3D Cardiac Magnetic Resonance Research Articles

Basal inferoseptal segment is highly susceptible to deformation in the clinical spectrum of transthyretin-derived amyloid cardiomyopathy.

While the prevalence of transthyretin-derived amyloid cardiomyopathy (ATTR-CM) is on the rise, detailed understanding of its morphological and functional characteristics within the left ventricle (LV) across heart failure (HF) remains limited. Utilizing two-dimensional (2D) speckle-tracking echocardiography, we assessed longitudinal strain (LS) in 63 histology-confirmed ATTR-CM patients. Additionally, cardiac magnetic resonance (CMR) images measured native T1 and extracellular volume (ECV), compared with LS across 18 LV segments. Patients were categorized into three groups based on HF status: Group 1 (no HF symptoms), Group 2 (HF with preserved LV ejection fraction), and Group 3 (HF with reduced LV ejection fraction). LS analysis unveiled susceptibility to deformation in the basal inferoseptal segment, persisting even in asymptomatic cases. CMR demonstrated increasing native T1 deviation, particularly evident in segments distant from the inferoseptal region. Contrastingly, maximal ECV was consistently observed in the basal and mid-ventricular inferior-septum, even in asymptomatic individuals. Segmental LS decline correlated with ECV expansion but not with native T1 values. Our findings suggest that the inferoseptal segment is highly susceptible to amyloid infiltration, and 2D speckle-tracking echocardiography and CMR may serve as a valuable tool for its early detection.

Measurements of the Interventricular Septum and Mitral Leaflet Length in Hypertrophic Cardiomyopathy Patients Who Underwent Surgical Myectomy: A Prospective Comparative Multimodality Imaging Study

Transesophageal echocardiography (TEE) plays an important role for real-time procedural guidance during surgical myectomy (SM) for hypertrophic obstructive cardiomyopathy (HOCM). We aimed to compare a) IVS thickness using two (2D) and three-dimensional (3D) intraoperative TEE and pre-operative cardiac magnetic resonance (CMR) and b) mitral valve (MV) leaflet length using 2D, 3D TEE, automatic quantification of mitral valve (AMVQ) and pre-operative CMR. We prospectively studied 50 HOCM patients (age 59 ±12, 44% men) undergoing SM during 2018-2019. Maximal basal, mid, and distal anteroseptum (AS) and inferoseptum (IS) were measured by multiplanar 3D reconstruction on TEE and by short axis imaging on pre-operative CMR, and classified as mild (≤18mm), moderate (18-25mm) or severe (≥ 25 mm) groups, based on AS and IS thickness on CMR. MV leaflet lengths were evaluated by pre-operative CMR and intra-procedural 2D TEE, zoom 3D TEE and AMVQ (EchoPAC, General Electric, Wi). There was a moderate correlation between AS and IS thickness on 3D TEE and CMR (R2=0.46, p<0.01 and R2=0.41, p<0.01 respectively), with 3D TEE showing an average overestimation of 3.8 and 4.7 mm vs. CMR. 3D TEE over-estimated 14 (56%) patients with mild thickness as moderate, and 5 (22%) patients with moderate thickness as severe. Assuming 3D TEE as the gold standard, the closest correlation for anterior mitral leaflet length was with CMR (average overestimation by CMR of 0.5 mm [root mean square deviation or RMSE% 17]), intermediate correlation with 2D TEE (average deviation of 0.6 mm [RMSE%:21]) and no correlation with AMVQ (average deviation of 0.7mm [RMSE% 24]). In conclusion, 3D TEE overestimates IVS thickness vs. CMR in HOCM patients undergoing SM, with greater discrepancy in those with thinner IVS. There are significant differences in MV lengths measured using different imaging techniques.

European Association of Cardiovascular Imaging survey on the evaluation of mitral regurgitation.

