Enhancement Cardiovascular Magnetic Resonance Imaging Research Articles

Quality control-driven deep ensemble for accountable automated segmentation of cardiac magnetic resonance LGE and VNE images.

Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging is the gold standard for non-invasive myocardial tissue characterisation. However, accurate segmentation of the left ventricular (LV) myocardium remains a challenge due to limited training data and lack of quality control. This study addresses these issues by leveraging generative adversarial networks (GAN)-generated virtual native enhancement (VNE) images to expand the training set and incorporating an automated quality control-driven (QCD) framework to improve segmentation reliability. A dataset comprising 4,716 LGE images (from 1,363 patients with hypertrophic cardiomyopathy and myocardial infarction) was used for development. To generate additional clinically validated data, LGE data were augmented with a GAN-based generator to produce VNE images. LV was contoured on these images manually by clinical observers. To create diverse candidate segmentations, the QCD framework involved multiple U-Nets, which were combined using statistical rank filters. The framework predicted the Dice Similarity Coefficient (DSC) for each candidate segmentation, with the highest predicted DSC indicating the most accurate and reliable result. The performance of the QCD ensemble framework was evaluated on both LGE and VNE test datasets (309 LGE/VNE images from 103 patients), assessing segmentation accuracy (DSC) and quality prediction (mean absolute error (MAE) and binary classification accuracy). The QCD framework effectively and rapidly segmented the LV myocardium (<1 s per image) on both LGE and VNE images, demonstrating robust performance on both test datasets with similar mean DSC (LGE: ; VNE: ; ). Incorporating GAN-generated VNE data into the training process consistently led to enhanced performance for both individual models and the overall framework. The quality control mechanism yielded a high performance (, ) emphasising the accuracy of the quality control-driven strategy in predicting segmentation quality in clinical settings. Overall, no statistical difference () was found when comparing the LGE and VNE test sets across all experiments. The QCD ensemble framework, leveraging GAN-generated VNE data and an automated quality control mechanism, significantly improved the accuracy and reliability of LGE segmentation, paving the way for enhanced and accountable diagnostic imaging in routine clinical use.

Lesion formation following pulsed field ablation for pulmonary vein and posterior wall isolation.

Pulsed field ablation (PFA) results in unique lesion formation, but there is lack of in-vivo validation in terms of scar formation following atrial fibrillation (AF) ablation. We aimed to access atrial lesion formation based on late gadolinium enhancement (LGE) cardiovascular magnetic resonance imaging (CMR) following PFA for pulmonary vein (PV) and posterior wall isolation (PWI). AF ablation was performed in 10 patients using a 31mm pentaspline PFA catheter. After pulmonary vein isolation (PVI; n=8 PFA-applications/ PV; n=4 in basket and n=4 in flower configuration), another eight applications in flower configuration were conducted for concomitant PWI. Patients underwent LGE CMR 3 months after ablation aiming for quantification of left atrial (LA) scar. Acute procedural success was achieved in all patients. Mean procedure duration was 62±7min. and mean LA dwell time of the PFA catheter was 13±2min. Mean post ablation total LA scar burden was 8.1±2.1% and mean scar width was 12.8±2.1mm. At the posterior LA, 22.6±2.2% of the anatomical segment resulted in chronic scar tissue, concentrated at the PW. Postablation CMR found no evidence for PV stenosis or collateral damage of adjacent structures. At 7 months of follow-up, 9/10 patients (90%) were free from arrhythmia recurrence. PFA for AF resulted in durable and transmural atrial scar tissue at the PVs and PW. LGE CMR found a very homogeneous and contiguous lesion pattern with no signs for collateral damage.

Left ventricular shape remodelling predicts major arrhythmic events in stable coronary artery disease

