Search

Background Cardiac involvement in patients with sarcoidosis is an independent predictor of mortality and associated with very poor prognosis. Inflammatory processes within the myocardium as well as subsequent fibrotic myocardial alterations may lead to diastolic dysfunction and at worst sudden death resulting from ventricular tachy-arrhythmias or conduction block. Diastolic dysfunction as a sign of left ventricular (LV) impairment can be assessed accurately by the measurement of early diastolic strain rate (EDSR). In this follow up study we performed cardiovascular magnetic resonance (CMR) feature tracking (FT) in patients with and without cardiac involvement of sarcoidosis in order to investigate its impact on systolic and especially diastolic function over time.

Background Characterizing myocardial mechanical properties is valuable in understanding cardiomyopathy with and without clinical heart failure (HF). We sought to examine the incremental value of strain assessment in patients with left ventricular systolic dysfunction without HF (LVSD), HF with reduced ejection fraction (HFrEF), LV diastolic dysfunction without HF (LVDD) and HF with preserved EF (HFpEF) during routine cardiac MR (CMR) evaluation.

Background Atrio-ventricular (AV) block is a common bradyarrhythmia in the elderly, but is a rare event in young or middle-aged adults, often leading to pacemaker implantation without further investigation, though underlying aetiology influences both treatment strategies and prognosis. Cardiovascular magnetic resonance (CMR) has the potential to identify an underlying aetiology for AV block, over and above transthoracic echocardiogram (TTE), which is offered as the first imaging technique. We sought to assess the diagnostic additive role of CMR in young and middle aged adults (18-60 years) with high-grade AV block and to determine which findings on CMR best predict clinical impact.

Background: The ingestion of food is known to increase mesenteric blood flow significantly. However, it remains unknown whether this increased flow demand to the intestine is compensated by an increase in total cardiac output (CO) alone, or by redistribution of blood flow from other organs, caused by changes in organ-specific vascular resistance. Non-invasive studies on the vascular response of small arteries have been scarce due to technical constraints, as conventional as well as MRI-based methods for non-invasive flow assessment are time-consuming and observer-dependent. We present a novel, comprehensive phenotyping model of the hemodynamic changes caused by the ingestion of a high-energy liquid meal, assessed by novel MRI sequences for the rapid assessment of small vessel blood flow.

Background A fundamental component of the CMR exam is contrast enhanced imaging, which is crucial for delineating diseased from normal tissue. Unfortunately, diseased tissue adjacent to vasculature often remains hidden since there is poor contrast between hyperenhanced tissue and bright blood-pool. Conventional black-blood double-IR methods are not a solution; these were not designed to function after contrast administration since they rely on the long native T1 of blood (~2s at 3T) and adequate blood flow within this time period. We introduce a novel Flow-Independent Dark-blood DeLayed Enhancement technique (FIDDLE) that allows visualization of tissue contrast-enhancement while suppressing blood-pool signal. We validate FIDDLE in an animal model of myocardial infarction (MI) and demonstrate feasibility in patients.

Methods 77 healthy volunteers with no known cardiovascular condition underwent CMR at 1.5T (Siemens, Avanto). Mid ventricular short axis native T1 maps by MOLLI (with T1* reconstruction in addition) and ShMOLLI were acquired. Hematocrit (Hct), iron profile and lipid profile were acquired immediately prior to the scan. CVI42 (Calgary, Canada) was used for analysis of the maps. A ROI was drawn in the blood pool on the MOLLI T1 map, avoiding papillary muscles and was copied on to the MOLLI T1* and ShMOLLI T1.

Results From August, 2010 to July, 2015, 45 children (median age 3.6 years, range 1.5 18.9 years) have undergone a Y-graft Fontan. In all 45 patients, echocardiography was unable to visualize the Y-arm connections to the branch PA’s. Thirty-nine patients underwent CMR a median of 9 days after Fontan (range 4-295 days), and 6 patients with pacemakers underwent CTA. Early in the experience, time resolved contrast enhanced magnetic resonance angiogram (CEMRA) provided the best spatial resolution for baffle evaluation (Figure 1a). In late 2013, our CMR protocol changed to include a blood pool Gadolinium contrast agent, Gadofosveset Trisodium. Subsequently, postcontrast, 3D, respiratory navigated, inversion recovery gradient echo imaging (3D IR GRE) provided superior spatial resolution for the final 19 children (Figure 1b). In one patient, thrombosis in the baffle was found. In 40 patients, some degree of stenosis was found in a Fontan baffle or branch PA, though most were mild (n = 27). Among those with moderate or severe stenosis, most occurred in the central PA, between the insertion of the bidirectional Glenn (BDG) and a Y-arm (n = 7). Phase contrast imaging and the time resolved CEMRA provided insights into Fontan hemodynamics. In 14 patients, inferior systemic venous return was affected by the BDG position and angulation, with competitive flow in either the left or right Y-arm resulting in asymmetric inferior systemic venous return to the branch PA’s (Figure 2). This finding was more pronounced in patients with central PA stenosis.

