Myocardial involvement in children with post-COVID multisystem inflammatory syndrome: a cardiovascular magnetic resonance based multicenter international study-the CARDOVID registry.

Background: Recent evidence shows an association between coronavirus disease 2019 (COVID-19) infection and a severe inflammatory syndrome in children. Cardiovascular magnetic resonance (CMR) data about myocardial injury in children are limited to small cohorts. The aim of this multicenter, international registry is to describe clinical and cardiac characteristics of multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19 using CMR so as to better understand the real extent of myocardial damage in this vulnerable cohort.

Paediatric multisystem inflammatory syndrome associated with COVID-19: filling the gap between myocarditis and Kawasaki?

Myocarditis and Kawasaki disease are common but usually distinct diseases in children. During the coronavirus pandemic (COVID-19), reports of a new form of myocarditis with clinical features of Kawasaki appeared. We investigated the place of this new disease in the spectrum encompassing Kawasaki disease and myocarditis.

Noninvasive fetal electrocardiography for the detection of fetal arrhythmias.

Objective: To assess whether noninvasive fetal electrocardiography (NI-FECG) enables the diagnosis of fetal arrhythmias.

Methods: A total of 500 echocardiography and NI-FECG recordings were collected from pregnant women during a routine medical visit in this multicenter study. All the cases with fetal arrhythmias (n = 12) and a matching number of control (n = 14) were used.

Isotropic Reconstruction of MR Images Using 3D Patch-Based Self-Similarity Learning.

Isotropic three-dimensional (3D) acquisition is a challenging task in magnetic resonance imaging (MRI). Particularly in cardiac MRI, due to hardware and time limitations, current 3D acquisitions are limited by low-resolution, especially in the through-plane direction, leading to poor image quality in that dimension. To overcome this problem, super-resolution (SR) techniques have been proposed to reconstruct a single isotropic 3D volume from multiple anisotropic acquisitions.

Myocardial volume change during cardiac cycle derived from three orthogonal systolic strains: towards a quality assessment of strains.

Background: The relative modification of the myocardial volume between end-systole and end-diastole ( ) has already been assessed with different methods and falls in a range of 0.9-0.97 (mean value = 0.

Isotropic 3D cardiac cine MRI allows efficient sparse segmentation strategies based on 3D surface reconstruction.

Purpose: Segmentation of cardiac cine MRI data is routinely used for the volumetric analysis of cardiac function. Conventionally, 2D contours are drawn on short-axis (SAX) image stacks with relatively thick slices (typically 8 mm). Here, an acquisition/reconstruction strategy is used for obtaining isotropic 3D cine datasets; reformatted slices are then used to optimize the manual segmentation workflow.

Adaptive step size LMS improves ECG detection during MRI at 1.5 and 3 T.

Objective: We describe a new real-time filter to reduce artefacts on electrocardiogram (ECG) due to magnetic field gradients during MRI. The proposed filter is a least mean square (LMS) filter able to continuously adapt its step size according to the gradient signal of the ongoing MRI acquisition.

Materials And Methods: We implemented this filter and compared it, within two databases (at 1.

Accuracy of subject-specific prediction of end-systolic time in MRI across a range of RR intervals.

Background: Prediction of End-Systole time is of utmost importance for cardiac MRI to correctly associate acquired k-space lines during reconstruction of cine acquisitions. This prediction is usually based on the patient's heart rate using Weissler's formula, which was calibrated by linear regression within a population and cannot account for individual variability.

Objective: We propose an automatic method to build a personalized model that better predicts end-systole.

Can MRI detect pulmonary hypertension in a population pre-selected by echocardiography?

Background The place of magnetic resonance imaging (MRI) in the assessment of pulmonary hypertension (PH) remains controversial. Several studies proposed to use MRI to assess pulmonary pressure but the level of proof is low. Purpose To evaluate the diagnostic power of cardiac MRI within a non-selected population of patients suspected of PH after an echocardiography.

Recreational scuba diving in patients with congenital heart disease: Time for new guidelines.

The number of recreational scuba divers is steadily increasing. In its latest recommendations, the French Federation of Undersea Studies and Sports listed congenital heart disease as a formal and final contraindication to scuba diving. On the other hand, with the progress made in their management, the prognosis and quality of life of patients with congenital heart diseases have improved considerably, enabling them to engage in physical and sports endeavours, which are known to confer general health and psychological benefits.

Design and Validation of a Novel MR-Compatible Sensor for Respiratory Motion Modeling and Correction.

Goal: A novel magnetic resonance (MR) compatible accelerometer for respiratory motion sensing (MARMOT) is developed as a surrogate of the vendors' pneumatic belts. We aim to model and correct respiratory motion for free-breathing thoracic-abdominal MR imaging and to simplify patient installation.

Methods: MR compatibility of MARMOT sensors was assessed in phantoms and its motion modeling/correction efficacy was demonstrated on 21 subjects at 3 T.

Comprehensive monitoring of cardiac remodeling with aortic stroke volume values provided by a phase-contrast MRI sequence.

Objectives: Blood pressure (BP) and its changes with antihypertensive therapy are key parameters when monitoring left ventricular (LV) remodeling. This dual cross-sectional and longitudinal MRI study aimed to determine whether this monitoring is enhanced by aortic stroke volume (SV) values provided by a phase-contrast sequence.