To evaluate the diagnosis and imaging of patients with mitral regurgitation (MR) and the management in routine clinical practice across Europe, the European Association of Cardiovascular Imaging Scientific Initiatives Committee performed a survey across European centres. In particular, the routine use of echocardiography, advanced imaging modalities, heart valve clinics, and heart valve teams was explored. A total of 61 responders, mainly from tertiary centres or university hospitals, from 26 different countries responded to the survey, which consisted of 22 questions. For most questions related to echocardiography and advanced imaging, the answers were relatively homogeneous and demonstrated good adherence to current recommendations. In particular, the centres used a multi-parametric echocardiographic approach and selected the effective regurgitant orifice and vena contracta width as their preferred assessments. 2D measurements are still the most widely used parameters to assess left ventricular structure; however, the majority use 3D trans-oesophageal echocardiography (TOE) to evaluate valve morphology in severe MR. The majority of centres reported the onsite availability and clinical use of ergometric stress echocardiography, cardiac computed tomography (CCT), and cardiac magnetic resonance (CMR) imaging. Heart valve clinics and heart valve teams were also widely prevalent. Consistent with current guidelines, echocardiography (transthoracic echocardiography and TOE) remains the first-line and central imaging modality for the assessment of MR although the complementary use of 3D TOE, CCT, and CMR appears to be growing. Heart valve clinics and heart valve teams are now widely prevalent.

Abstract 14417: Regional 4D Cardiac Magnetic Resonance Strain Associates With Late Gadolinium Enhancement in Duchenne Muscular Dystrophy Associated Cardiomyopathy

Introduction: Cardiomyopathy (CM) is the leading cause of death in Duchenne muscular dystrophy (DMD). Onset and clinical progression are varied. Cardiac magnetic resonance (CMR) late gadolinium enhancement (LGE) can detect fibrofatty replacement prior to decreased left ventricular ejection fraction (LVEF) but requires administration of gadolinium contrast agents. Non-contrast methods to characterize CM onset and progression could decrease scan time and exposure to gadolinium. Using a novel 4D (3D+time) regional strain analysis method, we hypothesized that the regional magnitude of surface area strain (E a ) would be significantly decreased in DMD patients with LGE and that E a would correlate with decreased LVEF . Methods: Short-axis cine CMR images for 43 pediatric DMD patients (13.6 ± 4.2 years) were compiled into 4D sequences for regional strain analysis (Fig. 1A). For all 4D sequences, epi- and endocardial borders were segmented across one cardiac cycle for kinematic analysis using a custom-built MATLAB graphical user interface (MathWorks, Natick, MA). Regional E a was measured by determining the relative change in the localized 4D endocardial surface mesh compared to end-diastole. Unpaired t-test and Spearman’s rho were used to determine statistical significance and correlation. Results: DMD patients had a range of CM severity: 13 with reduced LVEF of &lt;55% (30% of total) and 28 with LGE (65% of total). Peak E a was significantly different between patients with and without LGE in the basal inferior ( p =0.022), basal inferolateral ( p &lt;0.001), basal anterolateral ( p =0.002), mid inferolateral ( p =0.004), mid anterolateral ( p =0.018), and apical anterior ( p &lt;0.032), regions (Fig.1B). Basal E a also correlated significantly with LVEF ( rho =-0.45, p&lt; 0.001; Fig. 1C). Conclusion: Regional E a from 4D CMR in DMD was reduced in patients with LGE compared to those without LGE particularly in the basolateral regions. Peak basal E a correlated with a reduction in LVEF. LVEF.

Time-Resolved 3D cardiopulmonary MRI reconstruction using spatial transformer network.

The accurate visualization and assessment of the complex cardiac and pulmonary structures in 3D is critical for the diagnosis and treatment of cardiovascular and respiratory disorders. Conventional 3D cardiac magnetic resonance imaging (MRI) techniques suffer from long acquisition times, motion artifacts, and limited spatiotemporal resolution. This study proposes a novel time-resolved 3D cardiopulmonary MRI reconstruction method based on spatial transformer networks (STNs) to reconstruct the 3D cardiopulmonary MRI acquired using 3D center-out radial ultra-short echo time (UTE) sequences. The proposed reconstruction method employed an STN-based deep learning framework, which used a combination of data-processing, grid generator, and sampler. The reconstructed 3D images were compared against the start-of-the-art time-resolved reconstruction method. The results showed that the proposed time-resolved 3D cardiopulmonary MRI reconstruction using STNs offers a robust and efficient approach to obtain high-quality images. This method effectively overcomes the limitations of conventional 3D cardiac MRI techniques and has the potential to improve the diagnosis and treatment planning of cardiopulmonary disorders.