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): This work was supported by the National Institute for Health Research Biomedical Research Centre at Guy’s and St. Thomas’ Trust and King’s College, the Centre of Excellence in Medical Engineering funded by the Wellcome Trust and Engineering and Physical Sciences Research Council (EPSRC; WT088641/Z/09/Z). M.J.B. is supported by a Medical Research Council New Investigator Grant (MR/N011007/1) and British Heart Foundation (Project grant PG/18/74/34077). This work was supported by EPSRC 2018/19 DTP - EP/R513064/1 grant. This work was supported by a National Heart and Lung Institute Foundation grant awarded to Professor Sanjay Prasad and Dr Richard Jones. Background Arrhythmic risk stratification of patients with stable coronary artery disease (CAD) for defibrillator implantation remains imprecise. Current clinical guidelines center on a basic assessment of adverse cardiac remodelling, an approach with well documented limitations. More advanced analysis of intricate and regional LV remodelling in these patients may shed new insight for enhanced risk prediction of life-threatening arrhythmia in stable CAD. Objective We explored a novel computational 3D LV shape analysis strategy to accurately represent, and quantify, arrhythmogenic LV remodelling patterns in late gadolinium enhancement cardiovascular magnetic resonance images (LGE-CMR) in patients with stable CAD. We assess the utility of our patient-specific 3D LV arrhythmic shape (LVAS) score predicting major arrhythmic event; comparing to the current clinical benchmark of severely reduced LVEF and NYHA functional class. Methods Patients with stable CAD were prospectively recruited into a CMR registry and followed up for a composite endpoint of major arrhythmic events (MAE) consisting of sudden cardiac death (SCD), aborted SCD or haemodynamically unstable VT. Time-to-event data was also recorded. 2D LGE-CMR images were contoured and used as input to an advanced computational shape-analysis approach (Figure 1A). Reconstructed 3D LV shape models were analysed using Principle Component Analysis and Cox-Lasso to characterise the average arrhythmogenic LV shape, which was then used to quantitatively define a patient-specific LV arrhythmic shape (LVAS) score. Results Of 397 patients (mean [SD] LVEF% 45.4 ± 16.0) followed for a median (IQR) of 6 (3) years, 55 (14%) experienced a major arrhythmic event (MAE). The mean (SD) LVEF for patients who experienced MAE was lower than for those that did not (37.1% ± 13.2 vs 46.7% ± 16.0), yet there was no difference in NYHA class. LVAS mean (95% confidence interval [CI]) score was different between event and event-free patients: 2.98 (0.48-6.44) vs 19.83 (10.66-29), P&amp;lt;0.001. On univariate Cox regression analysis both LVAS score (hazard ratio [HR] 2.1, 95% CI 1.6-2.7, P&amp;lt;0.001) and LVEF&amp;lt;35% (HR 2.9, 95% CI 1.6-5.0, P&amp;lt;0.01) were associated with the primary endpoint. NYHA Class &amp;gt;I was not associated with the primary endpoint (HR 1.5, 95% CI 0.8-2.7, P=0.221). In multivariate Cox regression analysis, LVAS remained independently associated with the primary endpoint after adjusting for LVEF&amp;lt;35% and NYHA&amp;gt;Class I: LVAS score HR 2.1, 95% CI 1.5-3.0, P&amp;lt;0.001; LVEF&amp;lt;35% HR 1.0, 95% CI 0.5-2.2, P=0.923; NYHA&amp;gt;Class I HR 1.3, 95% CI 0.7-2.5, P=0.443 (Figure 1 B, C). The addition of the LVAS score increased the C-statistic from 0.6 to 0.75 between models. Conclusion A Left Ventricle Arrhythmic Shape score improved arrhythmic risk stratification compared to guideline-based clinical parameters, highlighting a potentially novel approach to identifying candidates for implantable cardioverter defibrillators in stable CAD.

Rare Case of an Adult With Double-Chambered Left Ventricle.

The rare case of an adult with a double-chambered left ventricle was revealed using multimodality imaging using echocardiography and cardiac magnetic resonance imaging in a 38-year-old asymptomatic male patient. The congenital malformation was dominated by a second, coarsely trabeculated muscular shelf dividing the left ventricle into 2 chambers without signs for left ventricular inflow or outflow tract obstruction. The partition wall did not show any signs for intramyocardial fibrosis in late gadolinium enhancement cardiovascular magnetic resonance imaging. Flow measurements excluded a relevant intracardial shunt across the additive perimembranous ventricular septal defect. There were no signs for global right and left ventricular dysfunction with left and right ventricular volumes and ejection fraction within normal limits. A conservative approach was recommended. In summary, we are able to present the case of an adult with a double-chambered left ventricle with a second muscular "septum" partially dividing the left ventricular cavity without causing a relevant impact on cardiac function or clinical signs for heart failure.

