Standardized image interpretation and post-processing in cardiovascular magnetic resonance - 2020 update : Society for Cardiovascular Magnetic Resonance (SCMR): Board of Trustees Task Force on Standardized Post-Processing

Ferumoxytol-Enhanced 5D Multiphase Steady-State Imaging Using Rotating Cartesian K-Space With Low-Rank Reconstruction for Pediatric Congenital Heart Disease

BACKGROUND

The rotating Cartesian k-space multiphase steady-state imaging with contrast (ROCK-MUSIC) pulse sequence enables acquisition of whole-heart, cardiac phase-resolved images in pediatric congenital heart disease (CHD) without reliance on the ventilator gating signal. Multidimensional reconstruction with low rank tensor (LRT) has shown promise for resolving complex cardiorespiratory motion.

PURPOSE

To enhance ROCK-MUSIC by resolving cardiorespiratory phases using LRT reconstruction and to enable semi-automatic hyperparameter tuning by developing an image quality scoring model.

STUDY TYPE

Retrospective.

POPULATION

Thirty patients (45% female, age 2 days to 6.7 years) with CHD.

FIELD STRENGTH/SEQUENCE

3-T, four-dimensional (4D) spoiled gradient recalled echo sequence.

ASSESSMENT

Eigenvector-based iTerative Self-consistent Parallel Imaging Reconstruction (ESPIRiT) served as the reference comparison for LRT reconstruction. A 4-point Likert scale was used for cardiac and vascular image quality scoring based on cardiac chamber definition, lumen signal uniformity, vascular margin clarity, and motion artifact. Ejection fraction and ventricular volumes were assessed in 16 patients. Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and edge sharpness were computed.

STATISTICAL TESTS

Intraclass correlation coefficients, Wilcoxon signed-rank test, Bland-Altman. A P-value <0.05 was considered statistically significant.

RESULTS

Relative to ESPIRiT, LRT images received significantly higher cardiac (2.81 ± 0.57 vs. 3.19 ± 0.54) and vascular (2.81 ± 0.60 vs. 3.36 ± 0.53) image quality scores. Image quality scoring with semi-automated hyperparameter tuning showed strong correlations (R2 = 0.748) among image quality, SNR, and septal sharpness. Comparison of ejection fraction and volumetry derived from ESPIRiT, and LRT showed no significant systematic difference (P = 0.32).

DATA CONCLUSION

Integration of low-rank reconstruction with ROCK-MUSIC acquisition may be feasible, and semi-automatic hyperparameter tuning could be effective for generating cardiorespiratory resolved images.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 1.

Impact of training data composition on the generalizability of CNN aortic cross section segmentation in 4D Flow MRI

BACKGROUND

Time-resolved, three-dimensional phase-contrast magnetic resonance imaging (4D flow MRI) plays an important role in assessing cardiovascular diseases. However, the manual or semi-automatic segmentation of aortic vessel boundaries in 4D flow data introduces variability and limits reproducibility of aortic hemodynamics visualization and quantitative flow-related parameter computation. This paper explores the potential of deep learning to improve 4D flow MRI segmentation by developing models for automatic segmentation and analyzes the impact of the training data on the generalization of the model across different sites, scanner vendors, sequences, and pathologies.

METHODS

The study population consists of 260 4D flow MRI datasets, including subjects without known aortic pathology, healthy volunteers, and patients with bicuspid aortic valve (BAV) examined at different hospitals. The dataset was split to train segmentation models on subsets with different representations of characteristics such as pathology, gender, age, scanner model, vendor, and field strength. An enhanced 3D U-net convolutional neural network (CNN) architecture with residual units was trained for 2D+t aortic cross-sectional segmentation. The model performance was evaluated using Dice score, Hausdorff distance, and average symmetric surface distance on test data, datasets with characteristics not represented in the training set (model-specific), and an overall evaluation set. Standard diagnostic flow parameters were computed and compared with manual segmentation results using Bland-Altman analysis and interclass correlation.

RESULTS

The representation of technical factors such as scanner vendor and field strength in the training dataset had the strongest influence on the overall segmentation performance. Age had a greater impact than gender. Models solely trained on BAV patients' datasets performed well on datasets of healthy subjects but not vice versa.

CONCLUSION

This study highlights the importance of considering a heterogeneous dataset for the training of widely applicable automatic CNN segmentations in 4D flow MRI, with a particular focus on the inclusion of different pathologies and technical aspects of data acquisition.

Deep learning approaches for the detection of scar presence from cine cardiac magnetic resonance adding derived parametric images

This work proposes a convolutional neural network (CNN) that utilizes different combinations of parametric images computed from cine cardiac magnetic resonance (CMR) images, to classify each slice for possible myocardial scar tissue presence. The CNN performance comparison in respect to expert interpretation of CMR with late gadolinium enhancement (LGE) images, used as ground truth (GT), was conducted on 206 patients (158 scar, 48 control) from Centro Cardiologico Monzino (Milan, Italy) at both slice- and patient-levels. Left ventricle dynamic features were extracted in non-enhanced cine images using parametric images based on both Fourier and monogenic signal analyses. The CNN, fed with cine images and Fourier-based parametric images, achieved an area under the ROC curve of 0.86 (accuracy 0.79, F1 0.81, sensitivity 0.9, specificity 0.65, and negative (NPV) and positive (PPV) predictive values 0.83 and 0.77, respectively), for individual slice classification. Remarkably, it exhibited 1.0 prediction accuracy (F1 0.98, sensitivity 1.0, specificity 0.9, NPV 1.0, and PPV 0.97) in patient classification as a control or pathologic. The proposed approach represents a first step towards scar detection in contrast-free CMR images. Patient-level results suggest its preliminary potential as a screening tool to guide decisions regarding LGE-CMR prescription, particularly in cases where indication is uncertain.

Cardiovascular magnetic resonance reveals myocardial involvement in patients with active stage of inflammatory bowel disease

BACKGROUND

Active inflammatory bowel disease (A-IBD) but not remission (R-IBD) has been associated with an increased risk of cardiovascular death and hospitalization for heart failure.

OBJECTIVES

Using cardiovascular magnetic resonance (CMR), this study aims to assess adverse myocardial remodeling in patients with IBD in correlation with disease activity.

METHODS

Forty-four IBD patients without cardiovascular disease (24 female, median-age: 39.5 years, 26 A-IBD, 18 R-IBD) and 44 matched healthy volunteers (HV) were prospectively enrolled. The disease stage was determined by endoscopic and patient-reported criteria. Participants underwent CMR for cardiac phenotyping: cine imaging and strain analysis were performed to assess ventricular function. T1 mapping, extracellular volume and late-gadolinium enhanced images were obtained to assess focal and diffuse myocardial fibrosis. Simultaneous T1 and T2 elevation (T1 > 1049.3 ms, T2 > 54 ms) was considered to indicate a myocardial segment was inflamed.

RESULTS

16/44 (16.4%) IBD patients described dyspnea on exertion and 10/44 (22.7%) reported chest pain. A-IBD patients showed impaired ventricular function, indicated by reduced global circumferential and radial strain despite preserved left-ventricular ejection fraction. 16% of all IBD patients had focal fibrosis in a non-ischemic pattern. A-IDB patients had increased markers of diffuse left ventricular fibrosis (T1-values: A-IBD: 1022.0 ± 34.83 ms, R-IBD: 1010.10 ± 32.88 ms, HV: 990.61 ± 29.35 ms, p < .01). Significantly more participants with A-IDB (8/26, 30.8%) had at least one inflamed myocardial segment than patients in remission (0/18) and HV (1/44, 2.3%, p < .01). Markers of diffuse fibrosis correlated with disease activity.

CONCLUSION

This study, using CMR, provides evidence of myocardial involvement and patterns of adverse left ventricular remodeling in patients with IBD.

CLINICAL TRIAL REGISTRATION

ISRCTN30941346.

Pediatric reference values for myocardial contraction fraction and global function index of the left ventricle: A cardiovascular magnetic resonance study

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. LV end-diastolic, end-systolic and stroke volumes, ejection fraction (LVEF) and myocardial mass were measured using short axis stacks. Results were used to calculate LVGFI and LVMCF. Statistically, the Lambda-Mu-Sigma (LMS)-method was applied to create percentile curves and tables.

RESULTS

The mean age (standard deviation) of the subjects was 13.8 (2.8) years, 102 were male (66%). Mean LVGFI was 46.3 (6.0)% and mean LVMCF was 110.6 (19.9) %. Both, LVGFI and LVMCF decreased significantly with age (LVGFI: r = -0.30, p < 0.001; LVMCF: -0.30, p < 0.001). There was no statistical difference between girls and boys (p all >0.05). Strong correlations between LVGFI and LVMCF (r = 0.78, p < 0.001) as well as between LVGFI and LVEF (r = 0.80, p < 0.001) were documented whereas the correlation of LVMCF and LVEF was weaker (r = 0.32, p < 0.001). Univariable and multivariable regression analysis demonstrated that LVGFI was strongly associated with age whereas LVMCF was associated with weight. Percentile curves and tables were created accordingly.

CONCLUSION

We provide pediatric CMR reference values for the new cardiac functional markers LVGFI and LVMCF. These may improve the interpretation of clinical CMR studies and can be used for future research studies.

Incremental prognostic value of cardiovascular magnetic resonance imaging in patients with severe LV dysfunction undergoing coronary artery bypass grafting

BACKGROUND

Coronary artery disease (CAD) remains a significant global health issue, particularly when complicated by left ventricular ejection fraction (LVEF) < 35%. Although coronary artery bypass grafting (CABG) is recommended for such cases, the unclear prognosis necessitates further investigation.

METHOD

This retrospective study aimed to determine whether cardiovascular magnetic resonance (CMR) imaging provides additional prognostic value in guiding effective clinical management. The study included patients with CAD and LVEF < 35% who underwent CABG surgery after enhanced CMR between March 2016 and March 2023. CMR was performed using a 3.0T scanner with steady-state free precession and phase-sensitive inversion recovery sequences. Prognostic analysis of clinical and CMR data was conducted, with the endpoint defined as cardiovascular death, revascularization, hospitalization for heart failure, or stroke. Statistical analysis included Student's t-test, chi-squared test, univariate and multivariate Cox regression analysis, receiver operating characteristic analysis, Harrell C statistical analysis, integrated discrimination improvement (IDI), and net reclassification improvement (NRI) analysis.

RESULT

The study included 152 patients (mean age 58.6 ± 9.7 years; 138 men). During a mean follow-up of 2.0 years, 8 patients experienced cardiovascular death, while 1 case had revascularization, 13 had hospitalization for heart failure, and 11 had a stroke. Left atrial diameter index (LADi) (hazard ratio [HR], 1.08 [95% confidence interval (CI): 1.02-1.15]; P = 0.04) and late gadolinium enhancement (LGE) mass (HR, 1.03 [95% CI: 1.01-1.06]; P < 0.001) were associated with the endpoint, even after adjusting for multiple clinical variables. Adding LADi and LGE mass improved risk prediction for adverse events, as indicated by the C-index (0.738, p < 0.01), IDI (0.36), and NRI (0.13).

