Delayed enhancement cardiovascular magnetic resonance assessment of non-ischaemic cardiomyopathies

Integrating myocardial CT perfusion with coronary CT angiography improves risk stratification in patients with dialysis-dependent end-stage renal disease

PURPOSE

Risk stratification for incidence of major adverse cardiovascular events (MACE) in patients with dialysis-dependent end-stage renal disease (dd-ESRD) is challenging. Moreover, the usefulness of coronary CT angiography (CCTA) is often limited because of high calcification. This study aimed to investigate the prognostic value of comprehensive cardiac CT in patients with dd-ESRD for predicting MACE.

MATERIALS AND METHODS

This retrospective analysis included 92 patients with dd-ESRD who underwent comprehensive cardiac CT. Obstructive coronary artery disease (CAD) was defined by CCTA with > 50% stenosis. Global myocardial blood flow (MBF) and summed stress score (SSS) were obtained through dynamic CTP. Cox regression analysis was used to assess correlation with MACE. Kaplan-Meier curves were used to estimate cumulative event rates, and the global Chi-square test was used to assess the incremental value of dynamic CTP over CCTA.

RESULTS

During a median follow-up of 2.3 years, 43 patients experienced MACE. Univariate analysis revealed that presence of obstructive CAD, higher SSS, and lower global MBF were significantly associated with increased risk of MACE. In multivariable analysis, lower global MBF and presence of obstructive CAD were independently associated with MACE (p = 0.02, and p = 0.04, respectively). CCTA and dynamic CTP combination had incremental value over CCTA alone for predicting MACE, respectively (global Chi-square score, 19.3 and 11.7, respectively).

CONCLUSION

Presence of obstructive CAD on CCTA and lower global MBF on dynamic CTP are independently associated with increased risk of MACE in patients with dd-ESRD. The addition of dynamic CTP to CCTA may improve risk stratification in this population.

Unipolar Voltage Mapping to Predict Recovery of Left Ventricular Ejection Fraction in Patients With Recent-Onset Nonischemic Cardiomyopathy

BACKGROUND

The ability to predict recovery of left ventricular ejection fraction (LVEF) in response to guideline-directed therapy among patients with nonischemic cardiomyopathy is desired. We sought to determine whether left ventricular endocardial unipolar voltage measured during invasive electroanatomic mapping could be used to predict LVEF recovery among those with recent-onset nonischemic cardiomyopathy.

METHODS

We analyzed the left ventricular voltage maps of patients included in the eMAP trial (Electrogram-Guided Myocardial Advanced Phenotyping; NCT03293381), a prospective, nonrandomized, interventional trial conducted at 2 institutions between 2017 and 2020. Patients had recent-onset nonischemic cardiomyopathy defined by LVEF ≤45% and development of symptoms or signs of heart failure within the past 6 months. Detailed voltage maps of the left ventricular endocardium were generated using the Carto electroanatomic mapping system. Abnormal unipolar amplitude was defined as <8.27 mV. The primary end point was recovery of LVEF (Recovery) defined by a 1-year LVEF ≥50% or ≥45% with ≥10% increase from baseline.

RESULTS

Of the 29 enrolled patients (median age, 49 years [25th percentile, 39; 75th percentile, 59], 8 females [27.6%]), LVEF recovered in 13 (44.8%) by 1-year follow-up. The percentage of total endocardial surface area with unipolar voltage abnormality (AUA) was significantly lower among Recovery patients than No Recovery patients (18.2% [25th percentile, 6.4; 75th percentile, 22.4] versus 80.0% [25th percentile, 29.5; 75th percentile, 90.9]; P=0.004). Percent AUA was associated with lower likelihood of Recovery (odds ratio, 0.64 per 10% increase in AUA; 95% CI, 0.47-0.88; P=0.006). A 28% cutoff value for percent AUA was 92% sensitive and 75% specific with an area under the receiver operating characteristic curve of 0.81 (95% CI, 0.63-0.99; P=0.001) for predicting recovery versus no recovery. The majority of patients (12 of 13; 92.3%) with a percent AUA >28% did not recover.

CONCLUSIONS

Left ventricular unipolar voltage abnormality is a potent predictor of LVEF recovery among patients recently diagnosed with nonischemic cardiomyopathy. Detailed left ventricular unipolar voltage mapping could therefore be used as a valuable prognostic tool in guiding treatment decisions.

Prevalence of cardiac amyloidosis in atrial fibrillation: a CMR study prior to catheter ablation

The frequency of cardiac amyloidosis potentially present in patients with atrial fibrillation (AF) remains unclear. The purpose of this study is to determine the frequency and clinical characteristics of cardiac amyloidosis latent in AF by performing cardiac magnetic resonance imaging (MRI) in patients scheduled for AF ablation. We retrospectively analyzed 193 consecutive patients who underwent CA and cardiac MRI for atrial fibrillation. The primary endpoint of the study was the frequency of histologically confirmed cardiac amyloidosis or suspected cardiac amyloidosis [positive imaging findings on cardiac MRI strongly suspecting cardiac amyloidosis (diffuse subendocardial late gadolinium enhancement or MRI-derived extracellular volume of > 0.40)]. Among the 193 patients, 8 were confirmed or suspected cases of cardiac amyloidosis, representing a frequency of 4% (8/193 patients). Multivariate analysis identified interventricular septal thickness at end-diastole (LVSd) as an independent and significant predictor of cardiac amyloidosis (OR: 1.72, 95% CI 1.12-2.87, p = 0.020).The optimal cut-off value for IVSd was determined to be > 12.9 mm based on the Youden index. At this cut-off, the sensitivity was 75.0% (95% CI 34.9-96.8%) and the specificity was 92.3% (95% CI 87.4-95.7%), allowing for the identification of patients with definite or suspected cardiac amyloidosis. The frequency of confirmed and suspected cases of cardiac amyloidosis among patients with an IVSd > 12.9 mm was 30% (6/20 patients). In addition, prevalence of biopsy-proven cardiac amyloidosis was 10% (2/20). The prevalence of cardiac amyloidosis in atrial fibrillation patients scheduled for ablation with cardiac hypertrophy is not negligible.

Identifying etiologies of heart failure using non-contrast cardiac magnetic resonance imaging: cine imaging, T1 and T2 mapping, and texture analysis for T1 mapping

Objective

The aim of this retrospective study was to evaluate the usefulness of non-contrast cardiac magnetic resonance imaging, including cine imaging, T1 and T2 mapping, and texture analysis for T1 mapping, for identifying etiologies of heart failure (HF).

Methods

Forty-seven patients with HF were examined using a 1.5 T scanner. Cine imaging parameters and native T1 and T2 values at the mid-septal segment were measured. Vertical run length nonuniformity, vertical gray level nonuniformity (vGLNU), wavelet energy LL(3) and HH (4) on T1 mapping were estimated at the mid-septal segment using open-access software. Late gadolinium enhancement was investigated to help diagnose the etiologies of HF. We used Kruscal-Wallis' with a post-hoc Steel-Dwass' test, Wilcoxon signed-ranked test, Pearson's chai square test and receiver operator curve analysis (ROC) to assess the usefulness of non-contrast CMR for identifying etiologies of HF.

Results

There were significant differences in left ventricular end-diastolic volume (LVEDV) indexed to body surface area (LVEDVi), left ventricular myocardial mass/LVEDV, native T1, and vGLNU between dilated cardiomyopathy (DCM), hypertensive cardiomyopathy (HC) and tachycardia-induced cardiomyopathies (TIC). DCM had higher T1 and lower vGLNU than HC. When compared with TIC, DCM showed significantly higher LVEDV and LVEDVi. ROC analysis revealed that LVEDV and vGLNU provided high specificity for differentiating DCM from the other etiologies.

Conclusion

Native T1 mapping and its texture analysis may be valuable for differentiating between DCM and HC. Cine imaging can be useful for differentiating between DCM and TIC.

A Machine Learning Model Using Cardiac CT and MRI Data Predicts Cardiovascular Events in Obstructive Coronary Artery Disease

Background Multimodality imaging is essential for personalized prognostic stratification in suspected coronary artery disease (CAD). Machine learning (ML) methods can help address this complexity by incorporating a broader spectrum of variables. Purpose To investigate the performance of an ML model that uses both stress cardiac MRI and coronary CT angiography (CCTA) data to predict major adverse cardiovascular events (MACE) in patients with newly diagnosed CAD. Materials and Methods This retrospective study included consecutive symptomatic patients without known CAD referred for CCTA between December 2008 and January 2020. Patients with obstructive CAD (at least one ≥50% stenosis at CCTA) underwent stress cardiac MRI for functional assessment. Eighteen clinical, two electrocardiogram, nine CCTA, and 12 cardiac MRI parameters were evaluated as inputs for the ML model, which involved automated feature selection with the least absolute shrinkage and selection operator algorithm and model building with an XGBoost algorithm. The primary outcome was MACE, defined as a composite of cardiovascular death and nonfatal myocardial infarction. External testing was performed using two independent datasets. Performance was compared between the ML model and existing scores and other approaches using the area under the receiver operating characteristic curve (AUC). Results Of 2210 patients who completed cardiac MRI, 2038 (mean age, 70 years ± 12 [SD]; 1091 [53.5%] female participants) completed follow-up (median duration, 7 years [IQR, 6-9 years]); 281 experienced MACE (13.8%). The ML model exhibited a higher AUC (0.86) for MACE prediction than the European Society of Cardiology score (0.55), QRISK3 score (0.60), Framingham Risk Score (0.50), segment involvement score (0.71), CCTA data alone (0.76), or stress cardiac MRI data alone (0.83) (P value range, <.001 to .004). The ML model also exhibited good performance in the two external validation datasets (AUC, 0.84 and 0.92). Conclusion An ML model including both CCTA and stress cardiac MRI data demonstrated better performance in predicting MACE than traditional methods and existing scores in patients with newly diagnosed CAD. © RSNA, 2025 Supplemental material is available for this article.