Dark-blood late gadolinium enhancement CMR improves detection of papillary muscle fibrosis in patients with mitral valve prolapse

PurposePapillary muscle fibrosis may act as an arrhythmogenic substrate in patients with mitral valve prolapse (MVP). Previous studies used conventional bright-blood late gadolinium enhancement cardiovascular magnetic resonance (LGE CMR) imaging to assess papillary muscle fibrosis, although this technique suffers from poor scar-to-blood contrast which may limit its sensitivity, in contrast to dark-blood LGE. This study sought to compare bright-blood and dark-blood LGE for the detection of papillary muscle fibrosis in patients with MVP. Method60 patients with known isolated MVP referred for CMR were prospectively recruited. A routine CMR protocol was used to obtain cine imaging, dark-blood LGE and bright-blood LGE in three long-axis views and a stack of short-axis views. Flow mapping of the proximal aorta was performed to calculate mitral regurgitant volume. Images were analysed for cardiac volumes, ejection fraction, mitral regurgitation severity, MVP characteristics (mitral annular disjunction, prolapse volume) and presence of LGE at the papillary muscles and myocardium. ResultsDark-blood LGE detected significantly more subjects with LGE at the papillary muscles than bright-blood LGE (35% vs 15%, p = 0.002). There was no difference between LGE techniques regarding myocardial (non-papillary muscle) fibrosis (present in 25% each). No statistical differences were observed between patients with or without LGE at the papillary muscles regarding demographics, clinical data (including ventricular arrhythmia) and MVP characteristics. Furthermore, no association was found between LGE at the papillary muscles and at the myocardium. ConclusionsCompared to bright-blood LGE, dark-blood LGE CMR improves the detection of LGE at the papillary muscles in patients with MVP.

Late Gadolinium Enhancement Cardiovascular Magnetic Resonance Assessment of Substrate for Ventricular Tachycardia With Hemodynamic Compromise.

Background: The majority of data regarding tissue substrate for post myocardial infarction (MI) VT has been collected during hemodynamically tolerated VT, which may be distinct from the substrate responsible for VT with hemodynamic compromise (VT-HC). This study aimed to characterize tissue at diastolic locations of VT-HC in a porcine model.Methods: Late Gadolinium Enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging was performed in eight pigs with healed antero-septal infarcts. Seven pigs underwent electrophysiology study with venous arterial-extra corporeal membrane oxygenation (VA-ECMO) support. Tissue thickness, scar and heterogeneous tissue (HT) transmurality were calculated at the location of the diastolic electrograms of mapped VT-HC.Results: Diastolic locations had median scar transmurality of 33.1% and a median HT transmurality 7.6%. Diastolic activation was found within areas of non-transmural scar in 80.1% of cases. Tissue activated during the diastolic component of VT circuits was thinner than healthy tissue (median thickness: 5.5 mm vs. 8.2 mm healthy tissue, p < 0.0001) and closer to HT (median distance diastolic tissue: 2.8 mm vs. 11.4 mm healthy tissue, p < 0.0001). Non-scarred regions with diastolic activation were closer to steep gradients in thickness than non-scarred locations with normal EGMs (diastolic locations distance = 1.19 mm vs. 9.67 mm for non-diastolic locations, p < 0.0001). Sites activated late in diastole were closest to steep gradients in tissue thickness.Conclusions: Non-transmural scar, mildly decreased tissue thickness, and steep gradients in tissue thickness represent the structural characteristics of the diastolic component of reentrant circuits in VT-HC in this porcine model and could form the basis for imaging criteria to define ablation targets in future trials.

Toward Replacing Late Gadolinium Enhancement With Artificial Intelligence Virtual Native Enhancement for Gadolinium-Free Cardiovascular Magnetic Resonance Tissue Characterization in Hypertrophic Cardiomyopathy.

Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging is the gold standard for noninvasive myocardial tissue characterization but requires intravenous contrast agent administration. It is highly desired to develop a contrast agent-free technology to replace LGE for faster and cheaper CMR scans. A CMR virtual native enhancement (VNE) imaging technology was developed using artificial intelligence. The deep learning model for generating VNE uses multiple streams of convolutional neural networks to exploit and enhance the existing signals in native T1 maps (pixel-wise maps of tissue T1 relaxation times) and cine imaging of cardiac structure and function, presenting them as LGE-equivalent images. The VNE generator was trained using generative adversarial networks. This technology was first developed on CMR datasets from the multicenter Hypertrophic Cardiomyopathy Registry, using hypertrophic cardiomyopathy as an exemplar. The datasets were randomized into 2 independent groups for deep learning training and testing. The test data of VNE and LGE were scored and contoured by experienced human operators to assess image quality, visuospatial agreement, and myocardial lesion burden quantification. Image quality was compared using a nonparametric Wilcoxon test. Intra- and interobserver agreement was analyzed using intraclass correlation coefficients (ICC). Lesion quantification by VNE and LGE were compared using linear regression and ICC. A total of 1348 hypertrophic cardiomyopathy patients provided 4093 triplets of matched T1 maps, cines, and LGE datasets. After randomization and data quality control, 2695 datasets were used for VNE method development and 345 were used for independent testing. VNE had significantly better image quality than LGE, as assessed by 4 operators (n=345 datasets; P<0.001 [Wilcoxon test]). VNE revealed lesions characteristic of hypertrophic cardiomyopathy in high visuospatial agreement with LGE. In 121 patients (n=326 datasets), VNE correlated with LGE in detecting and quantifying both hyperintensity myocardial lesions (r=0.77-0.79; ICC=0.77-0.87; P<0.001) and intermediate-intensity lesions (r=0.70-0.76; ICC=0.82-0.85; P<0.001). The native CMR images (cine plus T1 map) required for VNE can be acquired within 15 minutes and producing a VNE image takes less than 1 second. VNE is a new CMR technology that resembles conventional LGE but without the need for contrast administration. VNE achieved high agreement with LGE in the distribution and quantification of lesions, with significantly better image quality.