CONCLUSION

Left atrial diameter index (LADi) and scar burden are valuable prognostic indicators in patients with LVEF < 35% undergoing CABG. They offer enhanced risk stratification beyond traditional clinical factors, highlighting their importance in guiding clinical management.

Future of invasive and non-invasive hemodynamic assessment for coronary artery disease management

Coronary artery disease represents a global health challenge. Accurate diagnosis and evaluation of hemodynamic parameters are crucial for optimizing patient management and outcomes. Nowadays a wide range of both non-invasive and invasive methods are available to assess the hemodynamic impact of both epicardial coronary stenosis and vasomotor disorders. In fact, over the years, important developments have reshaped the nature of both invasive and non-invasive diagnostic techniques, and the future holds promises for further innovation and integration. Non-invasive techniques have progressively evolved and currently a broad spectrum of methods are available, from cardiac magnetic resonance imaging with pharmacological stress and coronary computed tomography (CT) to the newer application of FFR-CT and perfusion CT. Invasive methods, on the contrary, have developed to a full-physiology approach, able not only to identify functionally significant lesions but also to evaluate microcirculation and vasospastic disease. The aim of this review is to summarize the current state-of-the-art of invasive and non-invasive hemodynamic assessment for CAD management.

Right-Left Ventricular Interdependence in Repaired Tetralogy of Fallot Patients With Right Ventricular Heart Failure

BACKGROUND

Patients with repaired tetralogy of Fallot (rTOF) continue to face a heightened risk of deteriorating cardiac function, and quantitative techniques of cardiac MRI-derived cardiac structure and function provide an opportunity to explore the causes and mechanisms of cardiac deterioration.

PURPOSE

To explore right-left ventricular interdependence in rTOF patients before and after the onset of right ventricular (RV) heart failure.

STUDY TYPE

Retrospective.

POPULATION

One hundred eighteen rTOF patients (21.85 [16.74, 29.20] years, 58 females) and 34 controls (23.5 [21, 26.5] years, 17 females) that underwent cardiac MRI were analyzed, with rTOF patients being further subdivided into those with preserved RV function (N = 54) and those that experienced RV heart failure (N = 64).

FIELD STRENGTH/SEQUENCE

3.0 T/balanced steady-state free precession sequence.

ASSESSMENT

RV, left ventricular (LV), and septal strain; RV and LV volume.

STATISTICAL TESTS

Chi-squared tests or Fisher's exact test, One-way ANOVAs with Bonferroni's post hoc test, Pearson/Spearman correlation, and multivariate backward linear regression analysis. A two-tailed P < 0.05 was deemed as the significance threshold.

RESULTS

The MRI-derived RV, LV, and septal strain decreased sequentially in controls, patients with preserved RV function, and patients with RV heart failure, with a good intra-observer (0.909-0.964) and inter-observer (0.879-0.937) agreement. Correlations between LV and RV strain were found to change sequentially with RV function and were the closest in rTOF patients with RV heart failure (r = -0.270 to 0.506). Correlations between RV volume and septal strain was variable in controls (r = 0.483 to -0.604), patients with preserved RV function (r = -0.034 to -0.295), and patients with RV heart failure (r = -0.026 to 0.500). Multivariate analyses revealed that the RV longitudinal strain was independently correlated with LV strain in three directions in rTOF patients with RV heart failure (Radial -0.70 [-1.33, -0.06]; Circumferential 0.44 [0.17, 0.72]; Longitudinal 0.54 [0.26, 0.81]).

DATA CONCLUSION

In rTOF patients, the coupling between RV volume and septal strain was broken during RV function compensation, and the adverse effect of RV on LV deformation was highest in patients with RV heart failure.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 5.

Stronger positive correlation of the left ventricular mass index and extracellular volume fraction with diastolic function in diabetic patients without myocardial infarction

BACKGROUND

The structural and functional characteristics of the heart in patients with diabetes mellitus (DM) and without myocardial infarction (MI) are not fully understood.

METHODS

We retrospectively analysed the data of patients with left ventricular ejection fraction (LVEF) ≥ 40% who underwent contrast-enhanced cardiac magnetic resonance imaging (CMR), which was also used to exclude MI, at two hospitals. Volumetric data and extracellular volume fraction (ECVf) of the myocardium evaluated using CMR were compared between patients with and without DM, and their association with diastolic function was evaluated.

RESULTS

Among 322 analysed patients, 53 had DM. CMR revealed that the left ventricular mass index (LVMi) and ECVf were increased while LVEF was decreased in patients with DM after adjusting for patient characteristics (all P < 0.05). A stronger positive correlation was observed between LVMi and the early diastolic transmitral flow velocity to early diastolic mitral annular velocity ratio (E/e') in patients with DM than in those without DM (correlation coefficient [R] = 0.46, p = 0.001; R = 0.15, p = 0.021, respectively; p for interaction = 0.011). ECVf correlated with E/e' only in patients with DM (R = 0.61, p = 0.004).

CONCLUSIONS

Patients with DM have increased LVMi and ECVf. Importantly, there was a difference between patients with and without DM in the relationship between these structural changes and E/e', with a stronger relationship in patients with DM. Furthermore, DM is associated with mildly reduced LVEF even in the absence of MI.

DYNamic Assessment of Multi-Organ level dysfunction in patients recovering from COVID-19: DYNAMO COVID-19

We evaluated the impacts of COVID-19 on multi-organ and metabolic function in patients following severe hospitalised infection compared to controls. Patients (n = 21) without previous diabetes, cardiovascular or cerebrovascular disease were recruited 5-7 months post-discharge alongside controls (n = 10) with similar age, sex and body mass. Perceived fatigue was estimated (Fatigue Severity Scale) and the following were conducted: oral glucose tolerance (OGTT) alongside whole-body fuel oxidation, validated magnetic resonance imaging and spectroscopy during resting and supine controlled exercise, dual-energy X-ray absorptiometry, short physical performance battery (SPPB), intra-muscular electromyography, quadriceps strength and fatigability, and daily step-count. There was a greater insulin response (incremental area under the curve, median (inter-quartile range)) during the OGTT in patients [18,289 (12,497-27,448) mIU/min/L] versus controls [8655 (7948-11,040) mIU/min/L], P < 0.001. Blood glucose response and fasting and post-prandial fuel oxidation rates were not different. This greater insulin resistance was not explained by differences in systemic inflammation or whole-body/regional adiposity, but step-count (P = 0.07) and SPPB scores (P = 0.004) were lower in patients. Liver volume was 28% greater in patients than controls, and fat fraction adjusted liver T1, a measure of inflammation, was raised in patients. Patients displayed greater perceived fatigue scores, though leg muscle volume, strength, force-loss, motor unit properties and post-exercise muscle phosphocreatine resynthesis were comparable. Further, cardiac and cerebral architecture and function (at rest and on exercise) were not different. In this cross-sectional study, individuals without known previous morbidity who survived severe COVID-19 exhibited greater insulin resistance, pointing to a need for physical function intervention in recovery.

Assessment of Tricuspid Regurgitation by Cardiac Magnetic Resonance Imaging: Current Role and Future Applications

Tricuspid regurgitation (TR) is a prevalent valvular disease with a significant mortality rate. The evaluation of TR severity and associated right heart remodeling and dysfunction is crucial to determine the optimal therapeutic strategy and to improve prognosis. While echocardiography remains the first-line imaging technique to evaluate TR, it has many limitations, both operator- and patient-related. Cardiovascular magnetic resonance imaging (CMR) has emerged as an innovative and comprehensive non-invasive cardiac imaging technique with additional value beyond routine echocardiographic assessment. Besides its established role as the gold standard for the evaluation of cardiac volumes, CMR can add important insights with regard to valvular anatomy and function. Accurate quantification of TR severity, including calculation of regurgitant volume and fraction, can be performed using either the well-known indirect volumetric method or novel 4D flow imaging. In addition, CMR can be used to assess the impact on the right heart, including right heart remodeling, function and tissue characterization. Several CMR-derived parameters have been associated with outcome, highlighting the importance of multi-modality imaging in patients with TR. The aim of this review is to provide an overview of the current role of CMR in the assessment and management of patients with TR and its future applications.

Late Gadolinium Enhancement in Early Repolarization Syndrome

BACKGROUND

In patients with Brugada syndrome, myocardial fibrosis can be identified through epicardial biopsy or cardiac magnetic resonance imaging (CMR) with late gadolinium enhancement (LGE). However, the myocardial alterations in patients with early repolarization syndrome (ERS) remain poorly elucidated.

OBJECTIVE

To investigate the presence of myocardial fibrosis in patients with ERS using LGE in CMR.

METHODS

We retrospectively evaluated 20 ERS patients, all of whom exhibited J waves in the contiguous two leads. The location of J waves was classified as in the septum (V1-V2), anterior (V3-V4), lateral (I, aVL, V5-V6), inferior (II, III, aVF), or posterior (V7-V9) regions. To compare the distribution of LGE in CMR with J waves, sections of short-axis view of left ventricle (LV) were categorized as located in either the septum, anterior, lateral, inferior, and posterior regions.

RESULTS

Overall, 85% of ERS patients displayed LGE, which was more prevalent in the septum and posterior regions, followed by the inferior and lateral regions. The presences or absence of J waves and LGE coincided in 61% of LV areas, while discordance between the distributions of J waves and LGE was observed in 38%. LGE was most frequent in the septum (75%), where its reflection in J waves may be less robust. The appearance of LGE was not associated with symptoms, electrical storm, or VF occurrence during follow-up.

CONCLUSIONS

LGE is common among patients with ERS, and the distribution of J waves and LGE coincides in approximately sixty percent of LV areas.

Cardiovascular magnetic resonance parametric mapping in the risk stratification of patients affected by chronic myocarditis

OBJECTIVES

Chronic myocardial inflammation is the substrate for arrhythmias and dilated cardiomyopathy onset, causing morbidity and mortality. Cardiovascular magnetic resonance (CMR) is the noninvasive gold standard for myocardial inflammation detection, due to the high sensitivity of the parametric mapping techniques. However, the potential prognostic capabilities of CMR mapping have not been studied in the setting of chronic myocarditis.

METHODS

This is a retrospective study on consecutive patients undergoing CMR with suspicion of chronic myocarditis from September 2017 to November 2021. CMR was acquired according to 2018 Lake Louise Criteria recommendations. The outcome (chronic heart failure, recurrent chronic myocarditic chest pain, ICD/PM implantation, arrhythmias [Lown class ≥ 2]) was collected at follow-up. The extent and degree of native T1, T2, and extracellular volume fraction alterations were used to create multivariate binary logistic regression models for outcome prediction, with or without left ventricle ejection fraction; their AUCs were compared with DeLong test. Differences between other parameters were assessed using Chi-square test, Fisher's exact test, or Mann-Whitney U-test.