Utilization of Cardiac Magnetic Resonance Imaging for Assessing Myocardial Fibrosis in Prognosis Evaluation and Risk Stratification of Patients with Dilated Cardiomyopathy

Dilated cardiomyopathy (DCM) is the ultimate manifestation of the myocardial response to various genetic and environmental changes and is characterized mainly by impaired left ventricular systolic and diastolic function. DCM can ultimately lead to heart failure, ventricular arrhythmia (VA), and sudden cardiac death (SCD), making it a primary indication for heart transplantation. With advancements in modern medicine, several novel techniques for evaluating myocardial involvement and disease severity from diverse perspectives have been developed. Myocardial fibrosis is a significant contributor to VA events and SCD. Based on different pathological mechanisms, myocardial fibrosis can be categorized into replacement and interstitial forms. Late gadolinium enhancement (LGE) derived from cardiovascular magnetic resonance is the clinical gold standard for evaluating replacement myocardial fibrosis and exhibits high concordance with histological replacement fibrosis. However, because of the absence of normal tissue as a control, the LGE technique often fails to effectively visualize diffuse interstitial fibrosis. In such cases, T1 mapping and extracellular volume fraction mapping can be complementary or alternative methods to the LGE technique for detecting interstitial fibrosis. This review aimed to provide a comprehensive and precise assessment of myocardial fibrosis and to determine the use of cardiac magnetic resonance imaging for prognostic evaluation and risk stratification of patients with DCM.

Cardiovascular magnetic resonance in β-thalassemia major: beyond T2

Β-thalassemia major (TM) patients underwent regular transfusions to prevent complications of chronic anemia. However, these regular transfusions result in progressive iron accumulation in vital organs, including the heart. Myocardial iron overload can lead to cardiac dysfunction and ultimately to heart failure. Diagnosis of cardiac dysfunction in β-TM patients is usually made through clinical examination, electrocardiogram, and echocardiography. Cardiac magnetic resonance (CMR), through the measurement of T2* relaxation time, represents the diagnostic modality of choice for assessing myocardial iron overload and guiding the iron chelation therapy. Despite a tailored chelation therapy reducing myocardial iron overload, heart failure remains the leading cause of morbidity and mortality even in well-treated β-TM patients. Advances in CMR, including myocardial strain, parametric mapping (T1, T2, and extracellular volume), and late gadolinium enhancement (LGE) measurements, have expanded its role in the diagnosis, prognosis, and follow-up of these patients. This review seeks to offer a thorough overview of the potential uses of CMR in β-TM, extending beyond the established role of T2* measurement in guiding chelation therapy. It delves into the emerging applications of new CMR imaging biomarkers that could improve the overall management of β-TM patients.

Assessing coronary artery stenosis exacerbated impact on left ventricular function and deformation in metabolic syndrome patients by 3.0 T cardiac magnetic resonance imaging

BACKGROUND

Metabolic syndrome (MetS) and coronary artery stenosis (CAS) independently increase the risk of cardiovascular events, while the impact of CAS on left ventricular (LV) function and deformation in MetS patients remains unclear. This study investigates how varying degrees of CAS exacerbate LV function and myocardial deformation in MetS patients.

METHODS

One hundred thirty-one MetS patients who underwent CMR examinations were divided into two groups: the MetS(CAS-) group (n = 47) and the MetS(CAS+) group (n = 84). The MetS(CAS+) group was divided into MetS with non-obstructive CAS(NOCAS+) (n = 30) and MetS with obstructive CAS(OCAS+) group (n = 54). Additionally, 48 age- and sex-matched subjects were included as a control group. LV functional and deformation parameters were measured and compared among subgroups. The determinants of decreased LV global peak strains in all MetS patients were identified using linear regression. The receiver operating characteristic (ROC) curve and logistic regression model (LRM) evaluated the diagnostic accuracy of the degree of CAS for identifying impaired LV strain.

RESULTS

Compared to MetS(CAS-), MetS(NOCAS+) showed a significantly increased LV mass index (p < 0.05). Global longitudinal peak strain was decreased gradually from MetS(CAS-) through MetS(NOCAS+) to MetS(OCAS+) (- 13.02 ± 2.32% vs. - 10.34 ± 4.05% vs. - 7.55 ± 4.48%, p < 0.05). MetS(OCAS+) groups showed significantly decreased LV global peak strain (GPS), PSSR and PDSR in radial and circumferential directions compared with MetS(NOCAS+) (all p < 0.05). The degree of CAS was independently associated with impaired global radial peak strain (GRPS) (β =  - 0.289, p < 0.001) and global longitudinal peak strain (GLPS) (β = 0.254, p = 0.004) in MetS patients. The ROC analysis showed that the degree of CAS can predict impaired GRPS (AUC = 0.730) and impaired GLPS (AUC = 0.685).

CONCLUSION

Besides traditional biochemical indicators, incorporating CAS assessment and CMR assessment of the LV into routine evaluations ensures a more holistic approach to managing MetS patients. Timely intervention of CAS is crucial for improving cardiovascular outcomes in this high-risk population.

Relevance of increased negative T waves in apical hypertrophic cardiomyopathy with progressive myocardial damage: Insights from repeat cardiac magnetic resonance studies

In patients with apical hypertrophic cardiomyopathy (HCM), progressive electrocardiographic changes are observed during long-term follow-up. However, it is difficult to correspond these changes to the specific myocardial changes. Cardiac magnetic resonance (CMR) imaging can elucidate myocardial changes by late gadolinium enhancement. Here, we present the long-term follow-up (>18 years) on a patient with apical HCM, whereupon, precise and continuous changes in the myocardium, causing ST segment and T wave changes on electrocardiography, were observed on CMR images. The combination of electrocardiography and CMR facilitates management of patients with apical HCM because it helps explain and understand the nature of electrocardiography changes over time.

Photon-counting detector computed tomography in cardiac imaging

Photon-counting detector computed tomography (PCD-CT) has emerged as a revolutionary technology in CT imaging. PCD-CT offers significant advancements over conventional energy-integrating detector CT, including increased spatial resolution, artefact reduction and inherent spectral imaging capabilities. In cardiac imaging, PCD-CT can offer a more accurate assessment of coronary artery disease, plaque characterisation and the in-stent lumen. Additionally, it might improve the visualisation of myocardial fibrosis through qualitative late enhancement imaging and quantitative extracellular volume measurements. The use of PCD-CT in cardiac imaging holds significant potential, positioning itself as a valuable modality that could serve as a one-stop-shop by integrating both angiography and tissue characterisation into a single examination. Despite its potential, large-scale clinical trials, standardisation of protocols and cost-effectiveness considerations are required for its broader integration into clinical practice. This narrative review provides an overview of the current literature on PCD-CT regarding the possibilities and limitations of cardiac imaging.

Revealing the unrevealed: echocardiography for non-ischemic scar tissue detection

The detection of myocardial scar tissue profoundly influences athletes care and prognostic categorization. Athletes appear to be at risk of developing fatal arrhythmias when harboring a quiescent cardiac disorder. Early identification of disease in asymptomatic individuals through preparticipation screening is means to prevent these events. We presented a male marathon runner master athlete who came at our Department of Sports Medicine for a preparticipation screening. Baseline 12-lead standard electrocardiogram was normal. A maximal cycle ergometer exercise test revealed exercise-induced premature ventricular contractions (PVCs) with uncommon morphology. Echocardiography revealed an hyperechogenic zone at mid-basal posterior segments of the left ventricle. Twenty-four-hours ECG Holter monitoring, with training session, showed some isolated polymorphic PVCs even during training session. Cardiac magnetic resonance (CMR) confirmed the presence of a non-ischemic left ventricular scar (subepicardial) into the mid-basal segment of the posterior wall. Echocardiography is a first-line, economic, and accessible diagnostic test for athletes and it can be useful, when abnormalities are detected, to indicate further investigations, such as CMR. Although non-ischemic left ventricular scarring is difficult to detect on echocardiography, this event is sometimes possible and require further investigation when observed.