Right ventricular insertion site fibrosis in a dilated cardiomyopathy referral population: phenotypic associations and value for the prediction of heart failure admission or death

BackgroundDilated cardiomyopathy (DCM) is increasingly recognized as a heterogenous disease with distinct phenotypes on late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging. While mid-wall striae (MWS) fibrosis is a widely recognized phenotypic risk marker, other fibrosis patterns are prevalent but poorly defined. Right ventricular (RV) insertion (RVI) site fibrosis is commonly seen, but without objective criteria has been considered a non-specific finding. In this study we developed objective criteria for RVI fibrosis and studied its clinical relevance in a large cohort of patients with DCM.Methods We prospectively enrolled 645 DCM patients referred for LGE-CMR. All underwent standardized imaging protocols and baseline health evaluations. LGE images were blindly scored using objective criteria, inclusive of RVI site and MWS fibrosis. Associations between LGE patterns and CMR-based markers of adverse chamber remodeling were evaluated. Independent associations of LGE fibrosis patterns with the primary composite clinical outcome of heart failure admission or death were determined by multivariable analysis.ResultsThe mean age was 56 ± 14 (28% female) with a mean left ventricular (LV) ejection fraction (LVEF) of 37%. At a median of 1061 days, 129 patients (20%) experienced the primary outcome. Any abnormal LGE was present in 306 patients (47%), inclusive of 274 (42%) meeting criteria for RVI site fibrosis and 167 (26%) for MWS fibrosis. All with MWS fibrosis showed RVI site fibrosis. Solitary RVI site fibrosis was associated with higher bi-ventricular volumes [LV end-systolic volume index (78 ± 39 vs. 66 ± 33 ml/m2, p = 0.01), RV end-diastolic volume index (94 ± 28 vs. 84 ± 22 ml/m2 (p < 0.01), RV end-systolic volume index (56 ± 26 vs. 45 ± 17 ml/m2, p < 0.01)], lower bi-ventricular function [LVEF 35 ± 12 vs. 39 ± 10% (p < 0.01), RV ejection fraction (RVEF) 43 ± 12 vs. 48 ± 10% (p < 0.01)], and higher extracellular volume (ECV). Patient with solitary RVI site fibrosis experienced a non-significant 1.4-fold risk of the primary outcome, increasing to a significant 2.6-fold risk when accompanied by MWS fibrosis.ConclusionsRVI site fibrosis in the absence of MWS fibrosis is associated with bi-ventricular remodelling and intermediate risk of heart failure admission or death. Our study findings suggest RVI site fibrosis to be pre-requisite for the incremental development of MWS fibrosis, a more advanced phenotype associated with greater LV remodeling and risk of clinical events.

AL cardiac amyloidosis with widespread myocardial infiltration in the absence of hyperenhancement on conventional magnitude late gadolinium enhancement cardiovascular magnetic resonance imaging.

AL cardiac amyloidosis with widespread myocardial infiltration in the absence of hyperenhancement on conventional magnitude late gadolinium enhancement cardiovascular magnetic resonance imaging.

Prognostic value of myocardial scar by magnetic resonance imaging in patients undergoing coronary artery bypass graft