Abstract 13519: 4D Cardiac Magnetic Resonance Strain Associates With Mortality in Duchenne Muscular Dystrophy Associated Cardiomyopathy

Introduction: Cardiomyopathy (CM) is the leading cause of death in Duchenne muscular dystrophy (DMD) but the pace of CM progression is variable. Identification of biomarkers that associate with mortality could allow clinicians to intensify cardiac therapy. Our objective was to determine whether novel 4D (3D+time) cardiac magnetic resonance (CMR) strain analysis predicts mortality. We hypothesized that the magnitude of regional surface strain (E a ) would be significantly decreased in DMD patients that progressed to mortality within 5 years of analysis. Methods: Short axis cine CMR images for DMD survival (n=40) and non-survival (n=9) groups were compiled into 4D sequences. For all 4D sequences, epi- and endocardial borders were segmented across one cardiac cycle for kinematic analysis using a custom-built MATLAB graphical user interface (MathWorks, Natick, MA). Regional E a was measured by determining the relative change in the localized 4D endocardial surface mesh compared to end diastole. Unpaired t-test was used to determine statistical significance. Results: DMD survival patients were younger (13 years [8-24]; median [range]) than non-survival patients (16[12-19]) and a smaller portion had LVEF&lt;55% (11 (28% of total) vs. 6 (67% of total). 63% (n=26) of the survival group had late gadolinium enhancement vs. 100% (n=9) in the non-survival group. Median time to mortality for the non-survival group was 27 months [8-58]. Peak E a was significantly worse in the non-survival group globally and in the basal, mid, and apical regions ( p &lt;0.001 for all; Fig1C). Qualitative E a maps show dramatic differences between groups (Fig1A,B). Conclusion: Regional E a from 4D CMR in DMD was reduced in patients that progressed to mortality within 5 years compared to those that survived. Figure 1: Example colorized surface strain (E a ) from A) survival and B) non-survival patients in both polar map (left) and 3D representations (right). C) Regional E a differences between groups. * p &lt;0.001.

Molecular and haemodynamic interplay in bicuspid aortic valve aortopathy: segmental differences across the aortic circumference

Abstract Background Bicuspid aortic valve (BAV) patients develop ascending aortic (AAo) dilation. The pathogenesis of BAV-aortopathy (genetic vs. hemodynamic) remains unclear. Purpose To identify regional changes around the AAo wall in BAV patients with aortopathy integrating clinical imaging and molecular data. Methods BAV patients with aortopathy (n=20) were recruited prospectively to surgically collect aortic tissue and perform four-dimensional cardiac magnetic resonance (CMR) scans. Molecular markers were measured analysing the tissue biopsies (n=15) and wall shear stress (WSS) across the AAo circumference was calculated from the 4D CMR data (n=11 patients, and n=7 additional healthy volunteers for comparison). Dilated (anterior/right) vs. non-dilated (posterior/left) circumferential segments were profiled for whole genomic microRNAs (Next Generation RNA-Sequencing, miRCURY LNA PCR), proteins content (Tandem Mass Spectrometry) and elastin fragmentation and degeneration (histomorphometric analysis). Picture 1 summarises the study approach (including a map of the AAo divided in the following segments: A=anterior, AR=anterior-right, PR=posterior-right, P=posterior, PL=posterior-left, AL=anterior-left). Results Integrated bioinformatic analyses of RNA-sequencing and proteomic datasets identified 5 microRNAs (miR-128-3p, miR-210-3p, miR-150-5p, miR-199b-5p, and miR-21-5p) differentially expressed across the AAo circumference. Among them, three miRNAs (miR-128-3p, miR-150-5p, and miR-199b-5p) were predicted to have an effect on eight common target genes, whose expression was dysregulated according to proteomic analyses and involved in vascular endothelial growth factor signalling, hippo signaling and arachidonic acid pathway. Decreased elastic fibre levels and elastic layer thickness were observed in the dilated segments in the histomorphometric analysis. Increased WSS and flow-velocity, helical streamlines and asymmetrical flow were observed at the anterior/right wall in asymmetrically and symmetrically dilated patients (the latter exhibiting higher WSS), compared to healthy volunteers. Conclusion This study has newly revealed concomitant expressional dysregulation of miRNAs, proteins, and elastic fibres on the anterior/right wall in dilated BAV patients, corresponding to regions of elevated WSS, contributing to advance the understanding of the interplay of genetic and hemodynamic factors underpinning BAV aortopathy. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): British Heart Foundation and Above &amp; Beyond

Left ventricular volume and ejection fraction measurements by fully automated 3D echocardiography left chamber quantification software versus CMR: A systematic review and meta-analysis