RESULTS

The population included 88 patients (age 43 [32-52] yo), mostly male (53/88, 60%). After a median follow-up of 21 (17-34) months, 31/88 (35%) patients experienced the outcome. The model based on the extension of mapping alterations and LV dysfunction reached a good predictability (AUC 0.71). The model based on the intensity of mapping alterations and LV dysfunction had a very good performance (AUC 0.80).

CONCLUSION

The quantitative analysis of CMR mapping parameters indicative of myocardial damage severity may improve risk stratification in patients with chronic myocarditis.

CLINICAL RELEVANCE STATEMENT

The intensity of myocardial damage, assessed as the degree of native T1, T2, and ECV alteration, together with left ventricle dysfunction, improved patient risk stratification. Further prospective studies will be necessary for validation before clinical application.

KEY POINTS

Risk stratification of patients affected by chronic myocarditis is an unmet clinical need. Cardiovascular MRI (CMR) can role in risk stratification thanks to its multiparametric capabilities of tissue characterization. A model based on CMR parametric mapping and left ventricle ejection fraction can predict arrhythmia, heart failure, and recurrent symptoms.

Clinical utility of a rapid two-dimensional balanced steady-state free precession sequence with deep learning reconstruction

BACKGROUND

Cardiovascular magnetic resonance (CMR) cine imaging is still limited by long acquisition times. This study evaluated the clinical utility of an accelerated two-dimensional (2D) cine sequence with deep learning reconstruction (Sonic DL) to decrease acquisition time without compromising quantitative volumetry or image quality.

METHODS

A sub-study using 16 participants was performed using Sonic DL at two different acceleration factors (8× and 12×). Quantitative left-ventricular volumetry, function, and mass measurements were compared between the two acceleration factors against a standard cine method. Following this sub-study, 108 participants were prospectively recruited and imaged using a standard cine method and the Sonic DL method with the acceleration factor that more closely matched the reference method. Two experienced clinical readers rated images based on their diagnostic utility and performed all image contouring. Quantitative contrast difference and endocardial border sharpness were also assessed. Left- and right-ventricular volumetry, left-ventricular mass, and myocardial strain measurements were compared between cine methods using Bland-Altman plots, Pearson's correlation, and paired t-tests. Comparative analysis of image quality was measured using Wilcoxon-signed-rank tests and visualized using bar graphs.

RESULTS

Sonic DL at an acceleration factor of 8 more closely matched the reference cine method. There were no significant differences found across left ventricular volumetry, function, or mass measurements. In contrast, an acceleration factor of 12 resulted in a 6% (5.51/90.16) reduction of measured ejection fraction when compared to the standard cine method and a 4% (4.32/88.98) reduction of measured ejection fraction when compared to Sonic DL at an acceleration factor of 8. Thus, Sonic DL at an acceleration factor of 8 was chosen for downstream analysis. In the larger cohort, this accelerated cine sequence was successfully performed in all participants and significantly reduced the acquisition time of cine images compared to the standard 2D method (reduction of 37% (5.98/16) p < 0.0001). Diagnostic image quality ratings and quantitative image quality evaluations were statistically not different between the two methods (p > 0.05). Left- and right-ventricular volumetry and circumferential and radial strain were also similar between methods (p > 0.05) but left-ventricular mass and longitudinal strain were over-estimated using the proposed accelerated cine method (mass over-estimated by 3.36 g/m2, p < 0.0001; longitudinal strain over-estimated by 1.97%, p = 0.001).

CONCLUSION

This study found that an accelerated 2D cine method with DL reconstruction at an acceleration factor of 8 can reduce CMR cine acquisition time by 37% (5.98/16) without significantly affecting volumetry or image quality. Given the increase of scan time efficiency, this undersampled acquisition method using deep learning reconstruction should be considered for routine clinical CMR.

Remote myocardial fibrosis predicts adverse outcome in patients with myocardial infarction on clinical cardiac magnetic resonance imaging

BACKGROUND

Heart failure (HF) most commonly occurs in patients who have had a myocardial infarction (MI), but factors other than MI size may be deterministic. Fibrosis of myocardium remote from the MI is associated with adverse remodelling. We aimed to i) Investigate the association between remote myocardial fibrosis, measured using cardiovascular magnetic resonance (CMR) extracellular volume (ECV), and HF and death following MI, ii) Identify predictors of remote myocardial fibrosis in patients with evidence of MI, and determine the relationship with infarct size.

METHODS

Multicentre prospective cohort study of 1,199 consecutive patients undergoing CMR with evidence of MI on late gadolinium enhancement. Median follow-up 1,133 (895-1,442) days. Cox proportional hazards modelling was used to identify factors predictive of the primary outcome, a composite of first hospitalisation for HF (HHF) or all-cause mortality, post-CMR. Linear regression modelling was used to identify determinants of remote ECV.

RESULTS

Remote myocardial fibrosis was a strong predictor of primary outcome (χ2: 15.6, HR: 1.07 per 1% increase in ECV, 95% CI: 1.04-1.11, p<0.001), and was separately predictive of both HHF and death. The strongest predictors of remote ECV were diabetes, sex, natriuretic peptides, and body mass index, but, despite extensive phenotyping, the adjusted model R2 was only 0.283. The relationship between infarct size and remote fibrosis was very weak.

CONCLUSIONS

Myocardial fibrosis, measured using CMR ECV, is a strong predictor of HHF and death in patients with evidence of MI. The mechanisms underlying remote myocardial fibrosis formation post-MI remain poorly understood, but factors other than infarct size appear to be important.

Interventricular septum involvement is related to right ventricular dysfunction in anterior STEMI patients without right ventricular infarction: a cardiovascular magnetic resonance study

The value of cardiovascular magnetic resonance (CMR) in assessing and predicting acute right ventricular (RV) dysfunction in patients with anterior ST-segment elevation myocardial infarction (STEMI) remains ascertained. Eighty eight patients with anterior STEMI were prospectively recruited and underwent CMR examinations within one week following the coronary intervention. Patients with RV ejection fraction (RVEF) less than 2 standard deviations below the average at the center (RVEF ≤ 45.0%) were defined as having RV dysfunction. The size of infarction, segmental wall motion, and T1 and T2 mapping values of global myocardium and the interventricular septum (IVS) were measured. Predictive performance was calculated using receiver-operating characteristic curve analysis and logistic regression test. Twenty two patients presented with RV dysfunction. The RV dysfunction group had a larger IVS infarct extent (54.28 ± 10.35 vs 33.95 ± 15.09%, P < 0.001) and lower left ventricle stroke volume index (33.93 ± 7.96 vs 42.46 ± 8.14 ml/m2, P < 0.001) compared to the non-RV dysfunction group. IVS infarct extent at 48.8% best predicted the presence of RV dysfunction with an area under the curve of 0.864. Left ventricular stroke volume index (LVSVI) and IVS infarct extent were selected by stepwise multivariable logistic regression analysis. Lower LVSVI (odds ratio [OR] 0.90; 95% confidence interval [CI], 0.79 to 0.99; P = 0.044) and higher IVS infarct extent (OR 1.16; 95% CI 1.05 to 1.33; P = 0.01) were found to be independent predictors for RV dysfunction. In patients with anterior STEMI, those with larger IVS infarct extent and worse LV function are more likely to be associated with RV dysfunction.

Diagnostic values of inferior Q-waves for myocardial scar identification detected by 3.0 T cardiac MRI

While Q-waves in inferior leads, particularly lead III, can be regarded as a minor abnormality, it can also indicate the presence of myocardial scar. This study assessed the diagnostic value of pathologic inferior Q-waves (lead II, III, aVF) for detecting ischemic scars using a high-resolution 3.0 T cardiac magnetic resonance (CMR). We retrospectively analyzed 1692 patients with suspected or known coronary artery disease who underwent stress CMR perfusion or viability assessment. Pathologic Q-waves were defined as duration of ≥ 30 ms and depth of ≥ 1 mm or QS-complex. Eleven models were created to evaluate the presence of Q-waves in different combinations of inferior leads. Of the 1692 patients, 436 (25.8%) had pathologic Q-waves. Models with Q-waves in leads II + aVF (model 7) and II + III + aVF (model 9) showed high specificity (100% and 99.6%), positive predictive value (PPV) (80.0% and 86.7%), and negative predictive value (NPV) (82.6% and 84.3%) but low sensitivity (1.3% and 13.1%). Other models also maintained high specificity and NPV but poor sensitivity and PPV. Notably, 21% of patients with an isolated pathologic Q-wave in lead III (model 4) exhibited scars. These findings highlight the need for careful clinical assessment when pathologic Q-waves are present.

Serum Concentrations of Matrix Metalloproteinase-1 and Procollagen Type I Carboxy Terminal Propeptide Discriminate Infarct-Like Myocarditis and Non-ST-Segment-Elevation Myocardial Infarction

BACKGROUND

Biomarkers simplifying the diagnostic workup by discriminating between non-ST-segment-elevation myocardial infarction (NSTEMI) and infarct-like myocarditis are an unmet clinical need.

METHODS AND RESULTS

A total of 105 subjects were categorized into groups as follows: ST-segment-elevation myocardial infarction (n=36), NSTEMI (n=22), infarct-like myocarditis (n=19), cardiomyopathy-like myocarditis (n=18), and healthy control (n=10). All subjects underwent cardiac magnetic resonance imaging, and serum concentrations of matrix metalloproteinase-1 (MMP-1) and procollagen type I carboxy terminal propeptide (PICP) were measured. Biomarker concentrations in subjects presenting with acute coronary syndrome and non-ST-segment-elevation, for example NSTEMI or infarct-like myocarditis, categorized as the non-ST-segment-elevation acute coronary syndrome-like cohort, were of particular interest for this study. Compared with healthy controls, subjects with myocarditis had higher serum concentrations of MMP-1 and PICP, while no difference was observed in individuals with myocardial infarction. In the non-ST-segment-elevation acute coronary syndrome-like cohort, MMP-1 concentrations discriminated infarct-like myocarditis and NSTEMI with an area under the receiver operating characteristic curve (AUC) of 0.95 (95% CI, 0.89-1.00), whereas high-sensitivity cardiac troponin T performed inferiorly (AUC, 0.74 [95% CI, 0.58-0.90]; P=0.012). Application of an optimal MMP-1 cutoff had 94.4% sensitivity (95% CI, 72.7%-99.9%) and 90.9% specificity (95% CI, 70.8%-98.9%) for the diagnosis of infarct-like myocarditis in this cohort. The AUC of PICP in this context was 0.82 (95% CI, 0.68-0.97). As assessed by likelihood ratio tests, incorporating MMP-1 or PICP with age and C-reactive protein into composite prediction models enhanced their diagnostic performance.