BackgroundPrevious studies demonstrated that scar tissue assessed by late gadolinium enhancement cardiovascular magnetic resonance imaging (LGE-CMR) is associated with recovery of cardiac function after coronary artery bypass graft (CABG) in patients with a history of myocardial infarction (MI). However, information on the association between myocardial scar at baseline and long-term survival after CABG in these patients is lacking. MethodsFrom April 2010 to May 2013, consecutive patients with multivessel coronary artery disease (CAD, > 70% stenosis in ≥2 vessels) and MI (> 3 months) who underwent LGE-CMR within 1 month prior to isolated CABG were enrolled. Left ventricular functional parameters and scar tissue were assessed by LGE-CMR before surgery. A standard 17-segment model was used for scar quantification. Predictors for cardiovascular events (CVEs) were analyzed. ResultsOf 148 patients who met the study inclusion/exclusion criteria, 140 cases had follow-up data and were included in final analysis. Of the latter, 27 (19.3%) patients suffered CVEs perioperatively or during mean 89.6 ± 12.0 months follow-up. In Cox proportional hazard regression model, the most significant predictor for CVEs after CABG was the number of scar segments on LGE-CMR (Hazard ratio 2.078, 95% Confidence Interval 1.133–3.814, P= 0.018). In Receiver-Operator-Characteristic (ROC) analysis, number of scar segments ≥6 predicted CVEs (sensitivity, 74.1%; specificity, 95.6%; area under the curve [AUC] = 0.934, P < 0.001). ConclusionsScar tissue identified by LGE-CMR appears to be an independent predictor of CVEs after CABG in patients with a history of MI, which might allow preoperative risk stratification.

Comparison of Segmentation Algorithms for Detecting Myocardial Infarction Using Late Gadolinium Enhancement Magnetic Resonance Imaging

Objective: The aim of this study was to validate the accuracy of a new automatic method for scar segmentation and compare its performance with that of two other frequently used segmentation algorithms. Methods: Twenty-six late gadolinium enhancement cardiovascular magnetic resonance images of diseased hearts were segmented by the full width at half maximum (FWHM) method, the n standard deviations (nSD) method, and our new automatic method. The results of the three methods were compared with the consensus ground truth obtained by manual segmentation of the ventricular boundaries. Results: Our automatic method yielded the highest Dice score and the lowest volume difference compared with the consensus ground truth segmentation. The nSD method produced large variations in the Dice score and the volume difference. The FWHM method yielded the lowest Dice score and the greatest volume difference compared with the automatic, 6SD, and 8SD methods, but resulted in less variation when different observers segmented the images. Conclusion: The automatic method introduced in this study is highly reproducible and objective. Because it requires no manual intervention, it may be useful for processing large datasets produced in clinical applications.

Left ventricular thrombus on cardiovascular magnetic resonance imaging in non-ischaemic cardiomyopathy.

Case reports have described left ventricular (LV) thrombus in patients with non-ischaemic cardiomyopathy (NICM). We aimed to systematically study the characteristics, predictors, and outcomes of LV thrombus in NICM. Forty-eight patients with LV thrombus detected on late gadolinium enhancement cardiovascular magnetic resonance imaging (LGE CMR) in NICM were compared with 124 patients with LV thrombus in ischaemic cardiomyopathy (ICM), and 144 matched patients with no LV thrombus in NICM. The performance of echocardiography for the detection of LV thrombus was compared between NICM and ICM. The 12-month incidence of embolism was compared between the three study groups. Independent predictors of LV thrombus in NICM were LV ejection fraction (LVEF) [hazard ratio (HR) 1.36 per 5% decrease; P = 0.002], LGE presence (HR 6.30; P < 0.001), and LGE extent (HR 1.33 per 5% increase; P = 0.001). Compared with patients with LV thrombus in ICM, those with LV thrombus in NICM had a 10-fold higher prevalence of thrombi in other cardiac chambers. The performance of echocardiography for the detection of LV thrombus was not different between NICM and ICM. The 12-month incidence of embolism associated with LV thrombus was not different between NICM and ICM (8.7% vs. 6.8%; P = 0.69) but both were higher compared with no LV thrombus in NICM (1.5%). Independent predictors of LV thrombus in NICM were lower LVEF, LGE presence, and greater LGE extent. The 12-month incidence of embolism associated with LV thrombus in NICM was not different compared with LV thrombus in ICM.

Predicting ventricular tachyarrhythmia in patients with systolic heart failure based on texture features of the gray zone from contrast-enhanced magnetic resonance imaging