Cardiac sarcoidosis: diagnosis and management

Non-caseating granulomatous infiltration of the myocardium is the hallmark of cardiac sarcoidosis (CS). CS manifests clinically as conduction disturbance, ventricular arrhythmia, sudden cardiac death and/or heart failure with reduced ejection fraction. Other than confirmation through endomyocardial biopsy, a diagnosis of probable CS can be established by histological evidence of systemic sarcoidosis in addition to characteristic clinical or advanced imaging findings. Cardiac Magnetic Resonance imaging (CMR) and 18F-flurodeoxyglycose positron emission tomography (FDG-PET) are imaging modalities indispensable in the diagnosis and monitoring of CS. FDG-PET is the method of choice for identifying the active inflammatory phase of CS and in the monitoring and modifying of immunosuppressive treatment. CMR is better suited for assessing cardiac morphology and function. Both modalities are more effective in detecting CS when used in combination than either is alone. Management of CS is primarily based upon observational data of low quality due to a paucity of randomized controlled trials. Corticosteroid therapy and/or tiered-immunosuppression are the mainstays of treatment in reducing myocardial inflammation. Steroid-sparing agents aim to limit the unfavorable side-effects of a significant steroid burden. Antiarrhythmics and guideline-directed medical therapies are utilized for control of ventricular arrhythmia and left ventricular dysfunction respectively. CS necessitates multidisciplinary care in specialized centers to most effectively diagnose and manage the disease. Additional randomized trials are warranted to further our understanding of medical optimization in CS.

Artificial intelligence-based fully automated stress left ventricular ejection fraction as a prognostic marker in patients undergoing stress cardiovascular magnetic resonance

AIMS

This study aimed to determine in patients undergoing stress cardiovascular magnetic resonance (CMR) whether fully automated stress artificial intelligence (AI)-based left ventricular ejection fraction (LVEFAI) can provide incremental prognostic value to predict death above traditional prognosticators.

METHODS AND RESULTS

Between 2016 and 2018, we conducted a longitudinal study that included all consecutive patients referred for vasodilator stress CMR. LVEFAI was assessed using AI algorithm combines multiple deep learning networks for LV segmentation. The primary outcome was all-cause death assessed using the French National Registry of Death. Cox regression was used to evaluate the association of stress LVEFAI with death after adjustment for traditional risk factors and CMR findings. In 9712 patients (66 ± 15 years, 67% men), there was an excellent correlation between stress LVEFAI and LVEF measured by expert (LVEFexpert) (r = 0.94, P < 0.001). Stress LVEFAI was associated with death [median (interquartile range) follow-up 4.5 (3.7-5.2) years] before and after adjustment for risk factors [adjusted hazard ratio, 0.84 (95% confidence interval, 0.82-0.87) per 5% increment, P < 0.001]. Stress LVEFAI had similar significant association with death occurrence compared with LVEFexpert. After adjustment, stress LVEFAI value showed the greatest improvement in model discrimination and reclassification over and above traditional risk factors and stress CMR findings (C-statistic improvement: 0.11; net reclassification improvement = 0.250; integrative discrimination index = 0.049, all P < 0.001; likelihood-ratio test P < 0.001), with an incremental prognostic value over LVEFAI determined at rest.

CONCLUSION

AI-based fully automated LVEF measured at stress is independently associated with the occurrence of death in patients undergoing stress CMR, with an additional prognostic value above traditional risk factors, inducible ischaemia and late gadolinium enhancement.

The Importance of Cardiac Magnetic Resonance in the Assessment Risk of Cardiac Arrhythmias in Patients with Arterial Hypertension

Objectives: Arterial hypertension (AH) is one of the major risk factors for cardiovascular diseases. An association between untreated AH and arrhythmia is observed. Cardiac magnetic resonance (CMR) assesses myocardial fibrosis by detecting foci of late gadolinium enhancement (LGE). Clinical significance of LGE at the right ventricular insertion point (RVIP) is not fully established. This study aimed to assess the relationship between the presence of LGE at the RVIP determined by CMR and the incidence of arrhythmia in a group suffering from arterial hypertension. Methods: The study group consisted of 81 patients with AH (37 men and 44 women, age: 56.7 ± 7.1 years). All subjects underwent CMR and 24 h Holter ECG monitoring. Two subgroups were distinguished in the study group based on the criterion of the presence of LGE at the RVIP in CMR. The RVIP+ subgroup consisted of patients with LGE at the RVIP, while the RVIP- group consisted of patients without LGE at the RVIP. Results: The RVIP+ subgroup was characterized by higher maximum and minimum heart rates in 24 h Holter ECG recordings compared to the RVIP- subgroup (p < 0.05). The RVIP+ subgroup had a statistically significantly higher number of single premature supraventricular beats, supraventricular tachycardias, and single premature ventricular beats than the RVIP- subgroup (p < 0.05). Regression analysis documented that a longer duration of AH (counted from diagnosis) as well as the occurrence of LGE at the RVIP (assessed by CMR) are independent risk factors for arrhythmia (p < 0.05). Conclusions: Due to the possibility of detecting LGE at the RVIP, CMR may be a useful diagnostic method in estimating the risk of arrhythmias in the group of patients with AH.

Advanced myocardial characterization and function with cardiac CT

Non-invasive imaging with characterization and quantification of the myocardium with computed tomography (CT) became feasible owing to recent technical developments in CT technology. Cardiac CT can serve as an alternative modality when cardiac magnetic resonance imaging and/or echocardiography are contraindicated, not feasible, inconclusive, or non-diagnostic. This review summarizes the current and potential future role of cardiac CT for myocardial characterization including a summary of late enhancement techniques, extracellular volume quantification, and strain analysis. In addition, this review highlights potential fields for research about myocardial characterization with CT to possibly include it in clinical routine in the future.

Cardiac sarcoidosis in patients with recurrent ventricular arrhythmias refractory to endocardial ablation

INTRODUCTION

The clinical presentation of cardiac sarcoidosis is diverse. Detection of granuloma in histopathological evaluation proves the diagnosis, but endomyocardial biopsy (EMB) is associated with a high sampling error. However, prompt immunosuppressive therapy may significantly affect patient's prognosis. By analyzing our single center cohort of patients with recurrent ventricular arrhythmias (VA) and nonischemic cardiomyopathy after failure of endocardial ablation, we looked for additional markers supporting the diagnosis of cardiac sarcoidosis.

METHOD

In the last 4 years, 135 patients (mean age 49 y, 63% male) were hospitalized for epicardial ventricular arrhythmia (VA) ablation after failure of endocardial ablation. Nineteen patients had either previously received a diagnosis of cardiac sarcoidosis or were newly diagnosed. The mean follow-up time was 4.3 years. The ECG criteria, primary manifestation, histological findings in EMB, history of VT ablation, distribution of scars on MRI, electroanatomical mapping (EAM), PET CT findings, presence of atrial tachycardias, valve disease and comorbidities were analyzed.

RESULTS

Six of 19 (32%) patients showed right bundle block; 6 of 19 (32%) had AV nodal disease, including 4 patients with AV-block III; and 14 patients (73%) primarily presented with ventricular arrhythmias (including 3 with cardiac arrest). In all 19 patients cardiac EMB revealed elevated CD68 macrophages and CD3 T lymphocytes, and 7 of 19 were positive for granuloma (36,8%). Six of 6 patients (100%) undergoing PET CT showed acute inflammation. By analyzing the scar distribution, the most common locations were basal anteroseptal, basal inferoseptal, mid inferoseptal, mid inferior and the septal RV/RVOT. (septal substrate in 100%). There was a high correlation between the findings on the MRIs and low voltage in the electroanatomical mapping EAM). All patients received an immunosuppressive therapy. No patient died during follow-up, 1 patient had a high urgent heart transplant after withdrawal of steroid therapy.

CONCLUSION

Chronic untreated inflammation may be the underlying pathophysiology for patients with unspecific cardiomyopathy and recurrent VA refractory to endocardial and epicardial ablation. Septal substrate in the EAM/MRI, elevated CD3 lymphocytes in the EBM and inflammation in the PET CT may indicate the possible diagnosis of cardiac sarcoidosis. Initializing immunosuppressive therapy in patients with this dedicated constellation with should be taken into consideration.

Conditions for late gadolinium enhancement MRI in myocardial infarction model rats that better reflect microscopic tissue staining

Late gadolinium enhancement (LGE) is a widely used magnetic resonance imaging method for assessing cardiac disease. However, the relationship between different LGE signal thresholds and microscopic tissue staining images is unclear. In this study, we performed cardiovascular MRI on myocardial infarction (MI) model rats and evaluated the relationship between LGE with different signal thresholding methods and tissue staining images. We prepared 16 rats that underwent MRI 14-18 days following a surgery to create an MI model. We captured cine and LGE images of the cardiac short-axis and longitudinal two- and four-chamber views. The mean ± 2SD, ± 3SD, and ± 5SD of the pixel values in the non-infarcted area were defined as the LGE area. We compared areas of Sirius red staining, determined by the color tone, with their respective LGE areas at end-diastole and end-systole. We observed that the LGE area calculated as the mean ± 2SD of the non-infarcted area at end-diastole demonstrated a significant positive correlation with the area of Sirius red staining (Pearson's correlation coefficient in both: 0.81 [p < 0.01]). Therefore, the LGE area calculated as the mean ± 2SD of the non-infarcted area at end-diastole best reflected the MI area in tissue staining.