CONCLUSIONS

MMP-1 and PICP could potentially be useful biomarkers for differentiating between NSTEMI and infarct-like myocarditis in individuals with non-ST-segment-elevation acute coronary syndrome-like presentation, though further research is needed to validate their clinical applicability.

Unveiling myocardial microstructure shifts: exploring the impact of diabetes in stable CAD patients through CMR T1 mapping

BACKGROUND

This study investigates myocardial structural changes in stable coronary artery disease (CAD) patients with type 2 diabetes (T2D) using cardiac magnetic resonance (CMR) strain and T1 mapping.

METHODS

A total of 155 stable CAD patients underwent CMR examination, including left ventricular (LV) morphology and function assessment, late gadolinium enhancement (LGE), and feature tracking (CMR-FT) for LV global longitudinal, circumferential, and radial strain. T1 mapping with extracellular volume (ECV) evaluation was also performed.

RESULTS

Among the enrolled patients, 67 had T2D. Diabetic patients exhibited impaired LV strain and higher ECV compared to non-diabetics. Multivariate analysis identified T2D as an independent predictor of increased ECV and decreased strain.

CONCLUSIONS

CMR-based strain and T1 mapping highlighted impaired myocardial contractility, elevated ECV, and potential interstitial fibrosis in diabetic patients with stable CAD. This suggests a significant impact of diabetes on myocardial health beyond CAD, emphasizing the importance of a comprehensive assessment in these individuals.

TRIAL REGISTRATION

http://www.controlled-trials.com/ISRCTN09454308.

Aortic Regurgitation in Bicuspid Aortic Valve: The Role of Multimodality Imaging

The evaluation of aortic regurgitation (AR) in bicuspid valve (BAV) is still a challenge because of the eccentricity of the jet, which may under/overestimate the regurgitation. The commonly used echocardiography parameters (such as vena contracta, pressure half-time, etc.) may not be useful in this kind of patient. A multimodality approach combining echocardiography, cardiac MRI, cardiac CT, and advanced technologies applied to non-invasive cardiac imaging (e.g., 4D flow and strain imaging) may be useful to better quantify regurgitation and to select patients suitable for valve replacement. This review provides an overview of the most recent insights about cardiovascular imaging tools and their utility in BAV evaluation, focusing on chronic regurgitation. We describe the role of multimodality imaging in both diagnosis and risk assessment of this disease, pointing out the advantages and disadvantages of the imaging techniques, aiming to provide a guide to clinicians and cardiovascular imaging specialists in choosing the best imaging tools to use.

Mitral Annulus Disjunction in consecutive patients undergoing Cardiac Magnetic Resonance: where is the boundary between normality and disease?

BACKGROUND

The presence of mitral annulus disjunction (MAD) has been considered a high-risk feature for sudden cardiac death based on selected study populations. We aimed to assess the prevalence of MAD in consecutive patients undergoing clinically-indicated Cardiac Magnetic Resonance (CMR), its association with ventricular arrhythmias, Mitral Valve Prolapse (MVP), and other CMR features.

METHODS

This single-center retrospective study included consecutive patients referred to CMR at our Institution between June 2021 and November 2021. The MAD was defined as a ≥1mm displacement between the left atrial wall-mitral valve leaflet junction and the left ventricular wall during end-systole. The MAD extent was defined as the maximum longitudinal displacement. Associates of MAD were evaluated at uni- and multi-variariable regression analysis. A study endpoint including (aborted) sudden cardiac death, unexplained syncope, and sustained ventricular tachycardia was evaluated at 12-month follow-up.

RESULTS

Four-hundred-forty-one patients (55±18 years, 61% males) were included, and 29 (7%) had MVP. The prevalence of MAD ≥1mm, 4mm, and 6mm were 214 (49%), 63 (14%), and 15 (3%), respectively. Patients with MVP showed a higher prevalence of MAD greater than 1mm (90% vs. 46%; p<0.001), 4mm (48% vs. 12%; p<0.001), and 6mm (10% vs. 3%; p=0.03), and a greater MAD extent (4.2mm, 3.0-5.7mm vs. 2.8mm, 1.9-4.0mm; p<0.001) than patients without MVP. The MVP was the only morpho-functional abnormality associated with MAD at multivariable analysis (p<0.001). A high burden of ventricular ectopic beats at baseline Holter-ECG was associated with MAD ≥4mm and MAD extent (p<0.05). The presence of MAD ≥1mm (0.9% vs. 1.8%; p=0.46), MAD ≥4mm (1.6% vs. 1.3%; p=0.87), or MVP (3.5% vs. 1.2%; p=0.32) were not associated with the study endpoint, whereas patients with MAD ≥6mm showed a trend towards a higher likelihood of the study endpoint (6.7% vs. 1.2%; p=0.07).

CONCLUSIONS

A MAD of limited entity was common in consecutive patients undergoing CMR. Patients with MVP showed higher prevalence and greater extent of MAD. Extended MAD was rarer and showed association with ventricular arrhythmias at baseline. The mid-term prognosis of MAD seems benign, however prospective studies are warranted to search for potential "malignant MAD extents" to improve patients' risk stratification.

Multiparametric myocardial mapping using cardiac magnetic resonance imaging in healthy dogs: Reproducibility, repeatability, and differences across slices, segments, and sequences

Myocardial mapping in humans has been widely studied and applied to understand heart disease, facilitate early diagnosis, and determine therapeutic targets; however, the reproducibility, repeatability, and protocol-dependent differences in myocardial mapping in dogs remain unknown, which limits its application in dogs. This study investigated the reproducibility and test-retest repeatability of myocardial mapping in dogs and evaluated the differences according to slice, segment, and sequence. Precontrast T1 (native T1), T2 (T2), and T2* relaxation time (T2*), and extracellular volume (ECV) were measured at the base, midventricle, and apex of the left ventricle in six healthy beagles. To compare the sequences, the saturation recovery-based (SMART1) and inversion recovery-based (MOLLI) sequences were used for native T1 and ECV mapping. The intraclass correlation coefficient was measured to evaluate reproducibility and repeatability using the coefficient of variation and Bland-Altman analysis. All parameters showed good to excellent intra- and interobserver reproducibility and test-retest repeatability. The apex slice showed the lowest repeatability among the slices, whereas ECV had the lowest repeatability among the parameters. Native T1, ECV, and T2* did not differ according to slice, but T2 significantly increased from the base to the apex. Native T1 was significantly higher in SMART1 than in MOLLI, whereas ECV did not differ between the two sequences. Our results suggest that myocardial mapping is applicable in dogs with high reproducibility and repeatability, although slice and sequence differences should be considered. This study can serve as a guide for myocardial mapping studies in dogs with heart disease.

Potential prognostic impact of left-ventricular global longitudinal strain in analysis of whole-heart myocardial mechanics in nonischemic dilated cardiomyopathy

Cardiac magnetic resonance (CMR) feature-tracking (FT) has an important diagnostic role in non-ischemic dilated cardiomyopathy (NIDCM). To date, the relationship between whole-heart myocardial mechanics by CMR and early primary outcomes in NIDCM has not been elucidated. patients with NIDCM were eligible for this study. CMR-FT was used to analyze whole-heart myocardial mechanics. The primary outcomes were a composite of heart failure (HF) death, heart transplantation (HT), and hospitalization for HF worsening (WHF) after 1-year since diagnosis. 98 patients were included. During a 1-year follow-up, a worse prognosis occurred in 32 patients (30 hospitalizations for WHF, 8 deaths, and 3 HT). The left ventricular (LV) global longitudinal systolic strain (GLS), left ventricular global circumferential strain (LV GCS), strains of right ventricle and both atria were significantly reduced in patients with events vs. those without (GLS - 8.0 ± 3.4 vs. - 12.1 ± 4.5, p < 0.001; GCS - 13.0 ± 6.4 vs. - 18.3 ± 7.1, p < 0.001; right ventricular (RV) GLS - 12.1 ± 4.9 vs. - 17.4 ± 6.4, p < 0.001; left atrial longitudinal strain 7.5 ± 3.8 vs. 15.1 ± 12.3, p < 0.001; right atrial longitudinal strain 11.0 ± 6.7 vs. 17.2 ± 8.0, p < 0.001). Left ventricular ejection fraction (LVEF) was significantly higher in patients with better prognosis (22.7 ± 8.7 vs. 33.56 ± 10.4, p < 0.001). Multivariate regression analysis revealed LV GLS as an independent predictor of a worse prognosis (OR 0.787, CI 95% 0.697-0.890, p < 0.001). reduction of LV GLS showed the strongest predictive value for the composite outcome of WHF, HT, and HF death.

Variations in threshold values for border zone and dense scar produce significant changes in scar parameters obtained by ADAS-3D

BACKGROUND

ADAS-3D software elaborates cardiac magnetic resonance (CMR) images to obtain a quantitative evaluation of dense scar and border zone (BZ), including BZ channels, which can be useful for ventricular tachycardia ablation and risk stratification. However, most prior reports with ADAS-3D used flexible thresholds (60% ± 5% and 40% ± 5% of maximum pixel signal intensity) to define dense scar and BZ. The impact of such variations of the threshold values on the measurements obtained with ADAS-3D is unknown.

OBJECTIVE

This study aimed to quantify the degree of change in ADAS-3D measurements when different thresholds for dense scar and BZ are employed.

METHODS

A single-center retrospective observational cohort study including 87 consecutive patients with previous myocardial infarction who underwent CMR was conducted. ADAS-3D software semiautomatically processed CMR sequences. We compared the scar measurements obtained with the 9 possible combinations of thresholds (55%/60%/65% and 35%/40%/45% of maximum pixel signal intensity).

RESULTS

The overall comparison between thresholds showed highly significant differences (P < .001) in all scar parameters. Not a single patient maintained the same number of BZ channels with all the thresholds settings. A percentage difference of up to 200% in BZ channel numbers and channel mass was observed in all 36 comparisons. An absolute difference of up to 10 channels was also recorded. Of note, the highest median channel mass (obtained with the thresholds 35-65) was 59-fold higher compared with the lowest one (obtained with the 45-55 cutoffs).

CONCLUSION

Variations in threshold values result in statistically significant and high-magnitude changes in the quantification of scar parameters by ADAS-3D.

Base-to-apex Gradient Pattern Assessed by Cardiovascular Magnetic Resonance in Takotsubo Cardiomyopathy

OBJECTIVES

The purpose of this study was to investigate the base-to-apex gradient strain pattern as a noncontrast cardiovascular magnetic resonance (CMR) parameter in patients with Takotsubo cardiomyopathy (TTC) and determine whether this pattern may help discriminate TTC from patients with anterior myocardial infarction (AMI).

MATERIALS AND METHODS

A total of 80 patients were included in the analysis: 30 patients with apical ballooning TTC and 50 patients with AMI. Global and regional ventricular function, including longitudinal (LS), circumferential (CS), and radial strain (RS), were assessed using CMR. The base-to-apex LS, RS, and CS gradients, defined as the peak gradient difference between averaged basal and apical strain, were calculated.