BackgroundPrevious research showed that gray zone detected by late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR) imaging could help identify high-risk patients. In this study, we investigated whether LGE-CMR gray zone heterogeneity measured by image texture features could predict cardiovascular events in patients with heart failure (HF). MethodThis is a retrospective cohort study. Patients with systolic HF undergoing CMR imaging were enrolled. Cine and LGE images were analyzed to derive left ventricular (LV) function and scar characteristics. Entropy and uniformity of gray zones were derived by texture analysis. ResultsA total of 82 systolic HF patients were enrolled. After a median 1021 (25%–75% quartiles, 205–2066) days of follow-up, the entropy (0.60 ± 0.260 vs. 0.87 ± 0.28, p = 0.013) was significantly increased while the uniformity (0.68 ± 0.14 vs. 0.53±0.15, p = 0.016) was significantly decreased in patients with ventricular tachycardia or ventricular fibrillation (VT/VF). The percentage of core scar (21.9 ± 10.6 vs. 30.6 ± 10.4, p = 0.029) was higher in cardiac mortality group than survival group while the uniformity (0.55 ± 0.17 vs. 0.67 ± 0.14, p = 0.018) was lower in cardiac mortality group than survival group. A multivariate Cox regression model showed that higher percentage of gray zone area (HR = 8.805, 1.620−47.84, p = 0.045), higher entropy (>0.85) (HR = 1.391, 1.092−1.772, p = 0.024) and lower uniformity (≦0.54) (HR = 0.535, 0.340−0.842, p = 0.022) were associated with VT/VF attacks. Also, higher percentage of gray zone area (HR = 5.716, 1.379−23.68, p = 0.017), core scar zone (HR = 1.939, 1.056−3.561, p = 0.025), entropy (>0.85) (HR = 1.434, 1.076−1.911, p = 0.008) and lower uniformity (≦0.54) (HR = 0.513, 0.296−0.888, p = 0.009) were associated with cardiac mortality during follow-up. ConclusionsGray zone heterogeneity by texture analysis method could provide additional prognostic value to traditional LGE-CMR substrate analysis method.

Motion-corrected 3D whole-heart water-fat high-resolution late gadolinium enhancement cardiovascular magnetic resonance imaging

BackgroundConventional 2D inversion recovery (IR) and phase sensitive inversion recovery (PSIR) late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) have been widely incorporated into routine CMR for the assessment of myocardial viability. However, reliable suppression of fat signal, and increased isotropic spatial resolution and volumetric coverage within a clinically feasible scan time remain a challenge. In order to address these challenges, this work proposes a highly efficient respiratory motion-corrected 3D whole-heart water/fat LGE imaging framework.MethodsAn accelerated IR-prepared 3D dual-echo acquisition and motion-corrected reconstruction framework for whole-heart water/fat LGE imaging was developed. The acquisition sequence includes 2D image navigators (iNAV), which are used to track the respiratory motion of the heart and enable 100% scan efficiency. Non-rigid motion information estimated from the 2D iNAVs and from the data itself is integrated into a high-dimensional patch-based undersampled reconstruction technique (HD-PROST), to produce high-resolution water/fat 3D LGE images. A cohort of 20 patients with known or suspected cardiovascular disease was scanned with the proposed 3D water/fat LGE approach. 3D water LGE images were compared to conventional breath-held 2D LGE images (2-chamber, 4-chamber and stack of short-axis views) in terms of image quality (1: full diagnostic to 4: non-diagnostic) and presence of LGE findings.ResultsImage quality was considered diagnostic in 18/20 datasets for both 2D and 3D LGE magnitude images, with comparable image quality scores (2D: 2.05 ± 0.72, 3D: 1.88 ± 0.90, p-value = 0.62) and overall agreement in LGE findings. Acquisition time for isotropic high-resolution (1.3mm3) water/fat LGE images was 8.0 ± 1.4 min (3-fold acceleration, 60–88 slices covering the whole heart), while 2D LGE images were acquired in 5.6 ± 2.2 min (12–18 slices, including pauses between breath-holds) albeit with a lower spatial resolution (1.40–1.75 mm in-plane × 8 mm slice thickness).ConclusionA novel framework for motion-corrected whole-heart 3D water/fat LGE imaging has been introduced. The method was validated in patients with known or suspected cardiovascular disease, showing good agreement with conventional breath-held 2D LGE imaging, but offering higher spatial resolution, improved volumetric coverage and good image quality from a free-breathing acquisition with 100% scan efficiency and predictable scan time.

Long-Term Embolic Outcomes After Detection of Left Ventricular Thrombus by Late Gadolinium Enhancement Cardiovascular Magnetic Resonance Imaging: A Matched Cohort Study.

Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging is more sensitive than echocardiography for the detection of intracardiac thrombus because of its unique ability to identify thrombus based on tissue characteristics related to avascularity. The long-term prognostic significance of left ventricular (LV) thrombus detected by LGE CMR is unknown. We performed a matched cohort study of consecutive adult patients with LV thrombus detected by LGE CMR who were matched on the date of CMR, age, and LV ejection fraction to up to 3 patients without LV thrombus. We investigated the long-term incidence of a composite of embolic events: stroke, transient ischemic attack, or extracranial systemic arterial embolism. We also compared outcomes among patients with LV thrombus detected by LGE CMR stratified by whether the LV thrombus was also detected by echocardiography or not. Of 157 LV thrombus patients, 155 were matched to 400 non-LV thrombus patients. During a median follow-up of 3.3 years, the cumulative incidence of embolism was significantly higher in LV thrombus patients compared with the matched non-LV thrombus patients (P<0.001), with annualized rates of 3.7% and 0.8% for LV thrombus and matched non-LV thrombus patients, respectively. LV thrombus was the only independent predictor of the composite embolic end point (hazard ratio, 3.99 [95% CI, 1.54-10.35]; P=0.004). The cumulative incidence of embolism was not different in patients with LV thrombus that was also detected by echocardiography versus patients with LV thrombus not detected by echocardiography (P=0.25). Despite contemporary antithrombotic treatment, LV thrombus detected by LGE CMR is associated with a 4-fold higher long-term incidence of embolism compared with matched non-LV thrombus patients. LV thrombus detected by LGE CMR but not by echocardiography is associated with a similar risk of embolism as that detected by both LGE CMR and echocardiography.

Myocardial Fibrosis and Prognosis in Heart Transplant Recipients.

Myocardial fibrosis is a well-described histopathologic feature in heart transplant recipients. Whether myocardial fibrosis in heart transplant recipients is independently associated with clinical outcomes is unclear. We sought to determine whether myocardial fibrosis on late gadolinium enhancement cardiovascular magnetic resonance imaging in heart transplant recipients was independently associated with all-cause death or major adverse cardiac outcomes in the long-term. Using a cohort of consecutive heart transplant recipients that had cardiovascular magnetic resonance imaging, we determined the prevalence and the patterns of myocardial fibrosis and analyzed associations between myocardial fibrosis and a composite end point of all-cause death or major adverse cardiac events: retransplantation, nonfatal myocardial infarction, coronary revascularization, and heart failure hospitalization. One hundred and fifty-two heart transplant recipients (age, 54±15 years; 29% women; 5.0±5.4 years after heart transplantation) were included. Myocardial fibrosis was present in 18% (37% infarct pattern, 41% noninfarct pattern, and 22% both). Its prevalence was positively associated with cardiac allograft vasculopathy grade. With a median follow-up of 2.6 years, myocardial fibrosis was independently associated with all-cause death or major adverse cardiac events (hazard ratio, 2.88; 95% CI, 1.59-5.23; P<0.001) after adjustment for cardiac allograft vasculopathy, history of rejection, time since transplantation, left ventricular ejection fraction, and indexed right ventricular end-diastolic volume. Every 1% increase in myocardial fibrosis was independently associated with a 6% higher hazard for all-cause death or major adverse cardiac events (hazard ratio, 1.06; 95% CI, 1.03-1.09; P<0.001). The addition of myocardial fibrosis variables to models with cardiac allograft vasculopathy, history of rejection, time since transplantation, left ventricular ejection fraction, and indexed right ventricular end-diastolic volume resulted in significant improvements in model fit, suggesting incremental prognostic value. In heart transplant recipients, myocardial fibrosis is seen on late gadolinium enhancement cardiovascular magnetic resonance imaging in 18%. Both the presence and the extent of myocardial fibrosis are independently associated with the long-term risk of all-cause death or major adverse cardiac events.

2395LGE CMR predicts sudden death and VT in adults with repaired tetralogy of Fallot - a prospective study with 3500 patient follow up years

