Magnetic resonance coronary angiography in the era of multimodality imaging.

Cardiovascular magnetic resonance is currently the reference standard for non-invasive measurements of ventricular dimensions and ejection fraction, and may offer a comprehensive assessment of all myocardial tissue properties (including oedema, fibrosis, fat, iron, and protein deposition), as well as of stress perfusion, conveniently as part of a single examination. It also has a well-established role for coronary assessment in paediatric patients, especially with congenital heart disease and vasculitides, such as Kawasaki disease, and it should be considered as a first-line technique in these cases. Despite being recognised as a safe, non-radiating, and non-contrast technique, it is yet to be implemented widely in clinical use as an efficient alternative to computed tomography coronary angiography. Currently impressive progress is being made in the development of sequences and overcoming technical challenges, which are thoroughly discussed in this article, while further development is required to convert this into a robust, non-invasive technique for routine clinical decision-making in cardiovascular disease, particularly in adult patients. In this review, we will summarise current clinical applications of magnetic resonance coronary imaging, both in adult and paediatric populations, with reference to currently established imaging techniques, focusing also on ongoing research and future development.

Comprehensive mitral valve prolapse assessment by cardiovascular MRI.

Mitral valve (MV) prolapse (MVP) is a not fully understood common MV disorder. The development of sophisticated cardiovascular magnetic resonance imaging (CMRI) sequences over the last decades has allowed a more detailed assessment and provided better understanding of the pathophysiology of MVP to guide management, interventions, and risk stratification of patients affected. This review provides an overview of the most recent insights about this multifaceted pathology, particularly regarding the emerging concepts of mitral annular disjunction (MAD), and risk of arrhythmia and sudden death associated with myocardial fibrosis. We describe the emerging role of CMRI in both diagnosis and, more importantly, risk assessment of this disease, aiming to provide a comprehensive protocol for the assessment of MVP, which could represent a practical guide to clinicians and MRI practitioners working in the field.

Hypertrophic Cardiomyopathy with a Twist.

Hypertrophic cardiomyopathy is a relatively common inherited cardiac disorder, with echocardiography still being the initial imaging method for its diagnosis. Cardiac fibroma is a primary neoplasm that most commonly presents in childhood. We present a patient who was investigated for typical cardiac symptoms who went on to have cardiac magnetic resonance imaging and was found to have both of these conditions.

The emerging applications of cardiovascular magnetic resonance imaging in transcatheter aortic valve implantation.

Transcatheter aortic valve implantation (TAVI) is an alternative to surgical aortic valve replacement in selected patients with severe symptomatic aortic stenosis (AS) and high surgical risk. The planning and follow-up of TAVI requires an array of imaging techniques, each has advantages and limitations. Echocardiography and multidetector computer tomography (MDCT) have established applications in patient selection and procedure guidance, but are limited in some patients. TAVI applications of cardiovascular magnetic resonance imaging (CMRI) are emerging. CMRI can provide the structural and functional imaging details required for TAVI procedure in away comparable or superior to that obtained by echocardiography and MDCT combined. In this review, we look at the continuously evolving role of CMRI as a complimentary or an alternative to more established imaging techniques and address the advantages and disadvantages of CMRI in this setting. We discuss the role of CMRI in selecting anatomically suitable patients for the TAVI procedure and in the post-TAVI follow-up with particular emphasis on its applications for assessing AS severity and haemodynamic impact, vascular imaging for TAVI access route, quantification of paravalvular leaks and LV remodelling in the post TAVI setting as well as providing imaging biomarkers tool for AS risk-stratification.

T2 mapping and T2* imaging in heart failure.

Cardiovascular magnetic resonance (CMR) is a versatile imaging modality that enables aetiological assessment and provides additional information to that of standard echocardiography in a significant proportion of patients with heart failure. In addition to highly accurate and reproducible assessment of ventricular volumes and replacement fibrosis, multiparametric mapping techniques have rapidly evolved to further expand the diagnostic and prognostic applications in various conditions ranging from acute inflammatory and ischaemic cardiomyopathy, to cardiac involvement in systemic diseases such as sarcoidosis and iron overload cardiomyopathy. In this review, we discuss the established role of T2* imaging and rapidly evolving clinical applications of myocardial T2 mapping as quantitative adjuncts to established qualitative imaging techniques.

Review of Journal of Cardiovascular Magnetic Resonance 2015.