BackgroundAlthough transthoracic three-dimensional echocardiography (3DE) is now recommended by guidelines for left ventricular (LV) volumetric measurements, widespread implementation has been limited due to time constraints and required expertise. We hypothesized that fully automated 3DE left chamber quantification software might provide accurate measurements, and that its application could eliminate these obstacles. MethodsTo address this hypothesis, we conducted a systematic review and meta-analysis following a search for studies that compared LV volumes and ejection fraction (EF) using fully automated 3DE software (HeartModel or Dynamic HeartModel, Philips Healthcare, Andover, MA, USA) with cardiac magnetic resonance (CMR), from 2015 to 2021. A random effects model was used to determine biases, correlations, and 95 % confidence intervals (CI) of LV end-diastolic volume (EDV), end-systolic volume (ESV), and EF. Subgroup and meta-regression analyses were performed to determine effects of moderators on the outcome. ResultsOf 12 studies (616 subjects), mean differences and 95 % CIs in EDV, ESV, and EF between fully automated 3DE software and CMR were −19.6 mL (95 % CI; −27.6 to −11.5 mL), −11.4 mL (−16.7 to −6.2 mL), and 0.4 % (−1.1 to 2.0 %), respectively. Corresponding correlation values between the two methods were 0.91 (0.86–0.94), 0.89 (0.82–0.93), and 0.85 (0.81–0.88), respectively. Meta-regression analysis revealed that there were no effects of either publication year, type of software, or type of analysis on the outcome of LV volumetric and functional parameters except for publication year on LVESV correlation values. ConclusionsAlthough 3DE still underestimates LV volumes, the observed differences were no >20 mL. EF showed similar values to CMR. Excellent correlations between the two techniques make fully automated 3DE left chamber quantification software useful for routine clinical practice in adult population.

Accuracy of new transthoracic 3D echocardiographic automated algorithm for right ventricle quantification in children with congenital heart disease

Management of many congenital heart diseases (CHD) depends on right ventricle (RV) assessment for which cardiac magnetic resonance (CMR) remains the gold standard. The objective of this study was to assess feasibility and reproducibility of a new semi-automated algorithm to quantify RV (4D auto RVQ) from 3D transthoracic echocardiography (3D TTE) in a pediatric population, and to compare measurements with those obtained from CMR. In all, 90 infants were prospectively included (age 7.5 years, 3–18). Fifteen healthy infants and 75 patients with CHD (30 repaired TOF, 25 ASD, 8 dilated pulmonary valve stenosis, 7 tricuspid regurgitation, 3 APVR, and 2 repaired TAC). All patients underwent 2D and 3D TTE (Vivid E95, GE Healthcare). RV end-diastolic volume (RVEDV), RV end-systolic volume (RVESV), RV ejection volume (RVEV) and RV ejection fraction (RVEF) were analyzed by 4D auto RVQ and compared with measurements from 18 patients who underwent CMR exams for the follow up of their cardiopathy. 4D auto RVQ was feasible in 87 infants (96.7%). In 3 patients 4D auto RVQ was unable to detect RV contouring due to inadequate image quality. Manual contour adjustment was necessary in 81 cases (80%). Mean time of analysis including the time of manual adjustment was 62 seconds. RV was enlarged in 65 of 75 patients with CHD (mean 95 ml/m 2 , 62–165 ml/m 2 ). Good correlation for RVEDV, RVESV, RVEV and RVEF was found between 4D auto RVQ and CMR (r = 0.89–0.99, all P < 0.0001). 4D auto RVQ underestimated RVEDV/BSA of 8 ml/m 2 and RVEF by 6%, and overestimated RVESV/BSA of 9 ml/m 2 . Intraobserver and interobserver variability were low (4.7% and 8.9% respectively) ( Fig. 1 ). 4D auto RVQ is a promising tool for assessment of RV volume and function in children. Such simple and non-invasive exam could reduce the practice of CMR imaging during the follow up of children with CHD.