Abstract Background Adults with repaired tetralogy of Fallot (rtoF) are at risk of ventricular arrhythmia and sudden cardiac death (SCD). Cross-sectional data suggest association of late gadolinium enhancement (LGE) cardiovascular magnetic resonance imaging (CMR) with adverse clinical risk factors Purpose We sought to determine prognosis related to LGE CMR. Methods In this prospective cohort study the primary composite outcome comprised the first of cardiovascular death (SCD or heart failure-related), aborted SCD (successfully resuscitated cardiac arrest or appropriate AICD shock for ventricular fibrillation), and clinical sustained ventricular tachycardia (VT&gt;30 seconds duration). Results In 531 rtoF patients (median age 32; 23–42, 296 (56%) male, NYHA≥II 17%) followed up after LGE CMR for median 5 (1.7–8.9) years, there were 39 primary composite outcomes: 10 SCD, 11 heart failure related deaths (2 perioperative RV failure), 2 aborted SCD and 16 clinical sustained VT events. At study end, there were 28 ventricular arrhythmic events in 28 rtoF patients (10 SCD, 16 clinical sustained VT, 2 aborted VF) that were significantly predicted by RV LGE extent (HR 1.45 CI: 1.3–1.6; P&lt;0.001). Univariable predictors of the primary outcome were RV LGE score; HR: 1.44 (1.31–1.57; p&lt;0.001), (Figure) together with older age; HR: 1.05 (1.02–1.07; P&lt;0.001), late repair; HR: 1.04 (1.02–1.07; p&lt;0.001), lower RV ejection fraction; HR: 0.92 (0.89–0.95; p&lt;0.001), larger RVOT akinetic length; HR: 1.04 (1.02–1.06; p&lt;0.001) larger right atrial area; HR: 1.2 (1.12–1.29; p&lt;0.001); higher BNP levels; HR: 1.01 (1–1.02; p&lt;0.001), lower peak VO2; HR: 0.89 (0.83–0.96; p=0.001), prior atrial arrhythmia; HR: 5.3 (2.8–10.07; p&lt;0.001), and non-sustained VT; HR: 4.1 (2.1–7.7; p&lt;0.001). Inducible VT did not predict the primary outcome; HR: 2.1 (0.57–8; p=0.25) In multivariable analysis both RV LGE score and indexed right atrial area (RAAi) only, remained predictive of the primary outcome (HR 1.29 CI: 1.12–1.49; p&lt;0.001 and HR 1.1 CI: 1.02–1.12; p=0.01, respectively). Patients could accordingly be stratified such that supramedian RV LGE score (≥5) and RAAi ≥16cm2/m2 had 5-year event free survival 84% vs 94% for supramedian RV LGE score (≥5) and RAAi &lt;16cm2/m2 or 98% for inframedian RV LGE score with RAAI&lt;16cm2/m2. Figure. Conclusions For every unit increase in CMR defined RV fibrosis score there is a 44% increased risk of sudden cardiac death and VT. LGE CMR and maximal right atrial area should therefore be incorporated into risk stratification for sudden death in adults with rTOF. Acknowledgement/Funding British heart foundation

THE PATTERN OF MYOCARDIAL FIBROSIS DETECTED BY CARDIOVASCULAR MAGNETIC RESONANCE IMAGING PROVIDES PROGNOSTIC INFORMATION IN PATIENTS WITH IDIOPATHIC DILATED CARDIOMYOPATHY

Left ventricular mid-wall fibrosis (MWF), which is detected by mid-wall hyperenhancement on late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR) imaging, predicts mortality and morbidity in patients with idiopathic dilated cardiomyopathy (IDCM). However, in clinical practice,

Impact of Myocardial Viability Assessed by Delayed Enhancement Cardiovascular Magnetic Resonance on Clinical Outcomes in Real World Practice

Background: Delayed enhancement cardiovascular magnetic resonance imaging (DeCMRI) has become the preferred method for viability assessment. It is well established that viable dysfunctional myocardium has the potential for functional recovery after revascularization.

Myocardial Partition Coefficient of Gadolinium: A Pilot Study in Patients With Acute Myocarditis, Chronic Myocardial Infarction, and in Healthy Volunteers

BackgroundThe tissue-blood partition coefficient (PC) of gadolinium, derived from T1 measurements, reflects myocardial connective tissue fraction and tissue injury, increasing in proportion with edema or fibrosis. We determined the myocardial PC of gadolinium in patients with acute myocarditis, chronic myocardial infarction (MI), and healthy volunteers. We hypothesized that the characteristics of the injured myocardium in patients with MI and myocarditis may differ and that the PC will be higher in chronically injured myocardium (MI) compared with acutely injured myocardium (myocarditis). MethodsWe performed late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging and T1 mapping before and after administration of gadolinium (0.1 mmol/kg Gd-BOPTA) at 3 Tesla in 10 healthy volunteers (47.1 ± 12.4 years), 18 patients with chronic MI (62.5 ± 8.1 years), and 16 patients with acute myocarditis (42.5 ± 13.9 years). ResultsIn patients with chronic MI and focal scar by LGE, the whole left ventricular myocardial PC (0.45 ± 0.05) was higher compared with patients with MI without focal scar (0.39 ± 0.03, P = 0.02) but not significantly different from whole myocardial PC in volunteers (0.40 ± 0.05) or patients with myocarditis (0.41 ± 0.05). The PC in myocarditis scars was lower than in chronic MI scars (0.60 ± 0.12 vs 0.77 ± 0.16, P = 0.016). The relationships of PC and scar burden, expressed as % LGE, were similar and significant for the 2 groups (P = 0.042). ConclusionThe tissue-blood partition coefficient of Gd-BOPTA is elevated in areas of acute and chronic myocardial injury and may serve as a marker for disease activity and density of scars, which was found to be higher in chronic MI than in acute myocarditis.