MRI of cardiac involvement in COVID-19

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has led to a diverse pattern of myocardial injuries, including myocarditis, which is linked to adverse outcomes in patients. Research indicates that myocardial injury is associated with higher mortality in hospitalized severe COVID-19 patients (75.8% vs 9.7%). Cardiovascular Magnetic Resonance (CMR) has emerged as a crucial tool in diagnosing both ischaemic and non-ischaemic myocardial injuries, providing detailed insights into the impact of COVID-19 on myocardial tissue and function. This review synthesizes existing studies on the histopathological findings and CMR imaging patterns of myocardial injuries in COVID-19 patients. CMR imaging has revealed a complex pattern of cardiac damage in these patients, including myocardial inflammation, oedema, fibrosis, and ischaemic injury, due to coronary microthrombi. This review also highlights the role of LLC criteria in diagnosis of COVID-related myocarditis and the importance of CMR in detecting cardiac complications of COVID-19 in specific groups, such as children, manifesting multisystem inflammatory syndrome in children (MIS-C) and athletes, as well as myocardial injuries post-COVID-19 infection or following COVID-19 vaccination. By summarizing existing studies on CMR in COVID-19 patients and highlighting ongoing research, this review contributes to a deeper understanding of the cardiac impacts of COVID-19. It emphasizes the effectiveness of CMR in assessing a broad spectrum of myocardial injuries, thereby enhancing the management and prognosis of patients with COVID-19 related cardiac complications.

MI and Non-obstructive Coronary Arteries

MI and non-obstructive coronary arteries (MINOCA) is recognized as an important contributor to adverse cardiovascular outcomes in both men and women but is particularly prevalent in young women. Multiple coronary mechanisms such as coronary plaque disruption, coronary artery spasm, coronary microvascular dysfunction, spontaneous coronary artery dissection, and coronary thromboembolism can trigger MINOCA. Beyond routine left heart catheterization, invasive intracoronary imaging and cardiac MRI can help to clarify the cause of MINOCA. Conditions such as myocarditis, takotsubo syndrome, and cardiomyopathy are on the differential as alternate explanations in those suspected of MINOCA. Identification of the underlying cause in a case of MINOCA has therapeutic implications. While long-term management of MINOCA is not standardized, angiotensin converting enzyme inhibitors and statins appear to be of benefit. In this review, we discuss the prevalence and pathophysiology of MINOCA, diagnostic considerations, and current treatment approaches to manage this high-risk group of patients.

Timing of cardiac magnetic resonance and diagnostic yield in patients with myocardial infarction with nonobstructive coronary arteries

INTRODUCTION AND OBJECTIVES

The present study sought to establish the diagnostic yield of cardiovascular magnetic resonance (CMR) in a large cohort of patients admitted with myocardial infarction (MI) with nonobstructive coronary artery disease (MINOCA) based on the timing of referral to CMR.

METHODS

Consecutive patients referred to CMR from January 2009 to February 2022 with a working diagnosis of MINOCA were retrospectively evaluated. Cine, T2-weighted, early, and late gadolinium-enhanced images were acquired and analyzed. The frequency of the underlying diagnosis and the association between timing of CMR and relative frequency of each diagnosis were assessed.

RESULTS

We included 207 patients (median age 50 years, 60% men). Final diagnosis after CMR was achieved in 91% of the patients (myocarditis in 45%, MI in 20%, tako-tsubo cardiomyopathy in 19%, and other cardiomyopathies in 7%). The performance of CMR within 7 days of admission with MINOCA (median, 5 days; 117 patients) allowed a higher diagnostic yield compared with CMR performed later (median, 10 days; 88 patients) (96% vs 86%, P=.02). Although myocarditis was the most frequent diagnosis in both groups according to time to CMR, its frequency was higher among patients with a CMR performed within the first 7 days (53% vs 35%, P=.02). The frequency of other underlying diagnoses was not influenced by CMR timing.

CONCLUSIONS

CMR led to an underlying diagnosis of MINOCA in 91% of patients and its diagnostic yield increased to 96% when CMR was performed within 7 days of admission. The most frequent diagnosis was myocarditis..

The additive prognostic value of end-systolic pressure-volume relation by stress CMR in patients with known or suspected coronary artery disease

PURPOSE

The difference between rest and peak stress end-systolic pressure-volume relation (ΔESPVR) is an afterload-independent index of left ventricular (LV) contractility. We assessed the independent prognostic value of ΔESPVR index by dipyridamole stress-cardiovascular magnetic resonance (CMR) in patients with known/suspected coronary artery disease (CAD).

METHODS

We considered 196 consecutive patients (62.74 ± 10.66 years, 49 females). Wall motion and perfusion abnormalities at rest and peak stress were analysed. Replacement myocardial fibrosis was detected by late gadolinium enhancement (LGE) technique. The ESPVR was evaluated at rest and peak stress from raw measurement of systolic arterial pressure and end-systolic volume by biplane Simpson's method.

RESULTS

A reduced ΔESPVR index (≤ 0.02 mmHg/mL/m2) was found in 88 (44.9%) patients and it was associated with a lower LV ejection fraction (EF) and with a higher frequency of abnormal stress CMR and myocardial fibrosis. During a mean follow-up of 53.17 ± 28.21 months, 50 (25.5%) cardiac events were recorded: 5 cardiac deaths, 17 revascularizations, one myocardial infarction, 23 hospitalisations for heart failure or unstable angina, and 4 ventricular arrhythmias. According to Cox regression analysis, diabetes, family history, LVEF, abnormal stress CMR, myocardial fibrosis, and reduced ΔESPVR were significant univariate prognosticators. In the multivariate analysis the independent predictors were ΔESPVR index ≤ 0.02 mmHg/mL/m2 (hazard ratio-HR = 2.58, P = 0.007), myocardial fibrosis (HR = 2.13, P = 0.036), and diabetes (HR = 2.33, P = 0.012).

CONCLUSION

ΔESPVR index by stress-CMR was independently associated with cardiac outcomes in patients with known/suspected CAD, in addition to replacement myocardial fibrosis and diabetes. Thus, the assessment of ΔESPVR index may be included into the standard stress-CMR exam to further stratify the patients.

Nonischemic or Dual Cardiomyopathy in Patients With Coronary Artery Disease

BACKGROUND

Randomized trials in obstructive coronary artery disease (CAD) have largely shown no prognostic benefit from coronary revascularization. Although there are several potential reasons for the lack of benefit, an underexplored possible reason is the presence of coincidental nonischemic cardiomyopathy (NICM). We investigated the prevalence and prognostic significance of NICM in patients with CAD (CAD-NICM).

METHODS

We conducted a registry study of consecutive patients with obstructive CAD on coronary angiography who underwent contrast-enhanced cardiovascular magnetic resonance imaging for the assessment of ventricular function and scar at 4 hospitals from 2004 to 2020. We identified the presence and cause of cardiomyopathy using cardiovascular magnetic resonance imaging and coronary angiography data, blinded to clinical outcomes. The primary outcome was a composite of all-cause death or heart failure hospitalization, and secondary outcomes were all-cause death, heart failure hospitalization, and cardiovascular death.

RESULTS

Among 3023 patients (median age, 66 years; 76% men), 18.2% had no cardiomyopathy, 64.8% had ischemic cardiomyopathy (CAD+ICM), 9.3% had CAD+NICM, and 7.7% had dual cardiomyopathy (CAD+dualCM), defined as both ICM and NICM. Thus, 16.9% had CAD+NICM or dualCM. During a median follow-up of 4.8 years (interquartile range, 2.9, 7.6), 1116 patients experienced the primary outcome. In Cox multivariable analysis, CAD+NICM or dualCM was independently associated with a higher risk of the primary outcome compared with CAD+ICM (adjusted hazard ratio, 1.23 [95% CI, 1.06-1.43]; P=0.007) after adjustment for potential confounders. The risks of the secondary outcomes of all-cause death and heart failure hospitalization were also higher with CAD+NICM or dualCM (hazard ratio, 1.21 [95% CI, 1.02-1.43]; P=0.032; and hazard ratio, 1.37 [95% CI, 1.11-1.69]; P=0.003, respectively), whereas the risk of cardiovascular death did not differ from that of CAD+ICM (hazard ratio, 1.15 [95% CI, 0.89-1.48]; P=0.28).

CONCLUSIONS

In patients with CAD referred for clinical cardiovascular magnetic resonance imaging, NICM or dualCM was identified in 1 of every 6 patients and was associated with worse long-term outcomes compared with ICM. In patients with obstructive CAD, coincidental NICM or dualCM may contribute to the lack of prognostic benefit from coronary revascularization.

Role of cardiac magnetic resonance imaging in identifying infarct related artery and non-ischemic pathogenesis in patients presenting with non ST elevation myocardial infarction

INTRODUCTION

Identifying an Infarct-related artery (IRA)in Non-STEMI is sometimes tricky. Besides, myocardial infarction with non-obstructive coronary arteries (MINOCA) mimickers are often labeled as myocardial infarction. Late Gadolinium enhancement (LGE) on cardiac MRI can help in identifying IRA besides MINOCA mimickers.

AIMS

To study the role of LGE on cardiac MRI(CMR) in NSTEMI.

MATERIAL METHODS

It was a prospective observational, double-blinded study. 70 NSTEMI patients were prospectively enrolled over two years. CMR was done before coronary angiography (CAG) during the index hospitalization. Matching was done between IRA selected by CAG and IRA as determined by LGE on MRI.