RESULTS

The base-to-apex RS gradient was impaired in TTC patients compared with the AMI group (14.04 ± 15.50 vs. -0.43 ± 11.59, P =0.001). Conversely, there were no significant differences in the base-to-apex LS and CS gradients between the AMI group and TTC patients (0.14 ± 2.71 vs. -1.5 ± 3.69, P =0.054: -0.99 ± 6.49 vs. ±1.4 ± 5.43, P =0.47, respectively). Beyond the presence and extension of LGE, base-to-apex RS gradient was the only independent discriminator between TTC and AMI (OR 1.28; 95% CI 1.08, 1.52, P =0.006) in multivariate logistic regression analysis.

CONCLUSION

The findings of this study suggest that the pattern of regional myocardial strain impairment could serve as an additional noncontrast CMR tool to refine the diagnosis of TTC. A pronounced base-to-apex RS gradient may be a specific left ventricle strain pattern of TTC.

Assessment of Pulmonary Arteries Hemodynamics and Its Relationship With Cardiac Remodeling and Myocardial Fibrosis in Athletes With Four-Dimensional Flow MRI

BACKGROUND

Exercise-induced cardiac remodeling (CR) and myocardial fibrosis (MF) can increase cardiovascular risk in athletes. Early detection of pulmonary arterial hemodynamics parameters among athletes may be beneficial in optimizing the frequency of clinical follow-ups.

PURPOSE

To analyze the hemodynamics of pulmonary arteries and its relationship with CR and MF in athletes using four-dimensional (4D) flow MRI.

STUDY TYPE

Prospective.

POPULATION

One hundred twenty-one athletes (median age, 24 years; mean exercise per week 10 hours, for mean of 5 years) and twenty-one sedentary healthy controls (median age, 25 years; exercise per week <3 hours, irregular pattern).

FIELD STRENGTH/SEQUENCE

True fast imaging with steady state free precession, time-resolved 3D Cartesian phase-contrast, and phase sensitive inversion recovery late gadolinium enhancement sequences at 3.0 T.

ASSESSMENT

CR was defined as any cardiac parameters exceeding the 99th percentile upper reference limits, encompassing ventricular function, bi-atrium and bi-ventricle diameters, and ventricular wall thickness. MF was visually evaluated by three independent radiologists. 4D flow parameters were assessed in the main, right, and left pulmonary arteries (MPA, RPA, and LPA, respectively) and compared between different groups. Four machine learning (ML) models were developed to differentiate between athletes with and without CR and/or MF.

STATISTICAL TESTS

Univariate analysis was used to compare groups. Area under the receiver operating characteristic curve (AUC) was used to assess the performance of the ML models.

RESULTS

Athletes had significantly higher WSSmax in the MPA, RPA, and LPA than controls. Athletes with CR and/or MF (N = 30) had significantly lower RPmax from MPA to RPA than those without (N = 91). Among the ML models, the gradient boosting machine model had the highest performance, with an AUC of 0.90.

CONCLUSION

The pulmonary arterial hemodynamics parameters could differentiate CR and/or MF in athletes, which may be potential to assist in optimizing frequency of follow-up.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 2.

Additional Impact of Aortic Regurgitation on Left Ventricular Strain and Remodeling in Essential Hypertension Patients Evaluated Using MRI

BACKGROUND

Understanding the impact of aortic regurgitation (AR) on hypertensive patients' hearts is important.

PURPOSE

To assess left ventricular (LV) strain and structure in hypertensive patients and investigate the relationship with AR severity.

STUDY TYPE

Retrospective.

POPULATION

263 hypertensive patients (99 with AR) and 62 controls, with cardiac MRI data.

FIELD STRENGTH/SEQUENCE

Balanced steady-state free precession (bSSFP) sequence at 3.0T.

ASSESSMENT

AR was classified as mild, moderate, or severe based on echocardiographic findings. LV geometry was classified as normal, concentric remodeling, eccentric hypertrophy, or concentric hypertrophy based on MRI assessment of LV mass/volume ratio and LV Mass index (LVMI). LV global radial peak strain (GRPS), global circumferential peak strain (GCPS), and global longitudinal peak strain (GLPS) were obtained by post-processing bSSFP cine datasets using commercial software.

STATISTICAL TESTS

ANOVA, Kruskal-Wallis test, Spearman's correlation coefficients (r), chi-square test, and multivariable linear regression analysis. A P value <0.05 was considered statistically significant.

RESULTS

Hypertensive patients with AR had significantly lower LV myocardial strain and higher LVMI than the group without AR (GRPS 26.25 ± 12.23 vs. 34.53 ± 9.85, GCPS -17.4 ± 5.84 vs. -20.57 ± 3.57, GLPS -9.86 ± 4.08 vs. -12.95 ± 2.94, LVMI 90.56 ± 38.56 vs.58.84 ± 17.55). Of the 99 patients with AR, 56 had mild AR, 26 had moderate AR and 17 had severe AR. The degree of AR was significantly negatively correlated to the absolute values of LV GRPS, GCPS and GLPS (r = -0.284 - -0.416). LV eccentric hypertrophy increased significantly with AR severity (no AR 21.3%, mild AR 42.9%, moderate AR 73.1%, severe AR 82.4%). In multivariable analysis, the degree of AR was an independent factor affecting LV global strain and LVMI even after considering confounding factors (β values for global myocardial strain were -0.431 to -0.484, for LVMI was 0.646).

DATA CONCLUSION

Increasing AR severity leads to decreased cardiac function and worse ventricular geometric phenotypes in hypertensive patients.

LEVEL OF EVIDENCE

4 TECHNICAL EFFICACY: Stage 3.

Exercise-induced changes in left ventricular strain are affected by interleukin-6 activity: An exploratory analysis of a randomised-controlled trial in humans with abdominal obesity

Whilst the exercise-induced myokine interleukin-6 (IL-6) plays a beneficial role in cardiac structural adaptations, its influence on exercise-induced functional cardiac outcomes remains unknown. We hypothesised that IL-6 activity is required for exercise-induced improvements in left ventricular global longitudinal strain (LV GLS). In an exploratory study 52 individuals with abdominal obesity were randomised to 12 weeks' high-intensity exercise or no exercise in combination with IL-6 receptor inhibition (IL-6i) or placebo. LV strain and volume measurements were assessed by cardiac magnetic resonance. Exercise improved LV GLS by -5.4% [95% CI: -9.1% to -1.6%] (P = 0.007). Comparing the change from baseline in LV GLS in the exercise + placebo group (-4.8% [95% CI: -7.4% to -2.2%]; P < 0.0004) to the exercise + IL-6i group (-1.1% [95% CI: -3.8% to 1.6%]; P = 0.42), the exercise + placebo group changed -3.7% [95% CI: -7.4% to -0.02%] (P = 0.049) more than the exercise + IL6i group. However, the interaction effect between exercise and IL-6i was insignificant (4.5% [95% CI: -0.8% to 9.9%]; P = 0.09). Similarly, the exercise + placebo group improved LV global circumferential strain by -3.1% [95% CI: -6.0% to -0.1%] (P = 0.04) more compared to the exercise + IL-6i group, yet we found an insignificant interaction between exercise and IL-6i (4.2% [95% CI: -1.8% to 10.3%]; P = 0.16). There was no effect of IL-6i on exercise-induced changes to volume rates. This study underscores the importance of IL-6 in improving LV GLS in individuals with abdominal obesity suggesting a role for IL-6 in cardiac functional exercise adaptations.

Ethnicity differences in geometric remodelling and myocardial composition in hypertension unveiled by cardiovascular magnetic resonance

AIMS

Hypertensive patients of African ancestry (Afr-a) have higher incidences of heart failure and worse clinical outcomes than hypertensive patients of European ancestry (Eu-a), yet the underlying mechanisms remain misunderstood. This study investigated right (RV) and left (LV) ventricular remodelling alongside myocardial tissue derangements between Afr-a and Eu-a hypertensives.

METHODS AND RESULTS

63 Afr-a and 47 Eu-a hypertensives underwent multi-parametric cardiovascular magnetic resonance. Biventricular volumes, mass, function, mass/end-diastolic volume (M/V) ratios, T2 and pre-/post-contrast T1 relaxation times, synthetic extracellular volume, and myocardial fibrosis (MF) were measured. 3D shape modelling was implemented to delineate ventricular geometry. LV and RV mass (indexed to body-surface-area) and M/V ratio were significantly greater in Afr-a than Eu-a hypertensives (67.1 ± 21.7 vs. 58.3 ± 16.7 g/m2, 12.6 ± 3.48 vs. 10.7 ± 2.71 g/m2, 0.79 ± 0.21 vs. 0.70 ± 0.14 g/mL, and 0.16 ± 0.04 vs. 0.13 ± 0.03 g/mL, respectively; P < 0.03). Afr-a patients showed greater basal interventricular septum thickness than Eu-a patients, influencing LV hypertrophy and RV cavity changes. This biventricular remodelling was associated with prolonged T2 relaxation time (47.0 ± 2.2 vs. 45.7 ± 2.2 ms, P = 0.005) and higher prevalence (23% vs. 4%, P = 0.001) and extent of MF [2.3 (0.6-14.3) vs. 1.6 (0.9-2.5) % LV mass, P = 0.008] in Afr-a patients. Multivariable linear regression showed that modifiable cardiovascular risk factors and greater end-diastolic volume, but not ethnicity, were independently associated with greater LV mass.

CONCLUSION

Afr-a hypertensives had distinctive biventricular remodelling, including increased RV mass, septal thickening and myocardial tissue abnormalities compared with Eu-a hypertensives. From this study, modifiable cardiovascular risk factors and ventricular geometry, but not ethnicity, were independently associated with greater LV myocardial mass.

Three-Dimensional Feature Tracking Study of Healthy Chinese Ventricle by Cardiac Magnetic Resonance

PURPOSE

Myocardial strain, as a crucial quantitative indicator of myocardial deformation, can detect the changes of cardiac function earlier than parameters such as ejection fraction (EF). It has reported that cardiac magnetic resonance(CMR) and post-processing software possess the ability to obtain the stability and repeatability strain values. Recently, the normal strain values range of people are debatable, especially in the Chinese population. Therefore, we aim to explore the ventricular characteristics and the myocardial strain values of the Chinese people by using the cardiac magnetic resonance feature tracking (CMR-FT). Additionally, we attempted to use the myocardial and chordae tendineae contours to calculate the ventricular volumes by the CMR-FT. This study may provide valuable insights into the application of CMR-FT in tracking the ventricular characteristics and myocardial strain for Chinese population, especially in suggesting an referable myocardial strain parameters of the Chinese.