There were 116 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2015, which is a 14 % increase on the 102 articles published in 2014. The quality of the submissions continues to increase. The 2015 JCMR Impact Factor (which is published in June 2016) rose to 5.75 from 4.72 for 2014 (as published in June 2015), which is the highest impact factor ever recorded for JCMR. The 2015 impact factor means that the JCMR papers that were published in 2013 and 2014 were cited on average 5.75 times in 2015. The impact factor undergoes natural variation according to citation rates of papers in the 2 years following publication, and is significantly influenced by highly cited papers such as official reports. However, the progress of the journal's impact over the last 5 years has been impressive. Our acceptance rate is <25 % and has been falling because the number of articles being submitted has been increasing. In accordance with Open-Access publishing, the JCMR articles go on-line as they are accepted with no collating of the articles into sections or special thematic issues. For this reason, the Editors have felt that it is useful once per calendar year to summarize the papers for the readership into broad areas of interest or theme, so that areas of interest can be reviewed in a single article in relation to each other and other recent JCMR articles. The papers are presented in broad themes and set in context with related literature and previously published JCMR papers to guide continuity of thought in the journal. We hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your quality papers to JCMR for publication.

Effects of aortic root motion on wall stress in the Marfan aorta before and after personalised aortic root support (PEARS) surgery.

Aortic root motion was previously identified as a risk factor for aortic dissection due to increased longitudinal stresses in the ascending aorta. The aim of this study was to investigate the effects of aortic root motion on wall stress and strain in the ascending aorta and evaluate changes before and after implantation of personalised external aortic root support (PEARS). Finite element (FE) models of the aortic root and thoracic aorta were developed using patient-specific geometries reconstructed from pre- and post-PEARS cardiovascular magnetic resonance (CMR) images in three Marfan patients. The wall and PEARS materials were assumed to be isotropic, incompressible and linearly elastic. A static load on the inner wall corresponding to the patients' pulse pressure was applied. Cardiovascular MR cine images were used to quantify aortic root motion, which was imposed at the aortic root boundary of the FE model, with zero-displacement constraints at the distal ends of the aortic branches and descending aorta. Measurements of the systolic downward motion of the aortic root revealed a significant reduction in the axial displacement in all three patients post-PEARS compared with its pre-PEARS counterparts. Higher longitudinal stresses were observed in the ascending aorta when compared with models without the root motion. Implantation of PEARS reduced the longitudinal stresses in the ascending aorta by up to 52%. In contrast, the circumferential stresses at the interface between the supported and unsupported aorta were increase by up to 82%. However, all peak stresses were less than half the known yield stress for the dilated thoracic aorta.

Aortic flow patterns before and after personalised external aortic root support implantation in Marfan patients.

Implantation of a personalised external aortic root support (PEARS) in the Marfan aorta is a new procedure that has emerged recently, but its haemodynamic implication has not been investigated. The objective of this study was to compare the flow characteristics and hemodynamic indices in the aorta before and after insertion of PEARS, using combined cardiovascular magnetic resonance imaging (CMR) and computational fluid dynamics (CFD). Pre- and post-PEARS MR images were acquired from 3 patients and used to build patient-specific models and upstream flow conditions, which were incorporated into the CFD simulations. The results revealed that while the qualitative patterns of the haemodynamics were similar before and after PEARS implantation, the post-PEARS aortas had slightly less disturbed flow at the sinuses, as a result of reduced diameters in the post-PEARS aortic roots. Quantitative differences were observed between the pre- and post-PEARS aortas, in that the mean values of helicity flow index (HFI) varied by -10%, 35% and 20% in post-PEARS aortas of Patients 1, 2 and 3, respectively, but all values were within the range reported for normal aortas. Comparisons with MR measured velocities in the descending aorta of Patient 2 demonstrated that the computational models were able to reproduce the important flow features observed in vivo.

Review of Journal of Cardiovascular Magnetic Resonance 2014.

There were 102 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2014, which is a 6% decrease on the 109 articles published in 2013. The quality of the submissions continues to increase. The 2013 JCMR Impact Factor (which is published in June 2014) fell to 4.72 from 5.11 for 2012 (as published in June 2013). The 2013 impact factor means that the JCMR papers that were published in 2011 and 2012 were cited on average 4.72 times in 2013. The impact factor undergoes natural variation according to citation rates of papers in the 2 years following publication, and is significantly influenced by highly cited papers such as official reports. However, the progress of the journal's impact over the last 5 years has been impressive. Our acceptance rate is <25% and has been falling because the number of articles being submitted has been increasing. In accordance with Open-Access publishing, the JCMR articles go on-line as they are accepted with no collating of the articles into sections or special thematic issues. For this reason, the Editors have felt that it is useful once per calendar year to summarize the papers for the readership into broad areas of interest or theme, so that areas of interest can be reviewed in a single article in relation to each other and other recent JCMR articles. The papers are presented in broad themes and set in context with related literature and previously published JCMR papers to guide continuity of thought in the journal. We hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your quality papers to JCMR for publication.