RESULTS

Mean age was 58 ± 15 years. CAG could not identify IRA in 38.6% (n = 27) patients. In this patient group, LGE-CMR identified IRA in 48.1% (n = 13) & a new non-CAD diagnosis was identified in 18.5% (n = 5) patients. IRA was identified in 61.4% (n = 43) by CAG & in this patient group, LGE-CMR identified a different IRA in 6.9% (n = 3) patients. LGE-CMR also identified a new non-CAD diagnosis in 11.6% (n = 5) of patients from this group. Overall, LGE-CMR led to a new IRA diagnosis in 23% (n = 16) patients & a diagnosis of non-ischemic pathogenesis in 14% (n = 10) patients. Non-Ischemic diagnosis on CMR included stress cardiomyopathy in 3, myocarditis in 6, and infiltrative disorder in 1 patient.

CONCLUSION

CMR leads to new IRA diagnoses or non-ischemic pathogenesis in one-third of the cohort.

Chronic kidney disease associated cardiomyopathy: recent advances and future perspectives

PURPOSE OF REVIEW

Cardiomyopathy in chronic kidney disease (CKD) is a complex condition with multiple triggers and poor prognosis. This review provides an overview of recent advances in CKD-associated cardiomyopathy, with a focus on pathophysiology, newly discovered biomarkers and potential therapeutic targets.

RECENT FINDINGS

CKD is associated with a specific pattern of myocardial hypertrophy and fibrosis, resulting in diastolic and systolic dysfunction, and often triggered by nonatherosclerotic processes. Novel biomarkers, including amino-terminal type III procollagen peptide (PIIINP), carboxy-terminal type I procollagen peptide (PICP), FGF23, marinobufagenin, and several miRNAs, show promise for early detection and risk stratification. Treatment options for CKD-associated cardiomyopathy are limited. Sodium glucose cotransporter-2 inhibitors have been shown to reduce left ventricle hypertrophy and improve ejection fraction in individuals with diabetes and mild CKD, and are currently under investigation for more advanced stages of CKD. In hemodialysis patients calcimimetic etelcalcetide resulted in a significant reduction in left ventricular mass.

SUMMARY

CKD-associated cardiomyopathy is a common and severe complication in CKD. The identification of novel biomarkers may lead to future therapeutic targets. Randomized clinical trials in individuals with more advanced CKD would be well posed to expand treatment options for this debilitating condition.

Unrecognized myocardial scar by late-gadolinium-enhancement cardiovascular magnetic resonance: Insights from the population-based Hamburg City Health Study

BACKGROUND

The presence of myocardial scar is associated with poor prognosis in several underlying diseases. Late-gadolinium-enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging reveals clinically silent "unrecognized myocardial scar" (UMS), but the etiology of UMS often remains unclear. This population-based CMR study evaluated prevalence, localization, patterns, and risk factors of UMS.

METHODS

The study population consisted of 1064 consecutive Hamburg City Health Study participants without a history of coronary heart disease or myocarditis. UMS was assessed by standard-phase-sensitive-inversion-recovery LGE CMR.

RESULTS

Median age was 66 [quartiles 59, 71] years and 37% (388/1064) were females. UMS was detected in 244 (23%) participants. Twenty-five participants (10%) had ischemic, and 217 participants (89%) had non-ischemic scar patterns, predominantly involving the basal inferolateral left-ventricular (LV) myocardium (75%). Two participants (1%) had coincident ischemic and non-ischemic scar. The presence of any UMS was independently associated with LV ejection fraction (odds ratios (OR) per standard deviation (SD) 0.77 (confidence interval (CI) 0.65-0.90), p = 0.002) and LV mass (OR per SD 1.54 (CI 1.31-1.82), p < 0.001). Ischemic UMS was independently associated with LV ejection fraction (OR per SD 0.58 (CI 0.39-0.86), p = 0.007), LV mass (OR per SD 1.74 (CI 1.25-2.45), p = 0.001), and diabetes (OR 4.91 (CI 1.66-13.03), p = 0.002). Non-ischemic UMS was only independently associated with LV mass (OR per SD 1.44 (CI 1.24-1.69), p < 0.001).

CONCLUSION

UMS, in particular with a non-ischemic pattern, is frequent in individuals without known cardiac disease and predominantly involves the basal inferolateral LV myocardium. Presence of UMS is independently associated with a lower LVEF, a higher LV mass, and a history of diabetes.

Comparison of left ventricular deformation abnormalities by echocardiography with cardiac magnetic resonance imaging in patients with acute myocarditis and preserved left ventricular ejection fraction

Purpose

Cardiac magnetic resonance imaging (cMRI) represents the gold standard to detect myocarditis. Left ventricular (LV) deformation imaging provides additional diagnostic options presumably exceeding conventional transthoracic echocardiography (TTE). The present study aimed to analyze the feasibility to detect myocarditis in patients (pts) with preserved LV ejection fraction (LVEF) by TTE compared to cMRI. It has been hypothesized that the number of pathological findings by deformation imaging correspond to findings in cMRI.

Methods and results

Between January 2018 and February 2020 102 pts with acute myocarditis according to the modified Lake Louise criteria and early gadolinium enhancement (EGE) by cMRI were identified at the department of cardiology at the University Hospital Leipzig. Twenty-six pts were included in this retrospective comparative study based on specific selection criteria. Twelve pts with normal cMRI served as a control group. LV deformation was analyzed by global and regional longitudinal strain (GLS, rLS), global and regional circumferential and radial strain (GCS, rCS, GRS, rRS), and LV rotation (including layer strain analysis). All parameters were compared to findings of edema, inflammation, and fibrosis by cMRI according to Lake Louise criteria. All pts with acute myocarditis diagnosed by cMRI showed pathological findings in TTE. Especially rCS and LV rotation analyzed by regional layer strain exhibit a high concordance with pathological findings in cMRI. In controls no LV deformation abnormalities were documented. Mean values of GLS, GRS, and GCS were not significantly different between pts with acute myocarditis and controls.

Conclusion

This retrospective analysis documents the feasibility of detecting regional deformation abnormalities by echocardiography in patients with acute myocarditis confirmed by cMRI. The detection of pathological findings due to myocarditis requires the determination of regional deformation parameters, particularly rCS and LV rotation. The assessment of global strain values does not appear to be of critical value.

Myocardial late enhancement and extracellular volume with single-energy, dual-energy, and photon-counting computed tomography

Computed tomography late enhancement (CT-LE) is emerging as a non-invasive technique for cardiac diagnosis with wider accessibility compared to MRI, despite its typically lower contrast-to-noise ratio. Optimizing CT-LE image quality necessitates a thorough methodology addressing contrast administration, timing, and radiation dose, alongside a robust understanding of extracellular volume (ECV) quantification methods. This review summarizes CT-LE protocols, clinical utility, and advances in ECV measurement through both single-energy and dual-energy CT. It also highlights photon-counting detector CT technology as an innovative means to potentially improve image quality and reduce radiation exposure.

Automated inversion time selection for black-blood late gadolinium enhancement cardiac imaging in clinical practice

OBJECTIVE

To simplify black-blood late gadolinium enhancement (BL-LGE) cardiac imaging in clinical practice using an image-based algorithm for automated inversion time (TI) selection.

MATERIALS AND METHODS

The algorithm selects from BL-LGE TI scout images, the TI corresponding to the image with the highest number of sub-threshold pixels within a region of interest (ROI) encompassing the blood-pool and myocardium. The threshold value corresponds to the most recurrent pixel intensity of all scout images within the ROI. ROI dimensions were optimized in 40 patients' scans. The algorithm was validated retrospectively (80 patients) versus two experts and tested prospectively (5 patients) on a 1.5 T clinical scanner.

RESULTS

Automated TI selection took ~ 40 ms per dataset (manual: ~ 17 s). Fleiss' kappa coefficient for automated-manual, intra-observer and inter-observer agreements were [Formula: see text]= 0.73, [Formula: see text] = 0.70 and [Formula: see text] = 0.63, respectively. The agreement between the algorithm and any expert was better than the agreement between the two experts or between two selections of one expert.

DISCUSSION

Thanks to its good performance and simplicity of implementation, the proposed algorithm is a good candidate for automated BL-LGE imaging in clinical practice.

Phenotypic Clustering of Beta-Thalassemia Intermedia Patients Using Cardiovascular Magnetic Resonance

We employed an unsupervised clustering method that integrated demographic, clinical, and cardiac magnetic resonance (CMR) data to identify distinct phenogroups (PGs) of patients with beta-thalassemia intermedia (β-TI). We considered 138 β-TI patients consecutively enrolled in the Myocardial Iron Overload in Thalassemia (MIOT) Network who underwent MR for the quantification of hepatic and cardiac iron overload (T2* technique), the assessment of biventricular size and function and atrial dimensions (cine images), and the detection of replacement myocardial fibrosis (late gadolinium enhancement technique). Three mutually exclusive phenogroups were identified based on unsupervised hierarchical clustering of principal components: PG1, women; PG2, patients with replacement myocardial fibrosis, increased biventricular volumes and masses, and lower left ventricular ejection fraction; and PG3, men without replacement myocardial fibrosis, but with increased biventricular volumes and masses and lower left ventricular ejection fraction. The hematochemical parameters and the hepatic and cardiac iron levels did not contribute to the PG definition. PG2 exhibited a significantly higher risk of future cardiovascular events (heart failure, arrhythmias, and pulmonary hypertension) than PG1 (hazard ratio-HR = 10.5; p = 0.027) and PG3 (HR = 9.0; p = 0.038). Clustering emerged as a useful tool for risk stratification in TI, enabling the identification of three phenogroups with distinct clinical and prognostic characteristics.