METHODS

A total of 109 healthy Chinese individuals (age range: 18 to 58 years; 52 males and 57 females) underwent 3.0T CMR to acquire the cardiac images. The commercial post-processing software was employed to analyse the image sequence by semi-automatic processing, then the biventricular morphology (End-Diastolic Volume, EDV; EDV/Body Surface Area, EDV/BSA), function(EF; Cardiac Output, CO; Cardiac Index, CI) and strain(Radial Strain, RS; Circumferential Strain, CS; Longitudinal Strain, LS) values were obtained.The biventricular myocardial strain values were stratified according to the age and gender. The Left Ventricular( LV base, mid, apex) and myocardial strain values of three coronary artery areas were calculated based on the the strain value of LV American Heart Association(AHA) 16 segments.

RESULTS

It was shown that the females had larger LV globe strain values compared with the males (LVGPRS: 42.0 ± 8.5 versus 33.6 ± 6.2%, P < 0.001; LVGPCS: -21.2 ± 2.1 versus - 19.7 ± 2.3%, P < 0.001; LVGPLS: -16.4 ± 2.6 versus - 14.6 ± 2.2%, P < 0.001;). Moreover, the differences in RS, CS, and LS among the LV myocardium 16 segments were obvious. However, the right ventricle (RV) strain values showed non-normal distribution in the volunteers of this research.

CONCLUSIONS

Here, we successfully tracked the characteristics of bilateral ventricles in healthy Chinese populations through using the 3.0T CMR. We confirmed that there was a gender difference in LV Globe Strain values. In addition, we obtained strain values for each myocardial segment of the LV and different coronary artery regions based on the AHA 16 segments method, Our results also showed that the RV strain values with a non-normal distribution, and RV global strain values were not related to the gender and age. Furthermore, LVGPRS, LVGPLS, and RVGPRS were significantly correlated with BMI, CO, CI, and EDV in the Chinese population.

Assessment of subclinical LV myocardial dysfunction in T2DM patients with diabetic peripheral neuropathy: a cardiovascular magnetic resonance study

BACKGROUND

Diabetic peripheral neuropathy (DPN) is the most prevalent complication of diabetes, and has been demonstrated to be independently associated with cardiovascular events and mortality. This aim of this study was to investigate the subclinical left ventricular (LV) myocardial dysfunction in type 2 diabetes mellitus (T2DM) patients with and without DPN.

METHODS

One hundred and thirty T2DM patients without DPN, 61 patients with DPN and 65 age and sex-matched controls who underwent cardiovascular magnetic resonance (CMR) imaging were included, all subjects had no symptoms of heart failure and LV ejection fraction ≥ 50%. LV myocardial non-infarct late gadolinium enhancement (LGE) was determined. LV global strains, including radial, circumferential and longitudinal peak strain (PS) and peak systolic and diastolic strain rates (PSSR and PDSR, respectively), were evaluated using CMR feature tracking and compared among the three groups. Multivariable linear regression analyses were performed to determine the independent factors of reduced LV global myocardial strains in T2DM patients.

RESULTS

The prevalence of non-infarct LGE was higher in patients with DPN than those without DPN (37.7% vs. 19.2%, p = 0.008). The LV radial and longitudinal PS (radial: 36.60 ± 7.24% vs. 33.57 ± 7.30% vs. 30.72 ± 8.68%; longitudinal: - 15.03 ± 2.52% vs. - 13.39 ± 2.48% vs. - 11.89 ± 3.02%), as well as longitudinal PDSR [0.89 (0.76, 1.05) 1/s vs. 0.80 (0.71, 0.93) 1/s vs. 0.77 (0.63, 0.87) 1/s] were decreased significantly from controls through T2DM patients without DPN to patients with DPN (all p < 0.001). LV radial and circumferential PDSR, as well as circumferential PS were reduced in both patient groups (all p < 0.05), but were not different between the two groups (all p > 0.05). Radial and longitudinal PSSR were decreased in patients with DPN (p = 0.006 and 0.003, respectively) but preserved in those without DPN (all p > 0.05). Multivariable linear regression analyses adjusting for confounders demonstrated that DPN was independently associated with LV radial and longitudinal PS (β = - 3.025 and 1.187, p = 0.014 and 0.003, respectively) and PDSR (β = 0.283 and - 0.086, p = 0.016 and 0.001, respectively), as well as radial PSSR (β = - 0.266, p = 0.007).

CONCLUSIONS

There was more severe subclinical LV dysfunction in T2DM patients complicated with DPN than those without DPN, suggesting further prospective study with more active intervention in this cohort of patients.

Impact of pretransplant T2DM on left ventricular deformation and myocardial perfusion in heart transplanted recipients: a 3.0 T cardiac magnetic resonance study

BACKGROUND

Pretransplant type 2 diabetes mellitus (T2DM) is associated with increased cardiovascular and all-cause mortality after heart transplant (HT), but the underlying causes of this association remain unclear. The purpose of this research was to examine the impact of T2DM on left ventricular (LV) myocardial deformation and myocardial perfusion following heart transplantation using cardiovascular magnetic resonance imaging.

METHODS

We investigated thirty-one HT recipients with pretransplant T2DM [HT(DM+)], thirty-four HT recipients without pretransplant T2DM [HT(DM-)] and thirty-six controls. LV myocardial strains, including the global longitudinal, radial, and circumferential strain (GLS, GRS and GCS, respectively), were calculated and compared among groups, as were resting myocardial perfusion indices, which included time to peak myocardial signal intensity (TTM), maximum signal intensity (MaxSI), and Upslope. The relationships between LV strain parameters or perfusion indices and biochemical indicators were determined through Spearman's analysis. The impact of T2DM on LV strains in HT recipients was assessed using multivariable linear regression analyses with backward stepwise selection.

RESULTS

In the HT(DM+) group, the LV GLS, GRS, and GCS exhibited significantly lower magnitudes than those in both the HT(DM-) and control groups. TTM was higher in the HT(DM+) group than in both the HT(DM-) and control groups, while no significant differences were observed among the groups regarding Upslope and MaxSI. There was a negative correlation between glycated hemoglobin and the magnitude of strains (longitudinal, r = - 0.399; radial, r = - 0.362; circumferential, r = - 0.389) (all P < 0.05), and a positive correlation with TTM (r = 0.485, P < 0.001). Regression analyses that included both pretransplant T2DM and perfusion indices revealed that pretransplant T2DM, rather than perfusion indices, was an independent determinant of LV strain (β = longitudinal, - 0.508; radial, - 0.370; circumferential, - 0.371) (all P < 0.05).

CONCLUSION

In heart transplant recipients, pretransplant T2DM has a detrimental effect on subclinical left ventricular systolic function and could potentially impact myocardial microcirculation following HT.

Diagnostic efficacy of complexity metrics from cardiac MRI myocardial segmental motion curves in detecting late gadolinium enhancement in myocardial infarction patients

Background

Myocardial segmental motion is associated with cardiovascular pathology, often assessed through myocardial strain features. The stability of the motion can be influenced by myocardial fibrosis. This research aimed to explore the complexity metrics (CM) of myocardial segmental motion curves, observe their correlation with late gadolinium enhancement (LGE) transmural extension (TE), and assess diagnostic efficacy combined with segmental strains in different TE segments.

Methods

We included 42 myocardial infarction patients, dividing images into 672 myocardial segments (208 remote, 384 viable, and 80 unviable segments based on TE). Radial and circumferential segmental strain, along with CM for motion curves, were extracted. Correlation between CM and LGE, as well as the potential distinguishing role of CM, was evaluated using Pearson correlation, univariate linear regression (F-test), multivariate regression analysis (T-test), area under curve (AUC), machine learning models, and DeLong test.

Results

All CMs showed significant linear correlation with TE (P < 0.001). Six CMs were correlated with TE (r > 0.3), with radial frequency drift (FD) displayed the strongest correlation (r = 0.496, P < 0.001). Radial and circumferential FD significantly differed in higher TE myocardium than in remote segments (P < 0.05). Radial FD had practical diagnostic efficacy (remote vs. unviable AUC = 0.89, viable vs. unviable AUC = 0.77, remote vs. viable AUC = 0.65). Combining CM with segmental strain features boosted diagnostic efficacy than models using only segmental strain features (DeLong test, P < 0.05).

Conclusions

The CM of myocardial motion curves has been associated with LGE infarction, and combining CM with strain features improves the diagnosis of different myocardial LGE infarction degrees.

Cardiovascular Magnetic Resonance Before Invasive Coronary Angiography in Suspected Non-ST-Segment Elevation Myocardial Infarction

BACKGROUND

In suspected non-ST-segment elevation myocardial infarction (NSTEMI), this presumed diagnosis may not hold true in all cases, particularly in patients with nonobstructive coronary arteries (NOCA). Additionally, in multivessel coronary artery disease, the presumed infarct-related artery may be incorrect.

OBJECTIVES

This study sought to assess the diagnostic utility of cardiac magnetic resonance (CMR) before invasive coronary angiogram (ICA) in suspected NSTEMI.

METHODS

A total of 100 consecutive stable patients with suspected acute NSTEMI (70% male, age 62 ± 11 years) prospectively underwent CMR pre-ICA to assess cardiac function (cine), edema (T2-weighted imaging, T1 mapping), and necrosis/scar (late gadolinium enhancement). CMR images were interpreted blinded to ICA findings. The clinical care and ICA teams were blinded to CMR findings until post-ICA.

RESULTS

Early CMR (median 33 hours postadmission and 4 hours pre-ICA) confirmed only 52% (52 of 100) of patients had subendocardial infarction, 15% transmural infarction, 18% nonischemic pathologies (myocarditis, Takotsubo and other forms of cardiomyopathies), and 11% normal CMR; 4% were nondiagnostic. Subanalyses according to ICA findings showed that, in patients with obstructive coronary artery disease (73 of 100), CMR confirmed only 84% (61 of 73) had MI, 10% (7 of 73) nonischemic pathologies, and 5% (4 of 73) normal. In patients with NOCA (27 of 100), CMR found MI in only 22% (6 of 27 true MI with NOCA), and reclassified the presumed diagnosis of NSTEMI in 67% (18 of 27: 11 nonischemic pathologies, 7 normal). In patients with CMR-MI and obstructive coronary artery disease (61 of 100), CMR identified a different infarct-related artery in 11% (7 of 61).

CONCLUSIONS

In patients presenting with suspected NSTEMI, a CMR-first strategy identified MI in 67%, nonischemic pathologies in 18%, and normal findings in 11%. Accordingly, CMR has the potential to affect at least 50% of all patients by reclassifying their diagnosis or altering their potential management.