Diagnostic performance of 3D cardiac magnetic resonance perfusion in elderly patients for the detection of coronary artery disease as compared to fractional flow reserve

ObjectivesIn patients of advanced age, the feasibility of myocardial ischemia testing might be limited by age-related comorbidities and falling compliance abilities. Therefore, we aimed to test the accuracy of 3D cardiac magnetic resonance (CMR) stress perfusion in the elderly population as compared to reference standard fractional flow reserve (FFR).MethodsFifty-six patients at age 75 years or older (mean age 79 ± 4 years, 35 male) underwent 3D CMR perfusion imaging and invasive coronary angiography with FFR in 5 centers using the same study protocol. The diagnostic accuracy of CMR was compared to a control group of 360 patients aged below 75 years (mean age 61 ± 9 years, 262 male). The percentage of myocardial ischemic burden (MIB) relative to myocardial scar burden was further analyzed using semi-automated software.ResultsSensitivity, specificity, and positive and negative predictive values of 3D perfusion CMR deemed similar for both age groups in the detection of hemodynamically relevant (FFR < 0.8) stenosis (≥ 75 years: 86%, 83%, 92%, and 75%; < 75 years: 87%, 80%, 82%, and 85%; p > 0.05 all). While MIB was larger in the elderly patients (15% ± 17% vs. 9% ± 13%), the diagnostic accuracy of 3D CMR perfusion was high in both elderly and non-elderly populations to predict pathological FFR (AUC: 0.906 and 0.866).Conclusions3D CMR perfusion has excellent diagnostic accuracy for the detection of hemodynamically relevant coronary stenosis, independent of patient age.Key Points• The increasing prevalence of coronary artery disease in elderly populations is accompanied with a larger ischemic burden of the myocardium as compared to younger individuals.• 3D cardiac magnetic resonance perfusion imaging predicts pathological fractional flow reserve in elderly patients aged ≥ 75 years with high diagnostic accuracy.• Ischemia testing with 3D CMR perfusion imaging has similarly high accuracy in the elderly as in younger patients and it might be particularly useful when other non-invasive techniques are limited by aging-related comorbidities and falling compliance abilities.

Compressed sensing based dynamic MR image reconstruction by using 3D-total generalized variation and tensor decomposition: k-t TGV-TD

PurposeCompressed Sensing Magnetic Resonance Imaging (CS-MRI) is a promising technique to accelerate dynamic cardiac MR imaging (DCMRI). For DCMRI, the CS-MRI usually exploits image signal sparsity and low-rank property to reconstruct dynamic images from the undersampled k-space data. In this paper, a novel CS algorithm is investigated to improve dynamic cardiac MR image reconstruction quality under the condition of minimizing the k-space recording.MethodsThe sparse representation of 3D cardiac magnetic resonance data is implemented by synergistically integrating 3D total generalized variation (3D-TGV) algorithm and high order singular value decomposition (HOSVD) based Tensor Decomposition, termed k-t TGV-TD method. In the proposed method, the low rank structure of the 3D dynamic cardiac MR data is performed with the HOSVD method, and the localized image sparsity is achieved by the 3D-TGV method. Moreover, the Fast Composite Splitting Algorithm (FCSA) method, combining the variable splitting with operator splitting techniques, is employed to solve the low-rank and sparse problem. Two different cardiac MR datasets (cardiac perfusion and cine MR datasets) are used to evaluate the performance of the proposed method.ResultsCompared with the state-of-art methods, such as k-t SLR, 3D-TGV, HOSVD based tensor decomposition and low-rank plus sparse method, the proposed k-t TGV-TD method can offer improved reconstruction accuracy in terms of higher peak SNR (PSNR) and structural similarity index (SSIM). The proposed k-t TGV-TD method can achieve significantly better and stable reconstruction results than state-of-the-art methods in terms of both PSNR and SSIM, especially for cardiac perfusion MR dataset.ConclusionsThis work proved that the k-t TGV-TD method was an effective sparse representation way for DCMRI, which was capable of significantly improving the reconstruction accuracy with different acceleration factors.

MVSGAN: Spatial-Aware Multi-View CMR Fusion for Accurate 3D Left Ventricular Myocardium Segmentation.