AI-Based Fully Automated Left Atrioventricular Coupling Index as a Prognostic Marker in Patients Undergoing Stress CMR

BACKGROUND

The left atrioventricular coupling index (LACI) is a strong and independent predictor of heart failure (HF) in individuals without clinical cardiovascular disease. Its prognostic value is not established in patients with cardiovascular disease.

OBJECTIVES

This study sought to determine in patients undergoing stress cardiac magnetic resonance (CMR) whether fully automated artificial intelligence-based LACI can provide incremental prognostic value to predict HF.

METHODS

Between 2016 and 2018, the authors conducted a longitudinal study including all consecutive patients with abnormal (inducible ischemia or late gadolinium enhancement) vasodilator stress CMR. Control subjects with normal stress CMR were selected using propensity score matching. LACI was defined as the ratio of left atrial to left ventricular end-diastolic volumes. The primary outcome included hospitalization for acute HF or cardiovascular death. Cox regression was used to evaluate the association of LACI with the primary outcome after adjustment for traditional risk factors.

RESULTS

In 2,134 patients (65 ± 12 years, 77% men, 1:1 matched patients [1,067 with normal and 1,067 with abnormal CMR]), LACI was positively associated with the primary outcome (median follow-up: 5.2 years [IQR: 4.8-5.5 years]) before and after adjustment for risk factors in the overall propensity-matched population (adjusted HR: 1.18 [95% CI: 1.13-1.24]), in patients with abnormal CMR (adjusted HR per 0.1% increment: 1.22 [95% CI: 1.14-1.30]), and in patients with normal CMR (adjusted HR per 0.1% increment: 1.12 [95% CI: 1.05-1.20]) (all P < 0.001). After adjustment, a higher LACI of ≥25% showed the greatest improvement in model discrimination and reclassification over and above traditional risk factors and stress CMR findings (C-index improvement: 0.16; net reclassification improvement = 0.388; integrative discrimination index = 0.153, all P < 0.001; likelihood ratio test P < 0.001).

CONCLUSIONS

LACI is independently associated with hospitalization for HF and cardiovascular death in patients undergoing stress CMR, with an incremental prognostic value over traditional risk factors including inducible ischemia and late gadolinium enhancement.

Latest Updates in Heart Failure Imaging

Heart failure (HF), a challenging and heterogeneous syndrome, still remains a major health problem worldwide, despite all the advances in prevention, diagnosis, and treatment of cardiovascular disease. Cardiac imaging plays a pivotal role in the classification of HF, accurate diagnosis of underlying etiology and decision-making. Integration of other imaging techniques such as cardiac magnetic resonance, nuclear imaging, and exercise imaging testing is important to characterize HF accurately. This article reviews the role of multimodality imaging to diagnose patients with HF.

Differentiation of acute non-ST elevation myocardial infarction and acute infarct-like myocarditis by visual pattern analysis: a head-to-head comparison of different cardiac MR techniques

OBJECTIVES

Parametric cardiac magnetic resonance (CMR) techniques have improved the diagnosis of pathologies. However, the primary tool for differentiating non-ST elevation myocardial infarction (NSTEMI) from myocarditis is still a visual assessment of conventional signal-intensity-based images. This study aimed at analyzing the ability of parametric compared to conventional techniques to visually differentiate ischemic from non-ischemic myocardial injury patterns.

METHODS

Twenty NSTEMI patients, twenty infarct-like myocarditis patients, and twenty controls were examined using cine, T2-weighted CMR (T2w) and late gadolinium enhancement (LGE) imaging and T1/T2 mapping on a 1.5 T scanner. CMR images were presented in random order to two experienced fully blinded observers, who had to assign them to three categories by a visual analysis: NSTEMI, myocarditis, or healthy.

RESULTS

The conventional approach (cine, T2w and LGE combined) had the best diagnostic accuracy with 92% (95%CI: 81-97) for NSTEMI and 86% (95%CI: 71-94) for myocarditis. The diagnostic accuracies using T1 maps were 88% (95%CI: 74-95) and 80% (95%CI: 62-91), 84% (95%CI: 67-93) and 74% (95%CI: 54-87) for LGE, and 83% (95%CI: 66-92) and 73% (95%CI: 53-87) for T2w. The accuracies for cine (72% (95%CI: 52-86) and 60% (95%CI: 38-78)) and T2 maps (62% (95%CI: 40-79) and 47% (95%CI: 28-68)) were significantly lower compared to the conventional approach (p < 0.001 and p < 0.0001).

CONCLUSIONS

The conventional approach provided a reliable visual discrimination between NSTEMI, myocarditis, and controls. The diagnostic accuracy of a visual pattern analysis of T1 maps was not significantly inferior, whereas the diagnostic accuracy of T2 maps was not sufficient in this context.

CLINICAL RELEVANCE STATEMENT

The ability of parametric compared to conventional CMR techniques to visually differentiate ischemic from non-ischemic myocardial injury patterns can avoid potentially unnecessary invasive coronary angiography and help to shorten CMR protocols and to reduce the need of gadolinium contrast agents.

KEY POINTS

• A visual differentiation of ischemic from non-ischemic patterns of myocardial injury is reliably achieved by a combination of conventional CMR techniques (cine, T2-weighted and LGE imaging). • There is no significant difference in accuracies between visual pattern analysis on native T1 maps without providing quantitative values and a conventional combined approach for differentiating non-ST elevation myocardial infarction, infarct-like myocarditis, and controls. • T2 maps do not provide a sufficient diagnostic accuracy for visual pattern analysis for differentiating non-ST elevation myocardial infarction, infarct-like myocarditis, and controls.

An Effective Approach to Improve the Automatic Segmentation and Classification Accuracy of Brain Metastasis by Combining Multi-phase Delay Enhanced MR Images

The objective of this study is to analyse the diffusion rule of the contrast media in multi-phase delayed enhanced magnetic resonance (MR) T1 images using radiomics and to construct an automatic classification and segmentation model of brain metastases (BM) based on support vector machine (SVM) and Dpn-UNet. A total of 189 BM patients with 1047 metastases were enrolled. Contrast-enhanced MR images were obtained at 1, 3, 5, 10, 18, and 20 min following contrast medium injection. The tumour target volume was delineated, and the radiomics features were extracted and analysed. BM segmentation and classification models in the MR images with different enhancement phases were constructed using Dpn-UNet and SVM, and differences in the BM segmentation and classification models with different enhancement times were compared. (1) The signal intensity for BM decreased with time delay and peaked at 3 min. (2) Among the 144 optimal radiomics features, 22 showed strong correlation with time (highest R-value = 0.82), while 41 showed strong correlation with volume (highest R-value = 0.99). (3) The average dice similarity coefficients of both the training and test sets were the highest at 10 min for the automatic segmentation of BM, reaching 0.92 and 0.82, respectively. (4) The areas under the curve (AUCs) for the classification of BM pathology type applying single-phase MRI was the highest at 10 min, reaching 0.674. The AUC for the classification of BM by applying the six-phase image combination was the highest, reaching 0.9596, and improved by 42.3% compared with that by applying single-phase images at 10 min. The dynamic changes of contrast media diffusion in BM can be reflected by multi-phase delayed enhancement based on radiomics, which can more objectively reflect the pathological types and significantly improve the accuracy of BM segmentation and classification.

Prognostic Value of Cardiac Magnetic Resonance Imaging in Patients With a Working Diagnosis of MINOCA-An Outcome Study With up to 10 Years of Follow-Up

BACKGROUND

Patients with a working diagnosis of myocardial infarction with unobstructed coronary arteries (MINOCA) represent a heterogeneous cohort. The prognosis could vary substantially depending on the underlying cause. Although cardiac magnetic resonance (CMR) is considered a key diagnostic tool in these patients, there are limited data linking the CMR diagnosis with the outcome.

METHODS

This study is a prospective outcomes registry of consecutive patients presenting with a working diagnosis of MINOCA who were clinically referred for CMR at an academic hospital from October 2003 to February 2020. We assessed the relationships between the prespecified CMR diagnoses of acute myocardial infarction (AMI), myocarditis, nonischemic cardiomyopathy (NICM), normal CMR study, and major adverse cardiac events (MACEs).

RESULTS

Of 252 patients, the CMR diagnosis was AMI in 63 (25%), myocarditis in 33 (13%), NICM in 111 (44%), normal CMR in 37 (15%), and other diagnoses in 8 (3%). A specific nonischemic cause was diagnosed allowing true MINOCA to be ruled-out in 57% of the cohort. During up to 10 years of follow-up (1595 patient-years), MACE occurred in 84 patients (33%), which included 64 deaths (25%). The unadjusted cumulative 10-year rate of MACE was 47% in AMI, 24% in myocarditis, 50% in NICM, and 3.5% in patients with a normal CMR (Log-rank P<0.001). The CMR diagnosis provided incremental prognostic value over clinical factors including age, gender, coronary artery disease risk factors, presentation with ST-elevation, and peak troponin (incremental χ² 17.9, P<0.001); and patients with diagnoses of AMI, myocarditis, and NICM had worse MACE-free survival than patients with a normal CMR.

CONCLUSIONS

In patients with a working diagnosis of MINOCA, CMR allows ruling-out true MINOCA in over half of the patients. CMR diagnoses of AMI, myocarditis, and NICM are associated with worse MACE-free survival, whereas a normal CMR study portends a benign prognosis.