Biomechanical properties of the Marfan's aortic root and ascending aorta before and after personalised external aortic root support surgery.

Marfan syndrome is an inherited systemic connective tissue disease which may lead to aortic root disease causing dilatation, dissection and rupture of the aorta. The standard treatment is a major operation involving either an artificial valve and aorta or a complex valve repair. More recently, a personalised external aortic root support (PEARS) has been used to strengthen the aorta at an earlier stage of the disease avoiding risk of both rupture and major surgery. The aim of this study was to compare the stress and strain fields of the Marfan aortic root and ascending aorta before and after insertion of PEARS in order to understand its biomechanical implications. Finite element (FE) models were developed using patient-specific aortic geometries reconstructed from pre and post-PEARS magnetic resonance images in three Marfan patients. For the post-PEARS model, two scenarios were investigated-a bilayer model where PEARS and the aortic wall were treated as separate layers, and a single-layer model where PEARS was incorporated into the aortic wall. The wall and PEARS materials were assumed to be isotropic, incompressible and linearly elastic. A static load on the inner wall corresponding to the patients' pulse pressure was applied. Results from our FE models with patient-specific geometries show that peak aortic stresses and displacements before PEARS were located at the sinuses of Valsalva but following PEARS surgery, these peak values were shifted to the aortic arch, particularly at the interface between the supported and unsupported aorta. Further studies are required to assess the statistical significance of these findings and how PEARS compares with the standard treatment.

Predictors of paravalvular aortic regurgitation following self-expanding Medtronic CoreValve implantation: the role of annulus size, degree of calcification, and balloon size during pre-implantation valvuloplasty and implant depth.

OBJECTIVES: We sought to investigate the role of balloon size during pre-implantation valvuloplasty in predicting AR and optimal Medtronic CoreValve (MCS) implantation depth. BACKGROUND: Paravalvular aortic regurgitation (AR) is common following MCS implantation. A number of anatomical and procedural variables have been proposed as determinants of AR including degree of valve calcification, valve undersizing and implantation depth. METHODS: We conducted a multicenter retrospective analysis of 282 patients who had undergone MCS implantation with prior cardiac CT annular sizing between 2007 and 2011. Native valve minimum (Dmin), maximum (Dmax) and arithmetic mean (Dmean) annulus diameters as well as agatston calcium score were recorded. Nominal and achieved balloon size was also recorded. AR was assessed using contrast angiography at the end of each procedure. Implant depth was measured as the mean distance from the nadir of the non- and left coronary sinuses to the distal valve frame angiographically. RESULTS: 29 mm and 26 mm MCS were implanted in 60% and 39% of patients respectively. The majority of patients (N=165) developed AR <2 following MCS implantation. AR ≥3 was observed in 16% of the study population. High agatston calcium score and Dmean were found to be independent predictors of AR ≥3 in multivariate analysis (P<0.0001). Nominal balloon diameter and the number of balloon inflations did not influence AR. However a small achieved balloon diameter-to-Dmean ratio (≤0.85) showed modest correlation with AR ≥3 (P=0.04). This observation was made irrespective of the degree of valve calcification. A small MCS size-to-Dmean ratio is also associated with AR ≥3 (P=0.001). A mean implantation depth of ≥8+2mm was also associated with AR ≥3. Implantation depth of ≥12 mm was associated with small MCS diameter-to-Dmean ratio and increased 30-day mortality. CONCLUSION: CT measured aortic annulus diameter and agatston calcium score remain important predictors of significant AR. Other procedural predictors include valve undersizing and low implantation depth. A small achieved balloon diameter-to-Dmean ratio might also predict AR ≥3. Our findings confirm that a small achieved balloon size during pre-implantation valvuloplasty predicts moderate-severe AR in addition to previously documented factors.

Prevalence and prognostic implication of restenosis or dilatation at the aortic coarctation repair site assessed by cardiovascular MRI in adult patients late after coarctation repair.

