Publications by authors named "Dudley Pennell"

Article Synopsis
  • Intravoxel incoherent motion (IVIM) imaging traditionally has low sensitivity in measuring heart perfusion, prompting the development of a more effective stimulated-echo (STEAM) method for better assessment of cardiac microstructure and perfusion.
  • The new STEAM-IVIM technique collects data at 20 different b-values and 6 diffusion directions, allowing thorough analysis of heart tissue in 20 healthy individuals.
  • The results indicate high-quality imaging with promising IVIM parameters and diffusion tensor metrics, suggesting that this method can detect abnormalities in heart microstructure and perfusion without needing contrast agents.
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Background: Echocardiography, cardiac magnetic resonance and cardiac fluorodeoxyglucose positron emission tomography (FDG-PET) imaging play key roles in the diagnosis and management of cardiac sarcoidosis (CS), but the relative value of each modality in predicting outcomes has yet to be determined. This study sought to determine the prognostic importance of multimodality imaging data over and above demographic characteristics and left ventricular ejection fraction (LVEF).

Methods: Consecutive patients newly diagnosed with CS were included.

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Background And Aims: Microstructural disturbances underlie dysfunctional contraction and adverse left ventricular (LV) remodelling after ST-elevation myocardial infarction (STEMI). Biphasic diffusion tensor cardiovascular magnetic resonance (DT-CMR) quantifies dynamic reorientation of sheetlets (E2A) from diastole to systole during myocardial thickening, and markers of tissue integrity [mean diffusivity (MD) and fractional anisotropy (FA)]. This study investigated whether microstructural alterations identified by biphasic DT-CMR: (i) enable contrast-free detection of acute myocardial infarction (MI); (ii) associate with severity of myocardial injury and contractile dysfunction; and (iii) predict adverse LV remodelling.

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Aims: In TRED-HF, 40% of patients with recovered dilated cardiomyopathy (DCM) relapsed in the short term after therapy withdrawal. This follow-up investigates the longer-term effects of therapy withdrawal.

Methods And Results: TRED-HF was a randomized trial investigating heart failure therapy withdrawal in patients with recovered DCM over 6 months.

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Background: Myocardial fibrosis (MF) forms part of the arrhythmic substrate for ventricular arrhythmias (VAs).

Objectives: This study sought to determine whether total myocardial fibrosis (TF) and gray zone fibrosis (GZF), assessed using cardiovascular magnetic resonance, are better than left ventricular ejection fraction (LVEF) in predicting ventricular arrhythmias in patients with nonischemic cardiomyopathy (NICM).

Methods: Patients with NICM in a derivation cohort (n = 866) and a validation cohort (n = 848) underwent quantification of TF and GZF.

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Aims: To assess whether left ventricular (LV) global longitudinal strain (GLS), derived from cardiovascular magnetic resonance (CMR), is associated with (i) progressive heart failure (HF), and (ii) sudden cardiac death (SCD) in patients with dilated cardiomyopathy with mildly reduced ejection fraction (DCMmrEF).

Methods And Results: We conducted a prospective observational cohort study of patients with DCM and LV ejection fraction (LVEF) ≥40% assessed by CMR, including feature-tracking to assess LV GLS and late gadolinium enhancement (LGE). Long-term adjudicated follow-up included (i) HF hospitalization, LV assist device implantation or HF death, and (ii) SCD or aborted SCD (aSCD).

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Background: Cardiovascular magnetic resonance (CMR) derived global function index (GFI) and myocardial contraction fraction (MCF) were identified as useful imaging markers to assess left ventricular (LV) cardiac performance and can provide prognostic information for several cardiac diseases. As pediatric reference values are lacking, the aim of this retrospective study was to establish these values.

Methods: 154 CMR examinations of healthy children and adolescents (4-18 years) were included.

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Background: There is conflicting evidence regarding the response to a fixed dose of regadenoson in patients with high body weight. The aim of this study was to evaluate the effectiveness of regadenoson in patients with varying body weights using novel quantitative cardiovascular magnetic resonance (CMR) perfusion parameters in addition to standard clinical markers.

Methods: Consecutive patients with typical angina and/or risk factors for coronary artery disease (N = 217) underwent regadenoson stress CMR perfusion imaging using a dual-sequence quantitative protocol with perfusion parameters generated from an artificial intelligence (AI)-based algorithm.

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Background: In-vivo diffusion tensor cardiovascular magnetic resonance (DT-CMR) is an emerging technique for microstructural tissue characterization in the myocardium. Most studies are performed at 3T, where higher signal-to-noise ratio (SNR) should benefit this signal-starved method. However, a few studies have suggested that DT-CMR is possible at 1.

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Aims: This study aimed to compare the association between measures of left atrial (LA) structure and function, derived from cardiovascular magnetic resonance (CMR), with cardiovascular death or non-fatal heart failure events in patients with non-ischaemic dilated cardiomyopathy (DCM).