Left-to-right ventricular volume ratio and outcome in heart failure with preserved ejection fraction

BACKGROUND

Age-specific and gender-specific reference values for left ventricular (LV) and right ventricle volumes are available. The prognostic implications of the ratio between these volumes in heart failure and preserved ejection fraction (HFpEF) have never been evaluated.

METHODS

We examined all HFpEF outpatients undergoing a cardiac magnetic resonance from 2011 to 2021. The left-to-right ventricular volume ratio (LRVR) was defined as the ratio between the LV and right ventricle end-diastolic volume indexes (LVEDVi/RVEDVi).

RESULTS

Among 159 patients [median age 58 years (interquartile range 49-69), 64% men, LV ejection fraction 60% (54-70%)] the median LRVR was 1.21 (1.07-1.40). Over 3.5 years (1.5-5.0), 23 patients (15%) experienced all-cause death or heart failure hospitalization, and 22 (14%) cardiovascular death or heart failure hospitalization. The risk of all-cause death or heart failure hospitalization increased with an LRVR less than 1.0 or at least 1.4. An LRVR less than 1.0 was associated with a higher risk of all-cause death or heart failure hospitalization [hazard ratio 5.95, 95% confidence interval (CI) 1.67-21.28; P = 0.006] and cardiovascular death or heart failure hospitalization (hazard ratio 5.68, 95% CI 1.58-20.35; P = 0.008) as compared with LRVR 1.0-1.3. Furthermore, an LRVR at least 1.4 was associated with a higher risk of all-cause death or heart failure hospitalization (hazard ratio 4.10, 95% CI 1.58-10.61; P = 0.004) and cardiovascular death or heart failure hospitalization (hazard ratio 3.71, 95% CI 1.41-9.79; P = 0.008) as compared with LRVR 1.0-1.3. These results were confirmed in patients without dilation of either ventricle.

CONCLUSION

LRVR values less than 1.0 or at least 1.4 are associated with worse outcomes in HFpEF. LRVR may become a valuable tool for risk prediction in HFpEF.

Infarct-like versus Non-Infarct-like Clinical Presentation of Acute Myocarditis: Comparison of Cardiac Magnetic Resonance (CMR) Findings

BACKGROUND

The clinical presentation of acute myocarditis (AM) is widely variable, ranging from a subclinical disease to an infarct-like syndrome. Cardiac magnetic resonance (CMR) has become the reference non-invasive diagnostic tool for suspected AM, allowing the identification of the various hallmarks of myocardial inflammation (edema, fibrosis, and hyperemia). The aim of the study was to investigate any differences in morphological, functional, and tissue characterization CMR parameters between infarct-like AM in patients with unobstructed coronary arteries and non-infarct-like AM, diagnosed according to the original Lake-Louise Criteria (LLC); Methods: We retrospectively selected 39 patients diagnosed with AM according to LLC, divided into 2 groups according to the clinical presentation: infarct-like in group 1 patients and non-infarct-like in group 2 patients. CMR morphologic, functional, and tissue characterization parameters were analyzed and compared.

RESULTS

In group 1, CMR tissue characterization parameters were mainly altereda in septal location with mesocardial myocardial involvement; in group 2, CMR tissue characterization parameters were mainly altered in a lateral location with subepicardial myocardial involvement mainly at the mid-cavity. No significant differences in morphological or functional parameters were observed between the two study groups.

CONCLUSIONS

Our results showed differences in the localization and distribution of myocardial tissue damage assessed by CMR among forms of AM accompanied by an infarct-like clinical presentation compared with non-infarct-like presentations of AM. The mechanisms underlying the different preferential sites of damage observed in our study are not known, and we do not exclude the possibility of their prognostic implications.

Imaging Predictors of Left Ventricular Functional Recovery after Reperfusion Therapy of ST-Elevation Myocardial Infarction Assessed by Cardiac Magnetic Resonance

BACKGROUND

Left ventricular global longitudinal strain (LV GLS) is a superior predictor of adverse cardiac events in patients with myocardial infarction and heart failure. We investigated the ability of morphological features of infarcted myocardium to detect acute left ventricular (LV) dysfunction and predict LV functional recovery after three months in patients with acute ST-segment elevation myocardial infarction (STEMI).

METHODS

Sixty-six STEMI patients were included in the C-reactive protein (CRP) apheresis in Acute Myocardial Infarction Study (CAMI-1). LV ejection fraction (LVEF), LV GLS, LV global circumferential strain (LV GCS), infarct size (IS), area-at-risk (AAR), and myocardial salvage index (MSI) were assessed by CMR 5 ± 3 days (baseline) and 12 ± 2 weeks after (follow-up) the diagnosis of first acute STEMI.

RESULTS

Significant changes in myocardial injury parameters were identified after 12 weeks of STEMI diagnosis. IS decreased from 23.59 ± 11.69% at baseline to 18.29 ± 8.32% at follow-up (p < 0.001). AAR and MVO also significantly reduced after 12 weeks. At baseline, there were reasonably moderate correlations between IS and LVEF (r = -0.479, p < 0.001), LV GLS (r = 0.441, p < 0.001) and LV GCS (r = 0.396, p = 0.001) as well as between AAR and LVEF (r = -0.430, p = 0.003), LV GLS (r = 0.501, p < 0.001) and weak with LV GCS (r = 0.342, p = 0.020). At follow-up, only MSI and change in LV GCS over time showed a weak but significant correlation (r = -0.347, p = 0.021). Patients with larger AAR at baseline improved more in LVEF (p = 0.019) and LV GLS (p = 0.020) but not in LV GCS.

CONCLUSION

The CMR tissue characteristics of myocardial injury correlate with the magnitude of LV dysfunction during the acute stage of STEMI. AAR predicts improvement in LVEF and LV GLS, while MSI is a sensitive marker of LV GCS recovery at three months follow-up after STEMI.

Septal Midwall Late Gadolinium Enhancement in Ischemic Cardiomyopathy and Nonischemic Dilated Cardiomyopathy-Characteristics and Prognosis

Septal midwall late gadolinium enhancement (LGE) is a characteristic finding on cardiac magnetic resonance imaging (CMR) in nonischemic dilated cardiomyopathy (DCM) and is associated with adverse events. Its significance in ischemic cardiomyopathy (ICM) is unknown. With this multicenter observational study, we aimed to study the characteristics of septal midwall LGE and evaluate its prognostic value in ICM. A total of 1,084 patients with an impaired left ventricular (LV) ejection fraction (<50%) on LGE-CMR, either because of ICM (53%) or DCM, were included retrospectively. Septal midwall LGE was defined as midmyocardial stripe-like or patchy LGE in septal segments and was present in 10% of patients with ICM compared with 34% of patients with DCM (p <0.001). It was significantly associated with larger LV volumes and lower LV ejection fraction, irrespective of etiology. The primary endpoint was all-cause mortality and secondary endpoint was ventricular arrhythmias (VAs), including resuscitated cardiac arrest, sustained VA, and appropriate implantable cardioverter-defibrillator (ICD) therapy. During a median follow-up of 2.7 years, we found a significant association between septal midwall LGE and mortality in patients with DCM (hazard ratio [HR] 1.92, p = 0.03), but not in patients with ICM (HR 1.35, p = 0.39). Risk of VAs was significantly higher in patients with septal midwall LGE on CMR, both in DCM (HR 2.80, p <0.01) and in ICM (HR 2.70, p <0.01). In conclusion, septal midwall LGE, typically seen in DCM, was also present in 10% of patients with ICM and was associated with increased LV dilation and worse function, irrespective of etiology. When present, septal midwall LGE was associated with adverse outcome.

Safety and incremental prognostic value of stress cardiovascular magnetic resonance in patients with known chronic kidney disease

BACKGROUND

Cardiovascular disease (CVD) is the main cause of mortality in patients with chronic kidney disease (CKD). Although several studies have demonstrated the consistently high prognostic value of stress cardiovascular magnetic resonance (CMR), its prognostic value in patients with CKD is not well established. We aimed to assess the safety and the incremental prognostic value of vasodilator stress perfusion CMR in consecutive symptomatic patients with known CKD.

METHODS

Between 2008 and 2021, we conducted a retrospective dual center study with all consecutive symptomatic patients with known stage 3 CKD, defined by estimated glomerular filtration rate (eGFR) between 30 and 60 ml/min/1.73 m2, referred for vasodilator stress CMR. All patients with eGFR < 30 ml/min/1.73 m2 (n = 62) were excluded due the risk of nephrogenic systemic fibrosis. All patients were followed for the occurrence of major adverse cardiovascular events (MACE) defined as cardiac death or recurrent nonfatal myocardial infarction (MI). Cox regression analysis was used to determine the prognostic value of stress CMR parameters.

RESULTS

Of 825 patients with known CKD (71.4 ± 8.8 years, 70% men), 769 (93%) completed the CMR protocol. Follow-up was available in 702 (91%) (median follow-up 6.4 (4.0-8.2) years). Stress CMR was well tolerated without occurrence of death or severe adverse event related to the injection of gadolinium or cases of nephrogenic systemic fibrosis. The presence of inducible ischemia was associated with the occurrence of MACE (hazard ratio [HR] 12.50; 95% confidence interval [CI] 7.50-20.8; p < 0.001). In multivariable analysis, ischemia and late gadolinium enhancement were independent predictors of MACE (HR 15.5; 95% CI 7.72 to 30.9; and HR 4.67 [95% CI 2.83-7.68]; respectively, both p < 0.001). After adjustment, stress CMR findings showed the best improvement in model discrimination and reclassification above traditional risk factors (C-statistic improvement: 0.13; NRI = 0.477; IDI = 0.049).

