P = 1.5 × 10^-5).

Conclusions:

This study indicates that RNF213 c.14576G>A is associated with negative remodeling of ICAS.

Evaluation of carotid plaque vulnerability in vivo: Correlation between dynamic contrast-enhanced MRI and MRI-modified AHA classification

PURPOSE

To noninvasively monitor carotid plaque vulnerability by exploring the relationship between pharmacokinetic parameters (PPs) of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and plaque types based on MRI-modified American Heart Association (AHA) classification, as well as to assess the ability of PPs in discrimination between stable and vulnerable plaques suspected on MRI.

MATERIALS AND METHODS

Of 70 consecutive patients with carotid plaques who volunteered for 3.0T MRI (3D time-of-flight [TOF], T₁ -weighted, T₂ -weighted, 3D magnetization-prepared rapid acquisition gradient-echo [MP-RAGE] and DCE-MRI), 66 participants were available for analysis. After plaque classification according to MRI-modified AHA Lesion-Type (LT), PPs (K^trans , k_ep , v_e , and v_p ) of DCE-MRI were measured. The Extended Tofts model was used for calculation of PPs. For participants with multiple carotid plaques, the plaque with the worst MRI-modified AHA LT was chosen for analysis. Correlations between PPs and plaque types and the ability of these parameters to distinguish stable and vulnerable plaques suspected on MRI were assessed.

RESULTS

Significant positive correlation between K^trans and LT III to VI was found (ρ = 0.532, P < 0.001), as was the correlation between k_ep and LT III to VI (ρ = 0.409, P < 0.001). Stable and vulnerable plaques suspected on MRI could potentially be distinguished by K^trans (sensitivity 83%, specificity 100%) and k_ep (sensitivity 77%, specificity 91%).

CONCLUSION

K^trans and k_ep from DCE-MRI can provide quantitative information to monitor plaque vulnerability in vivo and differentiate vulnerable plaques suspected on MRI from stable ones. These two parameters could be adopted as imaging biomarkers for plaque characterization and risk stratification.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:870-876.