Cardiac magnetic resonance imaging characterization of acute rejection in a porcine heterotopic heart transplantation model

Preclinical disease models are important for the advancement of therapeutics towards human clinical trials. One of the difficult tasks of developing a well-characterized model is having a reliable modality with which to trend the progression of disease. Acute rejection is one of the most devastating complications that can occur following organ transplantation. Specifically in cardiac transplantation, approximately 12% of patients will experience at least one episode of moderate or severe acute rejection in the first year. Currently, the gold standard for monitoring rejection in the clinical setting is to perform serial endomyocardial biopsies for direct histological assessment. However, this is difficult to reproduce in a porcine model of acute rejection in cardiac transplantation where the heart is heterotopically transplanted in an abdominal position. Cardiac magnetic resonance imaging is arising as an alternative for serial screening for acute rejection in cardiac transplantation. This is an exploratory study to create and define a standardized cardiac magnetic resonance screening protocol for characterizing changes associated with the presence of acute rejection in this preclinical model of disease. Results demonstrate that increases in T1 mapping, T2 mapping, left ventricular mass, and in late gadolinium enhancement are significantly correlated with presence of acute rejection.

Arrhythmic Mitral Valve Prolapse Phenotype: An Unsupervised Machine Learning Analysis Using a Multicenter Cardiac MRI Registry

Purpose To use unsupervised machine learning to identify phenotypic clusters with increased risk of arrhythmic mitral valve prolapse (MVP). Materials and Methods This retrospective study included patients with MVP without hemodynamically significant mitral regurgitation or left ventricular (LV) dysfunction undergoing late gadolinium enhancement (LGE) cardiac MRI between October 2007 and June 2020 in 15 European tertiary centers. The study end point was a composite of sustained ventricular tachycardia, (aborted) sudden cardiac death, or unexplained syncope. Unsupervised data-driven hierarchical k-mean algorithm was utilized to identify phenotypic clusters. The association between clusters and the study end point was assessed by Cox proportional hazards model. Results A total of 474 patients (mean age, 47 years ± 16 [SD]; 244 female, 230 male) with two phenotypic clusters were identified. Patients in cluster 2 (199 of 474, 42%) had more severe mitral valve degeneration (ie, bileaflet MVP and leaflet displacement), left and right heart chamber remodeling, and myocardial fibrosis as assessed with LGE cardiac MRI than those in cluster 1. Demographic and clinical features (ie, symptoms, arrhythmias at Holter monitoring) had negligible contribution in differentiating the two clusters. Compared with cluster 1, the risk of developing the study end point over a median follow-up of 39 months was significantly higher in cluster 2 patients (hazard ratio: 3.79 [95% CI: 1.19, 12.12], P = .02) after adjustment for LGE extent. Conclusion Among patients with MVP without significant mitral regurgitation or LV dysfunction, unsupervised machine learning enabled the identification of two phenotypic clusters with distinct arrhythmic outcomes based primarily on cardiac MRI features. These results encourage the use of in-depth imaging-based phenotyping for implementing arrhythmic risk prediction in MVP. Keywords: MR Imaging, Cardiac, Cardiac MRI, Mitral Valve Prolapse, Cluster Analysis, Ventricular Arrhythmia, Sudden Cardiac Death, Unsupervised Machine Learning Supplemental material is available for this article. © RSNA, 2024.

Correlation of Noninvasive Cardiac MRI Measures of Left Ventricular Myocardial Function and Invasive Pressure-Volume Parameters in a Porcine Ischemia-Reperfusion Model

Purpose To assess the correlation between noninvasive cardiac MRI-derived parameters with pressure-volume (PV) loop data and evaluate changes in left ventricular function after myocardial infarction (MI). Materials and Methods Sixteen adult female swine were induced with MI, with six swine used as controls and 10 receiving platelet-derived growth factor-AB (PDGF-AB). Load-independent measures of cardiac function, including slopes of end-systolic pressure-volume relationship (ESPVR) and preload recruitable stroke work (PRSW), were obtained on day 28 after MI. Cardiac MRI was performed on day 2 and day 28 after infarct. Global longitudinal strain (GLS) and global circumferential strain (GCS) were measured. Ventriculo-arterial coupling (VAC) was derived from PV loop and cardiac MRI data. Pearson correlation analysis was performed. Results GCS (r = 0.60, P = .01), left ventricular ejection fraction (LVEF) (r = 0.60, P = .01), and cardiac MRI-derived VAC (r = 0.61, P = .01) had a significant linear relationship with ESPVR. GCS (r = 0.75, P < .001) had the strongest significant linear relationship with PRSW, followed by LVEF (r = 0.67, P = .005) and cardiac MRI-derived VAC (r = 0.60, P = .01). GLS was not significantly correlated with ESPVR or PRSW. There was a linear correlation (r = 0.82, P < .001) between VAC derived from cardiac MRI and from PV loop data. GCS (-3.5% ± 2.3 vs 0.5% ± 1.4, P = .007) and cardiac MRI-derived VAC (-0.6 ± 0.6 vs 0.3 ± 0.3, P = .001) significantly improved in the animals treated with PDGF-AB 28 days after MI compared with controls. Conclusion Cardiac MRI-derived parameters of MI correlated with invasive PV measures, with GCS showing the strongest correlation. Cardiac MRI-derived measures also demonstrated utility in assessing therapeutic benefit using PDGF-AB. Keywords: Cardiac MRI, Myocardial Infarction, Pressure Volume Loop, Strain Imaging, Ventriculo-arterial Coupling Supplemental material is available for this article. © RSNA, 2024.

Cardiac magnetic resonance imaging in systemic sclerosis: Heart involvement in high-resolution

Cardiac magnetic resonance imaging (CMR) is the gold-standard non-invasive method of assessing cardiac structure and function, including tissue characterisation. In systemic sclerosis (SSc), heart involvement (SHI) is a leading cause of mortality yet remains poorly understood. SHI is underestimated by conventional echocardiography, and CMR provides an important opportunity to better identify and quantify subtle myocardial changes including oedema and fibrosis. This review summarises current CMR techniques, the role of CMR in SSc and SHI, and the opportunities to further our understanding of its pathogenesis and management.

Sex-based differences in the phenotypic expression and prognosis of idiopathic non-ischaemic cardiomyopathy: a cardiovascular magnetic resonance study

AIMS

We sought to characterize sex-related differences in cardiovascular magnetic resonance-based cardiovascular phenotypes and prognosis in patients with idiopathic non-ischaemic cardiomyopathy (NICM).

METHODS AND RESULTS

Patients with NICM enrolled in the Cardiovascular Imaging Registry of Calgary (CIROC) between 2015 and 2021 were identified. Z-score values for chamber volumes and function were calculated as standard deviation from mean values of 157 sex-matched healthy volunteers, ensuring reported differences were independent of known sex-dependencies. Patients were followed for the composite outcome of all-cause mortality, heart failure admission, or ventricular arrhythmia. A total of 747 patients were studied, 531 (71%) males. By Z-score values, females showed significantly higher left ventricular (LV) ejection fraction (EF; median difference 1 SD) and right ventricular (RV) EF (difference 0.6 SD) with greater LV mass (difference 2.1 SD; P < 0.01 for all) vs. males despite similar chamber volumes. Females had a significantly lower prevalence of mid-wall striae (MWS) fibrosis (22% vs. 34%; P < 0.001). Over a median follow-up of 4.7 years, 173 patients (23%) developed the composite outcome, with equal distribution in males and females. LV EF and MWS were significant independent predictors of the outcome (respective HR [95% CI] 0.97 [0.95-0.99] and 1.6 [1.2-2.3]; P = 0.003 and 0.005). There was no association of sex with the outcome.

CONCLUSION

In a large contemporary cohort, NICM was uniquely expressed in females vs. males. Despite similar chamber dilation, females demonstrated greater concentric remodelling, lower reductions in bi-ventricular function, and a lower burden of replacement fibrosis. Overall, their prognosis remained similar to male patients with NICM.

Deep learning for automatic volumetric segmentation of left ventricular myocardium and ischaemic scar from multi-slice late gadolinium enhancement cardiovascular magnetic resonance

AIMS

This study details application of deep learning for automatic volumetric segmentation of left ventricular (LV) myocardium and scar and automated quantification of myocardial ischaemic scar burden from late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR).

METHODS AND RESULTS

We included 501 images and manual segmentations of short-axis LGE-CMR from over 20 multinational sites, from which 377 studies were used for training and 124 studies from unique participants for internal validation. A third test set of 52 images was used for external evaluation. Three models, U-Net, Cascaded U-Net, and U-Net++, were trained with a novel adaptive weighted categorical cross-entropy loss function. Model performance was evaluated using concordance correlation coefficients (CCCs) for LV mass and per cent myocardial scar burden. Cascaded U-Net was found to be the best model for the quantification of LV mass and scar percentage. The model exhibited a mean difference of -5 ± 23 g for LV mass, -0.4 ± 11.2 g for scar mass, and -0.8 ± 7% for per cent scar. CCC were 0.87, 0.77, and 0.78 for LV mass, scar mass, and per cent scar burden, respectively, in the internal validation set and 0.75, 0.71, and 0.69, respectively, in the external test set. For segmental scar mass, CCC was 0.74 for apical scar, 0.91 for mid-ventricular scar, and 0.73 for basal scar, demonstrating moderate to strong agreement.

CONCLUSION

We successfully trained a convolutional neural network for volumetric segmentation and analysis of LV scar burden from LGE-CMR images in a large, multinational cohort of participants with ischaemic scar.

Tricuspid valve flow measurement using a deep learning framework for automated valve-tracking 2D phase contrast

PURPOSE

Tricuspid valve flow velocities are challenging to measure with cardiovascular MR, as the rapidly moving valvular plane prohibits direct flow evaluation, but they are vitally important to diastolic function evaluation. We developed an automated valve-tracking 2D method for measuring flow through the dynamic tricuspid valve.

METHODS

Nine healthy subjects and 2 patients were imaged. The approach uses a previously trained deep learning network, TVnet, to automatically track the tricuspid valve plane from long-axis cine images. Subsequently, the tracking information is used to acquire 2D phase contrast (PC) with a dynamic (moving) acquisition plane that tracks the valve. Direct diastolic net flows evaluated from the dynamic PC sequence were compared with flows from 2D-PC scans acquired in a static slice localized at the end-systolic valve position, and also ventricular stroke volumes (SVs) using both planimetry and 2D PC of the great vessels.

RESULTS

The mean tricuspid valve systolic excursion was 17.8 ± 2.5 mm. The 2D valve-tracking PC net diastolic flow showed excellent correlation with SV by right-ventricle planimetry (bias ± 1.96 SD = -0.2 ± 10.4 mL, intraclass correlation coefficient [ICC] = 0.92) and aortic PC (-1.0 ± 13.8 mL, ICC = 0.87). In comparison, static tricuspid valve 2D PC also showed a strong correlation but had greater bias (p = 0.01) versus the right-ventricle SV (10.6 ± 16.1 mL, ICC = 0.61). In most (8 of 9) healthy subjects, trace regurgitation was measured at begin-systole. In one patient, valve-tracking PC displayed a high-velocity jet (380 cm/s) with maximal velocity agreeing with echocardiography.

CONCLUSION

Automated valve-tracking 2D PC is a feasible route toward evaluation of tricuspid regurgitant velocities, potentially solving a major clinical challenge.