The accurate 3D left ventricular (LV) myocardium segmentation in short-axis (SAX) view of cardiac magnetic resonance (CMR) is challenged by the sparse spatial structure of CMR. The strategy of multi-view CMR fusion can provide fine-grained spatial structure for accurate segmentation. However, the large information misalignment and lack of dense 3D CMR as fusion target in multi-view CMR fusion, and the different spatial resolution between the fusion result and the ground truth in segmentation limit the strategy. In this study, we propose a multi-view spatial-aware adversarial network (MVSGAN). It studies the perception of fine-grained cardiac structure for accurate segmentation by the spatialaware multi-view CMR fusion. It consists of three modules: (1) A residual adversarial fusion (RAF) module takes inter-slices deep correlation and anatomical prior to refine the spatial structures by residual supplement and adversarial optimization. (2) A structural perception-aggregation (SPA) module establishes the spatial correlation between the dense cardiac model and sparse label for accurate CMR LV myocardium segmentation. (3) A joint training strategy utilizes the dense SAX volume as explicit and implicit goals to jointly optimize the framework. The experiments are applied on a public dataset and a clinical dataset to evaluate the performance of MVSGAN. The average Dice and Jaccard score of LV myocardium segmentation obtained by MVSGAN are highest among seven existing state-of-the-art methods, which are up to 0.92 and 0.75. It is concluded that the spatial-aware multi-view CMR fusion can provide meaningful spatial correlation for accurate LV myocardium segmentation.

Longitudinal strain measurement by 3D modelling from cine CMR: feasibility and comparison to 2D speckle tracking echocardiography

Abstract Background Global longitudinal strain (GLS) has emerged as a sensitive index of left ventricular (LV) systolic function with greater prognostic value than LV ejection fraction (LVEF) in a variety of cardiac disorders. While GLS is routinely derived from 2D speckle tracking echocardiography (STE) and feature tracking in cardiac magnetic resonance (CMR) imaging, calculation of strain via 3D geometric modelling enables analyses of deformation that are independent of 2D image plane constraints. Purpose We sought to compare longitudinal strain measurements extracted from geometric 3D analysis of CMR against values obtained from conventional 2D-STE. Methods Consecutive 2D-echocardiography (2D-echo) and steady-state free precession multiplanar cine CMR scans were performed in 80 prospectively recruited participants (48 healthy controls with LVEF range 53–74%, 30 patients with non-ischaemic cardiac disease with LVEF range 25–77%, and 2 heart transplant recipients with LVEF 53% and 58%), &amp;lt;1 hour apart. Average endocardial peak GLS from 2D-STE was calculated offline using vendor-independent clinical software from apical triplane (2, 3 and 4-chamber) images for each of the standardised LV walls (anterior, anteroseptal, inferoseptal, inferior, inferolateral, anterolateral). Dynamic 3D geometric models of the LV were reconstructed from 3 long- and 6 short-axis CMR slices over one cardiac cycle. Corresponding longitudinal strain measurements were then evaluated by extracting analogous endocardial arc lengths (apex to base of each LV wall) from the 3D LV model. Finally, an average peak GLS was calculated as the mean of the peak longitudinal strains in each LV wall. Results GLS measured by 2D-STE ranged between −6.5% and −27.9% for the study population. A two-way mixed-effects intraclass correlation coefficient (ICC) for absolute agreement of 0.820 (95% CI: [0.720, 0.885]) demonstrated good correlation between average GLS obtained from 2D-STE and CMR. A Bland-Altman analysis revealed a minimal bias (&amp;lt;1%) and 95% limits of agreement (LOA) between −6.3% and 5.5% (Fig. 1), with no apparent proportional bias. Comparatively lower correlation and wider LOA between longitudinal strains from 2D-STE and CMR were observed for each LV wall (Table I). Conclusions Fully automated calculation of LV GLS can be obtained from geometric 3D CMR analysis. Average peak GLS from cine CMR exhibits good agreement with 2D-STE, despite showing only moderate agreement at each LV wall. The increased discrepancy in regional longitudinal strain may be attributed to subjective plane positioning in 2D-echo, which can be expected to improve with advances in 3D-STE. The calculation of GLS by 3D geometric modelling may enhance the diagnostic value of routine cine CMR examinations for LV systolic function assessment. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Health Research Council (HRC) of New Zealand and National Heart Foundation (NHF) of New Zealand Figure 1. Bland-Altman analysisTable I. Regional correlations