BACKGROUND: Cardiovascular magnetic resonance (CMR) is ideal for assessing patients with repaired aortic coarctation (CoA). Little is known on the relation between long-term complications of CoA repair as assessed by CMR and clinical outcome. We examined the prevalence of restenosis and dilatation at the repair site and the long-term outcome in patients with repaired CoA. METHODS AND RESULTS: CMR imaging and clinical data for adult CoA patients (247 patients aged 33.0 ± 12.8 years, 60% male), were analyzed. The diameter of the aorta at the repair site was measured on CMR and its ratio to the aortic diameter at the diaphragm (repair site-diaphragm ratio, RDR) was calculated. Restenosis (RDR≤70%) was present in 31% of patients (and significant in 9% [RDR<50%]), and dilatation (RDR>150%) in 13.0%. A discrete aneurysm at the repair site was observed in 9%. Restenosis was more likely after resection and end-end anastomosis, whereas dilatation after patch repair. Systemic hypertension was present in 69% of patients. Of the hypertensive patients, blood pressure (133 ± 20/73 ± 10 mm Hg) was well controlled in 93% with antihypertensive therapy. Mortality rate over a median length of 5.9 years was low (0.69% per year, 95% CI: 0.33-1.26), but significantly higher than age-matched healthy controls (standardised mortality ratio 2.86, CI 1.43-5.72, p<0.001). CONCLUSION: Restenosis or dilatation at the CoA repair site as assessed by CMR is not uncommon. Medium term survival remains good, however, albeit lower than in the general population. Life-long follow-up and optimal blood pressure control are likely to secure a good longer term outlook in these patients.

Review of Journal of Cardiovascular Magnetic Resonance 2009.

There were 56 articles published in the Journal of Cardiovascular Magnetic Resonance in 2009. The editors were impressed with the high quality of the submissions, of which our acceptance rate was about 40%. In accordance with open-access publishing, the articles go on-line as they are accepted with no collating of the articles into sections or special thematic issues. We have therefore chosen to briefly summarise the papers in this article for quick reference for our readers in broad areas of interest, which we feel will be useful to practitioners of cardiovascular magnetic resonance (CMR). In some cases where it is considered useful, the articles are also put into the wider context with a short narrative and recent CMR references. It has been a privilege to serve as the Editor of the JCMR this past year. 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 quality manuscripts to JCMR for publication.

Nonrigid image registration with subdivision lattices: application to cardiac MR image analysis.

In this paper we present a new methodology for cardiac motion tracking in tagged MRI using nonrigid image registration based on subdivision surfaces and subdivision lattices. We use two sets of registrations to do the motion tracking. First, a set of surface registrations is used to create and initially align the subdivision model of the left ventricle with short-axis and long-axis MR images. Second, a series of volumetric registrations are used to perform the motion tracking and to reconstruct the 4D cardiac motion field from the tagged MR images. The motion of a point in the myocardium over time is calculated by registering the images taken during systole to the set of reference images taken at end-diastole. Registration is achieved by optimizing the positions of the vertices in the base lattice so that the mutual information of the images being registered is maximized. The presented method is validated using a cardiac motion simulator and we also present strain measurements obtained from a group of normal volunteers.

Takayasu arteritis: role of cardiovascular magnetic imaging.

Takayasu arteritis (TA) is a primary arteritis of unknown cause that commonly affects the aorta and its main branches. Traditionally, X-ray contrast angiography has been the gold standard for diagnosis and review of this chronic disease but recent developments suggest that non-invasive imaging with multiplanar cardiovascular magnetic resonance imaging (CMR) and magnetic resonance angiography (MRA) have a number of advantages for use in routine care. This review utilises a series of cases referred for imaging at the Royal Brompton Hospital, London to illustrate these points of development.

Inter-study reproducibility of 3D volume selective fast spin echo sequence for quantifying carotid artery wall volume in asymptomatic subjects.

PURPOSE: To determine, in asymptomatic subjects, the inter-study reproducibility of a three-dimensional (3D) volume selective fast spin echo (FSE) cardiovascular magnetic resonance sequence for the assessment of carotid artery wall volume as a measure of atheroma burden. METHODS: Inter-study reproducibility was evaluated in 16 asymptomatic volunteers (10 male, 6 female). Both carotid arteries were scanned twice with a median inter-scan time of 5 days. The images were acquired in cross-section, and the total carotid arterial wall volume (TWV) was calculated by subtraction of the total carotid lumen volume from the total outer carotid vessel volume. RESULTS: The mean carotid T1-weighted TWV for the first and second scans was 828 and 821 mm(3), respectively (mean difference 7 mm(3), p=0.45). The standard deviation (S.D.) of the differences between the measurements was 38 mm(3) yielding an inter-study coefficient of variation of 4.6%. The time for each study was approximately 30 min. For the longitudinal evaluation of carotid atheroma burden with pharmacological intervention versus placebo, 32 subjects would enable a difference of 38 mm(3) to be detected with a significance level of 5% with 80% power. CONCLUSION: Volumetric analysis with carotid CMR in asymptomatic subjects using a 3D volume-selective FSE is time-efficient with good inter-study reproducibility, and is well suited for longitudinal studies of carotid atheroma with reasonable sample sizes.