Methods: The study involved 334 MRI examinations from 247 study participants who had no significant cardiac disease (18-85 years old, 40% with hypertension) and among whom 48 had a 2-4-year MRI follow-up.

Quality control of cardiac MRI for tetralogy of Fallot: Combination of standard measurements and physiological analysis to detect invalid examinations.

Background: Cardiac magnetic resonance imaging (MRI) is the key examination for patients with tetralogy of Fallot, but it remains challenging. The MRI report should at least mention left (L) and right (R) ventricle end-diastole volumes (V), ejection fraction (EF) and pulmonary regurgitation (PR). These variables are linked by basic physiology rules and (V × EF)L=(V × EF)R(1-PR).

Specifics of cardiac magnetic resonance imaging in children.

This review points out three specific features of cardiac magnetic resonance imaging (MRI) in children: the small size of the heart modifies the usual balance between signal-to-noise ratio and spatial resolution; the higher and more variable heart rate limits tissue characterization and temporal resolution; and motion artefacts (notably respiratory motions) must be dealt with. In the second part of this review, we present the current and future practices of cardiac magnetic resonance (CMR) in children, based on the experience of all French paediatric cardiac MRI centres.

Is High Temporal Resolution Achievable for Paediatric Cardiac Acquisitions during Several Heart Beats? Illustration with Cardiac Phase Contrast Cine-MRI.

Background: During paediatric cardiac Cine-MRI, data acquired during cycles of different lengths must be combined. Most of the time, Feinstein's model is used to project multiple cardiac cycles of variable lengths into a mean cycle.

Objective: To assess the effect of Feinstein projection on temporal resolution of Cine-MRI.

Design of the DRAGET Study: a multicentre controlled diagnostic study to assess the detection of acute rejection in patients with heart transplant by means of T2 quantification with MRI in comparison to myocardial biopsies.

Introduction: Patients with heart transplant are screened for silent graft rejection by recurrent endomyocardial biopsies. MRI can detect the presence of oedema non-invasively by quantitatively measuring changes of the transverse relaxation time T2 in the myocardium. Several monocentric studies have shown that T2 quantification could help detect graft rejection in a less invasive way.

Nonrigid registration improves MRI T2 quantification in heart transplant patient follow-up.

Background: To evaluate the use of a nonrigid registration technique for detecting acute heart transplant rejection by MRI T2 quantification.

Methods: Myocardial T2 quantification was achieved in 279 consecutive examinations from 78 different patients. The protocol consisted of 10 successive black-blood fast spin echo sequences with varying echo times, and a postprocessing based on image registration and exponential fitting.

Diagnostic and prognostic value of MRI T2 quantification in heart transplant patients.

This study was designed retrospectively to assess the value of myocardial T2 to detect or predict ongoing acute heart rejection, in heart transplant patients, with a 1.5-T MRI magnet. One hundred and ninety-six myocardial T2 quantifications were performed on sixty consecutive heart transplant patients during routine follow-up.

Longitudinal myocardial peak velocities using high temporal resolution phase-contrast and simple averaging are comparable to tissue Doppler echocardiography.

Object: Phase contrast imaging is widely used to measure blood velocity. However tissue Doppler imaging (TDI) echocardiography is the reference for myocardial velocity assessment. This study aims at validating the ability of phase contrast (PC) sequences to correctly assess myocardial velocities and to compare these velocities to TDI.

Surface-length index: a novel index for rapid detection of right ventricles with abnormal ejection fraction using cardiac MRI.

Objective: To validate a new index, the surface-length index (SLI) based on area change in a short-axis view and length reduction in the horizontal long-axis view, which is used to quickly (<1 min) detect right ventricles with an abnormal ejection fraction (EF) during a cardiac MRI examination. SLI can be used to avoid a complete delineation of the endocardial contours of normal right ventricles.

Methods: Sixty patients (group A) were retrospectively included to calibrate the SLI formula by optimisation of the area under the ROC curves and SLI thresholds were chosen to obtain 100 % sensitivity.

Assessment of right ventricle volumes and function by cardiac MRI: quantification of the regional and global interobserver variability.

Reproducibility of the manual assessment of right ventricle volumes by short-axis cine-MRI remains low and is often attributed to the difficulty in separating the right atrium from the ventricle. This study was designed to evaluate the regional interobserver variability of the right ventricle volume assessment to identify segmentation zones with the highest interobserver variability. Short-axis views of 90 right ventricles (30 hypertrophic, 30 dilated, and 30 normal) were acquired with 2D steady-state free precession sequences at 1.

Echocardiographic right ventricle longitudinal contraction indices cannot predict ejection fraction in post-operative Fallot children.

Aims: To examine in a population of post-operative tetralogy of Fallot patients, the correlation between right ventricle (RV) ejection fractions (EF) computed from magnetic resonance imaging (MRI) and three echocardiographic indices of RV function: TAPSE, longitudinal strain and strain rate. Indeed, these patients present a pulmonary regurgitation which is responsible for progressive dilatation of the RV. An echocardiographic assessment of the RV function would be very useful in determining the timing of pulmonary revalvulation for Fallot patients.

Very early correction of anomalous left coronary artery from the pulmonary artery improves intensive care management.

Background: Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) can sometimes be diagnosed very early in newborns and thus be corrected surgically before any myocardial ischaemia occurs.

Aim: To evaluate the influence of this very early surgery on intensive care management and long-term outcome.

Methods: All children operated on for ALCAPA before the age of 1 year between 1995 and 2010 were considered.