The Tricuspid Valve: A Review of Pathology, Imaging, and Current Treatment Options: A Scientific Statement From the American Heart Association

Tricuspid valve disease is an often underrecognized clinical problem that is associated with significant morbidity and mortality. Unfortunately, patients will often present late in their disease course with severe right-sided heart failure, pulmonary hypertension, and life-limiting symptoms that have few durable treatment options. Traditionally, the only treatment for tricuspid valve disease has been medical therapy or surgery; however, there have been increasing interest and success with the use of transcatheter tricuspid valve therapies over the past several years to treat patients with previously limited therapeutic options. The tricuspid valve is complex anatomically, lying adjacent to important anatomic structures such as the right coronary artery and the atrioventricular node, and is the passageway for permanent pacemaker leads into the right ventricle. In addition, the mechanism of tricuspid pathology varies widely between patients, which can be due to primary, secondary, or a combination of causes, meaning that it is not possible for 1 type of device to be suitable for treatment of all cases of tricuspid valve disease. To best visualize the pathology, several modalities of advanced cardiac imaging are often required, including transthoracic echocardiography, transesophageal echocardiography, cardiac computed tomography, and cardiac magnetic resonance imaging, to best visualize the pathology. This detailed imaging provides important information for choosing the ideal transcatheter treatment options for patients with tricuspid valve disease, taking into account the need for the lifetime management of the patient. This review highlights the important background, anatomic considerations, therapeutic options, and future directions with regard to treatment of tricuspid valve disease.

A study on the application of radiomics based on cardiac MR non-enhanced cine sequence in the early diagnosis of hypertensive heart disease

BACKGROUND

The prevalence of hypertensive heart disease (HHD) is high and there is currently no easy way to detect early HHD. Explore the application of radiomics using cardiac magnetic resonance (CMR) non-enhanced cine sequences in diagnosing HHD and latent cardiac changes caused by hypertension.

METHODS

132 patients who underwent CMR scanning were divided into groups: HHD (42), hypertension with normal cardiac structure and function (HWN) group (46), and normal control (NOR) group (44). Myocardial regions of the end-diastolic (ED) and end-systolic (ES) phases of the CMR short-axis cine sequence images were segmented into regions of interest (ROI). Three feature subsets (ED, ES, and ED combined with ES) were established after radiomic least absolute shrinkage and selection operator feature selection. Nine radiomic models were built using random forest (RF), support vector machine (SVM), and naive Bayes. Model performance was analyzed using receiver operating characteristic curves, and metrics like accuracy, area under the curve (AUC), precision, recall, and specificity.

RESULTS

The feature subsets included first-order, shape, and texture features. SVM of ED combined with ES achieved the highest accuracy (0.833), with a macro-average AUC of 0.941. AUCs for HHD, HWN, and NOR identification were 0.967, 0.876, and 0.963, respectively. Precisions were 0.972, 0.740, and 0.826; recalls were 0.833, 0.804, and 0.863, respectively; and specificities were 0.989, 0.863, and 0.909, respectively.

CONCLUSIONS

Radiomics technology using CMR non-enhanced cine sequences can detect early cardiac changes due to hypertension. It holds promise for future use in screening for latent cardiac damage in early HHD.

Cardiac and Liver Fibrosis Assessed by Multiparametric MRI in Patients with Fontan Circulation

The abnormal hemodynamics in Fontan circulation due to persistently increased systemic venous pressure results in hepatic venous congestion and Fontan-associated liver disease. Combined assessment of cardiac and liver fibrosis and cardiac remodeling using multiparametric MRI in this context have not been fully explored. To evaluate cardiac and liver fibrosis and cardiac remodeling using multiparametric MRI in patients who have undergone Fontan procedures. Thirty-eight patients and 23 controls underwent cardiac and liver MRI examinations in a 3.0-T scanner. Mann-Whitney, Fisher exact test, and Spearman's correlation were applied to evaluate myocardial volumes, function, native cardiac and liver T1 mapping, ECVs and liver stiffness. The mean native cardiac T1 value (p = 0.018), cardiac ECV (p < 0.001), liver native T1 (p < 0.001), liver ECV (p < 0.001), and liver stiffness (p < 0.001) were higher in patients than controls. The indexed end-diastolic volume (EDVi) correlated with the myocardial ECV (r = 0.356; p = 0.033), native liver T1 (r = 0.571; p < 0.001), and with liver stiffness (r = 0.391; p = 0.015). In addition, liver stiffness correlated with liver ECV (r = 0.361; p = 0.031) and native liver T1 (r = 0.458; p = 0.004). An association between cardiac remodeling and cardiac and liver fibrosis were found in this population. The usefulness of MRI to follow cardiac and liver involvement in these patients is critical to improve treatment strategies and to prevent the need for combined liver and heart transplantation.

Three-dimensional assessment of image distortion induced by active cardiac implants in 3.0T CMR

CMR at 3.0T in the presence of active cardiac implants remains a challenge due to susceptibility artifacts. Beyond a signal void that cancels image information, magnetic field inhomogeneities may cause distorted appearances of anatomical structures. Understanding influencing factors and the extent of distortion are a first step towards optimizing the image quality of CMR with active implants at 3.0T. All measurements were obtained at a clinical 3.0T scanner. An in-house designed phantom with a 3D cartesian grid of water filled spheres was used to analyze the distortion caused by four representative active cardiac devices (cardiac loop recorder, pacemaker, 2 ICDs). For imaging a gradient echo (3D-TFE) sequence and a turbo spin echo (2D-TSE) sequence were used. The work defines metrics to quantify the different features of distortion such as changes in size, location and signal intensity. It introduces a specialized segmentation technique based on a reaction-diffusion-equation. The distortion features are dependent on the amount of magnetic material in the active implants and showed a significant increase when measured with the 3D TFE compared to the 2D TSE. This work presents a quantitative approach for the evaluation of image distortion at 3.0T caused by active cardiac implants and serves as foundation for both further optimization of sequences and devices but also for planning of imaging procedures.

Cardiac function in a large animal model of myocardial infarction at 7 T: deep learning based automatic segmentation increases reproducibility

Cardiac magnetic resonance (CMR) imaging allows precise non-invasive quantification of cardiac function. It requires reliable image segmentation for myocardial tissue. Clinically used software usually offers automatic approaches for this step. These are, however, designed for segmentation of human images obtained at clinical field strengths. They reach their limits when applied to preclinical data and ultrahigh field strength (such as CMR of pigs at 7 T). In our study, eleven animals (seven with myocardial infarction) underwent four CMR scans each. Short-axis cine stacks were acquired and used for functional cardiac analysis. End-systolic and end-diastolic images were labelled manually by two observers and inter- and intra-observer variability were assessed. Aiming to make the functional analysis faster and more reproducible, an established deep learning (DL) model for myocardial segmentation in humans was re-trained using our preclinical 7 T data (n = 772 images and labels). We then tested the model on n = 288 images. Excellent agreement in parameters of cardiac function was found between manual and DL segmentation: For ejection fraction (EF) we achieved a Pearson's r of 0.95, an Intraclass correlation coefficient (ICC) of 0.97, and a Coefficient of variability (CoV) of 6.6%. Dice scores were 0.88 for the left ventricle and 0.84 for the myocardium.

Evaluation of the Truncated Cone-Rhomboid Pyramid Formula for Simplified Right Ventricular Quantification: A Cardiac Magnetic Resonance Study

Background/Objective: Cardiac magnetic resonance (CMR) is the reference method for right ventricular (RV) volume and function analysis, but time-consuming manual segmentation and corrections of imperfect automatic segmentations are needed. This study sought to evaluate the applicability of an echocardiographically established truncated cone-rhomboid pyramid formula (CPF) for simplified RV quantification using CMR. Methods: A total of 70 consecutive patients assigned to RV analysis using CMR were included. As standard method, the manual contouring of RV-short axis planes was performed for the measurement of end-diastolic volume (EDV) and end-systolic volume (ESV). Additionally, two linear measurements in four-chamber views were obtained in systole and diastole: basal diameters at the level of tricuspid valve (Dd and Ds) and baso-apical lengths from the center of tricuspid valve to the RV apex (Ld and Ls) were measured for the calculation of RV-EDV = 1.21 × Dd2 × Ld and RV-ESV = 1.21 × Ds 2 × Ls using CPF. Results: RV volumes using CPF were slightly higher than those using standard CMR analysis (RV-EDV index: 86.2 ± 29.4 mL/m2 and RV-ESV index: 51.5 ± 22.5 mL/m2 vs. RV-EDV index: 81.7 ± 24.1 mL/m2 and RV-ESV index: 44.5 ± 23.2 mL/m2) and RV-EF was lower (RV-EF: 41.1 ± 13.5% vs. 48.4 ± 13.7%). Both methods had a strong correlation of RV volumes (ΔRV-EDV index = -4.5 ± 19.0 mL/m2; r = 0.765, p < 0.0001; ΔRV-ESV index = -7.0 ± 14.4 mL/m2; r = 0.801, p < 0.0001). Conclusions: Calculations of RV volumes and function using CPF assuming the geometrical model of a truncated cone-rhomboid pyramid anatomy of RV is feasible, with a strong correlation to measurements using standard CMR analysis, and only two systolic and diastolic linear measurements in four-chamber views are needed.

Comparative analysis of left ventricle function and deformation imaging in short and long axis plane in cardiac magnetic resonance imaging

Background

Advancements in cardiac imaging have revolutionized our understanding of ventricular contraction. While ejection fraction (EF) is still the gold standard parameter to assess left ventricle (LV) function, strain imaging (SI) has provided valuable insights into ventricular mechanics. The lack of an integrative method including SI parameters in a single, validated formula may limit its use. Our aim was to compare different methods for evaluating global circumferential strain (GCS) and their relationship with global longitudinal strain (GLS) and EF in CMR and how the different evaluations fit in the theoretical relationship between EF and global strain.

Methods

Retrospective monocenter study. Inclusion of every patient who underwent a CMR during a 15 months period with various clinical indication (congenital heart defect, myocarditis, cardiomyopathy). A minimum of three LV long-axis planes and a stack of short-axis slices covering the LV using classical steady-state free precession cine sequences. A single assessment of GLS on long axis (LAX) slices and a double assessment of GCS and EF with both short axis (SAX) and LAX slices were made by a single experienced CMR investigator.

Results

GCS-SAX and GCS-LAX were correlated (r = 0.77, P < 0.001) without being interchangeable with a high reproducibility for GCS, GLS and EF. EF calculated from LAX images showed an overestimation compared to EF derived from SAX images of 7%. The correlation between calculated EF and theoretical EF derived from SI was high (r = 0.88 with EF-SAX, 0.95 with EF-LAX).

Data conclusion

This study highlights the need to integrate strain imaging techniques into clinical by incorporating strain parameters into EF calculations, because it gives a deeper understanding of cardiac mechanics.