3D cardiac magnetic resonance stress-perfusion in elderly patients

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Swiss National Science Foundation Introduction Age related comorbidities and reduced compliance often limit ischaemia testing in elderly patients. Purpose To assessed the accuracy of 3D cardiac magnetic resonance (CMR) stress perfusion in the elderly population. Methods 56 patients aged ≥75 years underwent 3D CMR stress-perfusion and invasive coronary angiography with quantitative coronary angiography (QCA) and fractional flow reserve (FFR) as part of a multicenter study. The accuracy of 3D CMR stress-perfusion was compared to patients aged &amp;lt;75 years old (n = 360) using qualitative and quantitative imaging parameters. Results Sensitivity, specificity, positive and negative predictive values of qualitative 3D perfusion CMR were similar for both age groups in the detection of high-grade (≥50%) coronary stenosis on QCA and hemodynamically relevant (&amp;lt;0.8) stenosis on FFR, p &amp;gt; 0.05 all. Quantitative myocardial ischemia burden was larger in elderly patients (15% ± 17% vs. 9% ± 13%) with similarly high diagnostic accuracy of quantitative 3D CMR perfusion in both age groups to predict pathological FFR (AUC ≥75: 0.906; AUC &amp;lt;75: 0.866). Conclusions 3D CMR perfusion is well suited for myocardial ischaemia testing in the elderly patients with similarly high diagnostic accuracy as in younger individuals.

Clinical Validation of a 3-Dimensional Ultrafast Cardiac Magnetic Resonance Protocol Including Single Breath-Hold 3-Dimensional Sequences

ObjectivesThis study sought to clinically validate a novel 3-dimensional (3D) ultrafast cardiac magnetic resonance (CMR) protocol including cine (anatomy and function) and late gadolinium enhancement (LGE), each in a single breath-hold. BackgroundCMR is the reference tool for cardiac imaging but is time-consuming. MethodsA protocol comprising isotropic 3D cine (Enhanced sensitivity encoding [SENSE] by Static Outer volume Subtraction [ESSOS]) and isotropic 3D LGE sequences was compared with a standard cine+LGE protocol in a prospective study of 107 patients (age 58 ± 11 years; 24% female). Left ventricular (LV) mass, volumes, and LV and right ventricular (RV) ejection fraction (LVEF, RVEF) were assessed by 3D ESSOS and 2D cine CMR. LGE (% LV) was assessed using 3D and 2D sequences. ResultsThree-dimensional and LGE acquisitions lasted 24 and 22 s, respectively. Three-dimensional and LGE images were of good quality and allowed quantification in all cases. Mean LVEF by 3D and 2D CMR were 51 ± 12% and 52 ± 12%, respectively, with excellent intermethod agreement (intraclass correlation coefficient [ICC]: 0.96; 95% confidence interval [CI]: 0.94 to 0.97) and insignificant bias. Mean RVEF 3D and 2D CMR were 60.4 ± 5.4% and 59.7 ± 5.2%, respectively, with acceptable intermethod agreement (ICC: 0.73; 95% CI: 0.63 to 0.81) and insignificant bias. Both 2D and 3D LGE showed excellent agreement, and intraobserver and interobserver agreement were excellent for 3D LGE. ConclusionsESSOS single breath-hold 3D CMR allows accurate assessment of heart anatomy and function. Combining ESSOS with 3D LGE allows complete cardiac examination in <1 min of acquisition time. This protocol expands the indication for CMR, reduces costs, and increases patient comfort.

Simulation of Altered Blood Flow in Bicuspid Aortic Valve Disease: &amp;lt;i&amp;gt;A Proof of Concept Study&amp;lt;/i&amp;gt;

Background: Bicuspid aortic valve (BAV) is a common congenital heart disease which is associated with aortic dilatation. There is controversy in the literature regarding the various measures of the biomechanical properties of the aorta in these patients and their relationship to aortic dilatation. The present study aimed to assess both conventional 2D Cardiac Magnetic Resonance Imaging (CMRI) measurements of aortic biomechanics (compliance and distensibility) and a computational fluid dynamics (CFD) approach in patients with BAV and either normal or dilated ascending aorta. Methods: 2D CMRI was performed in 18 patients (6 controls, 6 BAV with dilated ascending aorta and 6 BAV with normal ascending aorta i.e. <36mm diameter) and ascending aortic compliance and distensibility was calculated. CFD was performed with <i>ANSYS Fluent software </i>using 2D CMRI derived parameters to simulate the hemodynamic relationships between blood and the aortic wall. Results: The groups were similar in terms of demographics (mean age 38±13 years, 56% male, pulse pressure 56±15mmHg). There was a numerically lower but not significant difference in aortic compliance between dilated BAV and the other groups. Aortic distensibility was no different between groups. Using CFD, at the mid-ascending aorta pressure was significantly higher in patients with dilated BAV (147.6 ± 24.1 mmHg) than non-dilated BAV (118.6 ± 16.2 mmHg) and controls (124.5 ± 14.4 mmHg), p=0.04. Conclusions: We demonstrate that is possible to estimate regional aortic pressure from 2D CMRI derived parameters using a CFD approach. These novel parameters may add value to surveillance strategies in aortic disease.