Background Studies about the safety of MRI exams for patients with pacemakers/ICDs at 1.5T have been reported [Nazarian S., et al. Annals of internal medicine 155.7 (2011): 415-424.]. Of most concern is possible heating of the lead-tips in contact with the myocardium. Little is known about the relative safety of 3T MRI exams for these patients and in vivo lead-tip heating data is difficult, if not impossible, to obtain. Our objective was to measure lead-tip heating directly in human cadavers with pacemakers/ICDs at both 3.0T and 1.5T.

Background Magnetic Resonance Imaging (MRI) is regarded as a non harming and non invasive imaging modality with superb tissue contrast and almost no side effects. Compared to other cross-sectional imaging modalities MRI does not use ionizing radiation. Recently however, strong magnetic fields as applied in clinical MRI scanners have been suspected to induce DNA double strand breaks in human lymphocytes.

Background In the intact circulation, changes in intrathoracic pressure and/or lung volume will simultaneously induce alterations in cardiac volumes, output, and contractility among other alterations [1]. In this study, we evaluate the impact of respiratory suspension on the computation of volume-based early peak filling rate (EPFR) to late peak filling rate (LPFR) ratio using peak velocitybased Doppler echo measured early peak velocity (E) to peak velocity during atrial contraction (A) measured at the tip of the mitral leaflets as the reference.

Results The 598 patients (age 59 ± 12 years, 20% female underwent stress CMR a median of 93 days (IQR: 41, 224 days) after coronary stenting with follow-up for 1.4 years (IQR: 0.6-2.7). Inducible perfusion defects were identified in 294 (49%) patients of whom 18 (6%) died during follow-up compared with 6 (2.0%) patients with no perfusion defects (p = 0.01). Of the 294 patients with perfusion defects, 70 (24%) were revascularised (PCI 55, CABG 27) of whom 5 (7%) died during follow-up compared with 13 (6%) who were not revascularised(p = 0.68). K-M survival analysis confirmed that revascularisation was unassociated with survival benefit, regardless of the severity of ischaemia (Figure 1).

Background Adverse outcomes are increasingly common in patients after the Fontan operation as they approach adulthood. Right ventricular (RV) morphology, ventricular dilation, and diminished ventricular strain have all been independently associated with death or heart transplant. The aim of this study was to assess the impact of ventricular morphology on ventricular stress/strain relationship in patients late after the Fontan operation using cardiac magnetic resonance (CMR).

Background Advanced cardiac magnetic resonance (CMR) acquisitions often require long scan durations that necessitate respiratory navigator gating. This is particularly important in children with limited ability to hold their breath. We hypothesized that visual feedback of diaphragm position using an interactive videogame during CMR would increase navigator efficiency and improve image quality in children.

Background Cardiac biomarkers have become increasingly important in cardiovascular disease. With the ability to detect focal and diffuse myocardial fibrosis, CMR is an important imaging biomarker. Diffuse myocardial fibrosis, reflected by increased extracellular volume (ECV), may underlie increased cardiovascular risk. ECV could provide a novel tool to evaluate the association myocardial-specific fibrosis and serum biomarkers. We hypothesized that ECV would correlate with known cardiovascular serum biomarkers in hypertensive heart disease.

Background CE-MRA following the injection of a gadolinium-based contrast agent (GBCA) bolus is widely used in clinical assessment of vascular dynamics and tissue perfusion (1,2). Although keyhole techniques with an increased number of central k-space updates further improved contrast kinetics information, spatial resolution remains limited. Alternatively applied view sharing approaches also result in prolonged temporal footprints with possible temporal blurring or reconstruction artifacts. Sparse, incoherent sampling approaches and iterative reconstruction techniques have proven successful particularly in dynamic MR imaging (3). We sought to evaluate the impact of iterative reconstruction techniques on dynamic contrast enhanced MRA of the thoracic aorta.

Background Recent studies have shown that echocardiography and MRI are often discordant when assessing the severity of mitral regurgitation (MR), with echocardiography often overestimating severity of mitral regurgitation compared to MRI (1). This is particularly true among patients who underwent mitral valve surgery based on echocardiographic assessment and the current ACC/AHA recommendations for valvular disease. These findings not only have potential impact on patient management it also has an impact on the healthcare costs associated with mitral valve surgery.

Out of hospital cardiac arrest survivors with inconclusive coronary angiogram: impact of cardiovascular magnetic resonance on clinical management and decision-making Anna Baritussio, Martina Perazzolo Marra, Amardeep Ghosh Dastidar, Jonathan Rodrigues, Alessandro Zorzi, Angela Susana, Alessandra Scatteia, Estefania De Garate, Giulia Mattesi, Julian Strange, Domenico Corrado, Chiara Bucciarelli-Ducci