Methods And Results: CMR studies of 580 prospectively recruited patients with DCM in sinus rhythm [median age 54 (interquartile range 44-64) years, 61% men, median left ventricular ejection fraction 42% (30-51%)] were analysed for measures of LA structure [LA maximum volume index (LAVImax) and LA minimum volume index (LAVImin)] and function (LA emptying fraction, LA reservoir strain, LA conduit strain (LACS), and LA booster strain]. Over a median follow-up of 7.

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Article Synopsis
  • In vivo cardiac diffusion tensor imaging (cDTI) is an MRI technique that assesses the microstructure of heart tissue, crucial for understanding cardiac function and creating new treatment options.
  • The study examines three deep learning-based reconstruction models for cDTI, comparing them on reconstruction quality, tensor parameter assessments, and computational costs.
  • Results showed the D5C5 model had the best reconstruction quality while the SwinMR model got higher perceptual rankings; however, all models struggled at higher acceleration factors, limiting their clinical readiness.
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MRI-based prognostic evaluation in patients with dilated cardiomyopathy (DCM) has historically used markers of late gadolinium enhancement (LGE) and feature tracking (FT)-derived left ventricular global longitudinal strain (LVGLS). Early data indicate that FT-derived left atrial strain (LAS) parameters, including reservoir, conduit, and booster, may also have prognostic roles in such patients. The purpose of our study was to evaluate the prognostic utility of LAS parameters, derived from MRI FT, in patients with ischemic or nonischemic DCM, including in comparison with the traditional parameters of LGE and LVGLS.

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Purpose: The study aims to assess the potential of referenceless methods of EPI ghost correction to accelerate the acquisition of in vivo diffusion tensor cardiovascular magnetic resonance (DT-CMR) data using both computational simulations and data from in vivo experiments.

Methods: Three referenceless EPI ghost correction methods were evaluated on mid-ventricular short axis DT-CMR spin echo and STEAM datasets from 20 healthy subjects at 3T. The reduced field of view excitation technique was used to automatically quantify the Nyquist ghosts, and DT-CMR images were fit to a linear ghost model for correction.

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Objective: The excellent blood and fat suppression of stimulated echo acquisition mode (STEAM) can be combined with saturation recovery single-shot acquisition (SASHA) in a novel STEAM-SASHA sequence for right ventricular (RV) native T1 mapping.

Materials And Methods: STEAM-SASHA splits magnetization preparation over two cardiac cycles, nulling blood signal and allowing fat signal to decay. Breath-hold T1 mapping was performed in a T1 phantom and twice in 10 volunteers using STEAM-SASHA and a modified Look-Locker sequence at peak systole at 3T.

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Purpose To compare left ventricular ejection fraction (LVEF) measured with echocardiography and cardiac MRI in individuals with cancer and suspected cardiotoxicity and assess the potential effect on downstream clinical decision-making. Materials and Methods In this prospective, single-center observational cohort study, participants underwent same-day two-dimensional (2D) echocardiography and cardiac MRI between 2011 and 2021. Participants with suboptimal image quality were excluded.

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Introduction: Quality assurance (QA) of measurements derived from MRI can require complicated test phantoms. This work introduces a new QA concept using gradient and transmit RF recordings by a limited field camera (FC) to govern the previous Virtual Phantom (ViP) method. The purpose is to describe the first technical implementation of combined FC+ViP, and illustrate its performance in examples, including quantitative first-pass myocardial perfusion.

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The electrocardiogram (ECG) signal is prone to distortions from gradient and radiofrequency interference and the magnetohydrodynamic effect during cardiovascular magnetic resonance imaging (CMR). Although Pilot Tone Cardiac (PTC) triggering has the potential to overcome these limitations, effectiveness across various CMR techniques has yet to be established. To evaluate the performance of PTC triggering in a comprehensive CMR exam.

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Background: Biological sex has a diverse impact on the cardiovascular system. Its influence on dilated cardiomyopathy (DCM) remains unresolved.

Objectives: This study aims to investigate sex-specific differences in DCM presentation, natural history, and prognostic factors.

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Background: Hypertrophic cardiomyopathy (HCM) is an important cause of sudden cardiac death associated with heterogeneous phenotypes, but there is no systematic framework for classifying morphology or assessing associated risks. Here, we quantitatively survey genotype-phenotype associations in HCM to derive a data-driven taxonomy of disease expression.

Methods: We enrolled 436 patients with HCM (median age, 60 years; 28.

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Background: GadaCAD2 was 1 of 2 international, multicenter, prospective, Phase 3 clinical trials that led to U.S. Food and Drug Administration approval of gadobutrol to assess myocardial perfusion and late gadolinium enhancement (LGE) in adults with known or suspected coronary artery disease (CAD).

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Aims: To characterize the phenotype, clinical outcomes and rate of disease progression in patients with early-stage non-ischaemic cardiomyopathy (early-NICM).

Methods And Results: We conducted a prospective observational cohort study of patients with early-NICM assessed by late gadolinium enhancement cardiovascular magnetic resonance (CMR). Cases were classified into the following subgroups: isolated left ventricular dilatation (early-NICM H-/D+), non-dilated left ventricular cardiomyopathy (early-NICM H+/D-), or early dilated cardiomyopathy (early-NICM H+/D+).

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