Trance-it to the Future

Trance-it to the Future

Reliable segmentation of 2D cardiac magnetic resonance perfusion image sequences using time as the 3rd dimension.

Cardiac magnetic resonance (CMR) first-pass perfusion is an established noninvasive diagnostic imaging modality for detecting myocardial ischemia. A CMR perfusion sequence provides a time series of 2D images for dynamic contrast enhancement of the heart. Accurate myocardial segmentation of the perfusion images is essential for quantitative analysis and it can facilitate automated pixel-wise myocardial perfusion quantification. In this study, we compared different deep learning methodologies for CMR perfusion image segmentation. We evaluated the performance of several image segmentation methods using convolutional neural networks, such as the U-Net in 2D and 3D (2D plus time) implementations, with and without additional motion correction image processing step. We also present a modified U-Net architecture with a novel type of temporal pooling layer which results in improved performance. The best DICE scores were 0.86 and 0.90 for LV myocardium and LV cavity, while the best Hausdorff distances were 2.3 and 2.1 pixels for LV myocardium and LV cavity using 5-fold cross-validation. The methods were corroborated in a second independent test set of 20 patients with similar performance (best DICE scores 0.84 for LV myocardium). Our results showed that the LV myocardial segmentation of CMR perfusion images is best performed using a combination of motion correction and 3D convolutional networks which significantly outperformed all tested 2D approaches. Reliable frame-by-frame segmentation will facilitate new and improved quantification methods for CMR perfusion imaging. • Reliable segmentation of the myocardium offers the potential to perform pixel level perfusion assessment. • A deep learning approach in combination with motion correction, 3D (2D + time) methods, and a deep temporal connection module produced reliable segmentation results.

Association between right ventricular strain and outcomes in patients with dilated cardiomyopathy

ObjectiveTo explore the association between three-dimensional (3D) cardiac magnetic resonance (CMR) feature tracking (FT) right ventricular peak global longitudinal strain (RVpGLS) and major adverse cardiovascular events (MACEs) in patients with...

Assessment of flow pattern of right ventricle outflow and pulmonary arteries in surgically corrected tetralogy of Fallot patients by four-dimensional cardiac magnetic resonance flow

BackgroundThe most common post-surgical complication of tetralogy of Fallot (TOF) is pulmonary regurgitation (PR) which can lead to right ventricle (RV) dysfunction/failure. Cardiac magnetic resonance (CMR) is the imaging modality of choice to follow-up a repaired TOF. However, the conventional two-dimensional phase-contrast (2D-PC) flow usually underestimates PR as well as the pulmonary peak systolic velocity (PSV). Recently, four-dimensional (4D) CMR flow is introduced for more accurate quantitative flow assessment. This work aimed to compare between 4D-CMR and 2D-PC flow across the main (MPA), right (RPA), and left (LPA) pulmonary arteries (PAs) in surgically corrected TOF patients.ResultsThis study was conducted on 20 repaired TOF patients (range 3–9 years, 50% males). All patients had CMR exam on 1.5T scanner. 4D-CMR and 2D-PC flows were obtained at the proximal segments of the MPA, RPA, and LPA. The stroke volume index (SVI), regurgitation fraction (RF), and PSV measured by 4D-CMR were compared to 2D-PC flow. The SVI across the PAs was nearly similar between both methods (P = 0.179 for MPA, 0.218 for RPA, and 0.091 for LPA). However, the RF was significantly higher by 4D-CMR in comparison to 2D-PC flow (P = 0.027 for MPA, 0.039 for RPA, and 0.046 for LPA). The PSV as well was significantly higher by 4D-CMR flow (P = 0.003 for MPA, < 0.001 for RPA, and 0.002 for LPA). The Bland-Altman plots showed a good agreement between 4D-CMR and 2D-PC flow for the SVI, RF, and PSV across the pulmonary arteries.ConclusionA good agreement existed between the two studied methods regarding pulmonary flow measurements. Because of its major advantage of performing a comprehensive flow assessment in a shorter time, 4D-CMR flow plays an important role in the assessment of patients with complex CHD especially in the pediatric group.