CONCLUSIONS

In patients with known stage 3 CKD, stress CMR is safe and its findings have an incremental prognostic value to predict MACE over traditional risk factors.

Cardiac Magnetic Resonance in HCM Phenocopies: From Diagnosis to Risk Stratification and Therapeutic Management

Hypertrophic cardiomyopathy (HCM) is a genetic heart disease characterized by the thickening of the heart muscle, which can lead to symptoms such as chest pain, shortness of breath, and an increased risk of sudden cardiac death. However, not all patients with HCM have the same underlying genetic mutations, and some have conditions that resemble HCM but have different genetic or pathophysiological mechanisms, referred to as phenocopies. Cardiac magnetic resonance (CMR) imaging has emerged as a powerful tool for the non-invasive assessment of HCM and its phenocopies. CMR can accurately quantify the extent and distribution of hypertrophy, assess the presence and severity of myocardial fibrosis, and detect associated abnormalities. In the context of phenocopies, CMR can aid in the differentiation between HCM and other diseases that present with HCM-like features, such as cardiac amyloidosis (CA), Anderson-Fabry disease (AFD), and mitochondrial cardiomyopathies. CMR can provide important diagnostic and prognostic information that can guide clinical decision-making and management strategies. This review aims to describe the available evidence of the role of CMR in the assessment of hypertrophic phenotype and its diagnostic and prognostic implications.

Utility of cardiac imaging in patients with ventricular tachycardia

Ventricular tachycardia (VT) is a life-threatening arrhythmia that may be idiopathic or result from structural heart disease. Cardiac imaging is critical in the diagnostic workup and risk stratification of patients with VT. Data gained from cardiac imaging provides information on likely mechanisms and sites of origin, as well as risk of intervention. Pre-procedural imaging can be used to plan access route(s) and identify patients where post-procedural intensive care may be required. Integration of cardiac imaging into electroanatomical mapping systems during catheter ablation procedures can facilitate the optimal approach, reduce radiation dose, and may improve clinical outcomes. Intraprocedural imaging helps guide catheter position, target substrate, and identify complications early. This review summarises the contemporary imaging modalities used in patients with VT, and their uses both pre-procedurally and intra-procedurally.

Korean Society of Heart Failure Guidelines for the Management of Heart Failure: Definition and Diagnosis

The Korean Society of Heart Failure guidelines aim to provide physicians with evidence-based recommendations for diagnosing and managing patients with heart failure (HF). In Korea, the prevalence of HF has been rapidly increasing in the last 10 years. HF has recently been classified into HF with reduced ejection fraction (HFrEF), HF with mildly reduced ejection fraction (EF), and HF with preserved EF (HFpEF). Moreover, the availability of newer therapeutic agents has led to an increased emphasis on the appropriate diagnosis of HFpEF. Accordingly, this part of the guidelines will mainly cover the definition, epidemiology, and diagnosis of HF.

Korean Society of Heart Failure Guidelines for the Management of Heart Failure: Definition and Diagnosis

The Korean Society of Heart Failure guidelines aim to provide physicians with evidence-based recommendations for diagnosing and managing patients with heart failure (HF). In Korea, the prevalence of HF has been rapidly increasing in the last 10 years. HF has recently been classified into HF with reduced ejection fraction (EF), HF with mildly reduced EF, and HF with preserved EF (HFpEF). Moreover, the availability of newer therapeutic agents has led to an increased emphasis on the appropriate diagnosis of HFpEF. Accordingly, this part of the guidelines will mainly cover the definition, epidemiology, and diagnosis of HF.

Cardiovascular magnetic resonance for evaluation of cardiac involvement in COVID-19: recommendations by the Society for Cardiovascular Magnetic Resonance

Coronavirus disease 2019 (COVID-19) is an ongoing global pandemic that has affected nearly 600 million people to date across the world. While COVID-19 is primarily a respiratory illness, cardiac injury is also known to occur. Cardiovascular magnetic resonance (CMR) imaging is uniquely capable of characterizing myocardial tissue properties in-vivo, enabling insights into the pattern and degree of cardiac injury. The reported prevalence of myocardial involvement identified by CMR in the context of COVID-19 infection among previously hospitalized patients ranges from 26 to 60%. Variations in the reported prevalence of myocardial involvement may result from differing patient populations (e.g. differences in severity of illness) and the varying intervals between acute infection and CMR evaluation. Standardized methodologies in image acquisition, analysis, interpretation, and reporting of CMR abnormalities across would likely improve concordance between studies. This consensus document by the Society for Cardiovascular Magnetic Resonance (SCMR) provides recommendations on CMR imaging and reporting metrics towards the goal of improved standardization and uniform data acquisition and analytic approaches when performing CMR in patients with COVID-19 infection.

Cardiac sarcoidosis

The diagnostic yield of endomyocardial biopsy in cardiac sarcoidosis (CS) is quite low because of the patchy involvement, and for the diagnosis of CS, existing guidelines required histological confirmation. Therefore, especially for isolated CS, diagnosis consistent with the guidelines cannot be made in a large number of patients. With recent developments in imaging modalities such as cardiac magnetic resonance and 18-fluorodeoxyglucose positron emission tomography, diagnosing CS has become easier and diagnostic criteria for CS not compulsorily requiring histological confirmation have been suggested. Despite significant advances in diagnostic tools, large-scale studies that can guide treatment plans are still lacking, and treatment has relied on the experience accumulated over the past years and the consensus of experts. However, opinions vary, depending on the situation, which is quite puzzling for the physician treating CS. Moreover, with the advent of new immunosuppressant agents, these new drugs have been applied under the assumption that the effect of immunosuppression is not much different from that of other well-known autoimmune diseases that require immunosuppression. However, we should wait to see the beneficial effects of these new immunosuppressants before we attempt to apply these agents in our clinical practice. This review summarises the widely used diagnostic criteria, current diagnostic modalities and recommended treatments for sarcoidosis. We have added our opinions on selecting or modifying diagnostic and treatment plans from the diverse current recommendations.

Characteristics and Prognosis of a Contemporary Cohort with Myocardial Infarction with Non-Obstructed Coronary Arteries (MINOCA) Presenting Different Patterns of Late Gadolinium Enhancements in Cardiac Magnetic Resonance Imaging

BACKGROUND

To analyze the characteristics and prognosis of a contemporary cohort of patients with myocardial infarction with non-obstructed coronaries (MINOCA) were referred for cardiac magnetic resonance (CMR) imaging, focusing on late gadolinium enhancement (LGE) patterns.

METHODS

We retrospectively examined and prospectively followed up with 135 patients (49 ± 21 years old, 48% female) undergoing CMR imaging due to a MINOCA diagnosis from 2014 to 2016. We grouped and analyzed the sample according to ischemic (focal or transmural) and non-ischemic LGE patterns. The primary outcome was cardiac-related death; the secondary outcome was a composite of cardiac-related rehospitalizations, the new occurrence of acute myocardial infarction (AMI), heart failure (HF), or arrhythmias.

RESULTS

CMR exams were performed after a median of 28 days from the acute event. One-third of the ischemic MINOCA were first managed as myocarditis, while CMR helped to adopt a different therapy regimen in 22% of patients (30/135). After a median follow-up of 2.3 years, more cardiac-related deaths occurred in the ischemic than non-ischemic group (2 vs. 1, p = 0.36), but it was not statistically significant. The ischemic group also experienced more cardiac-related-rehospitalizations (42%, p < 0.001). In a multivariable Cox regression model, dyslipidemia, reduced left ventricular ejection fraction, ST-elevation at the hospitalization, and the LGE transmural pattern were the independent predictors of cardiac-related rehospitalizations.

CONCLUSIONS

In a contemporary cohort of MINOCA patients who underwent CMR, ischemic and non-ischemic patterns had distinct features and outcomes. Among the MINOCA patients, CMR can identify patients at higher risk who require more aggressive therapeutic approached and strict follow-up.

Native T1 mapping for the diagnosis of cardiac amyloidosis in patients with left ventricular hypertrophy

BACKGROUND

Cardiac magnetic resonance (CMR) with parametric mapping can improve the characterization of myocardial tissue. We studied the diagnostic value of native T1 mapping to detect cardiac amyloidosis in patients with left ventricular (LV) hypertrophy.

METHODS

One hundred twenty-five patients with increased LV wall thickness (≥ 12 mm end-diastole) who received clinical CMR in a 3 T scanner between 2017 and 2020 were included. 31 subjects without structural heart disease served as controls. Native T1 was measured as global mean value from 3 LV short axis slices. The study was registered at German clinical trial registry (DRKS00022048).

RESULTS

Mean age of the patients was 66 ± 14 years, 83% were males. CA was present in 24 patients, 21 patients had hypertrophic cardiomyopathy (HCM), 80 patients suffered from hypertensive heart disease (HHD). Native T1 times were higher in patients with CA (1409 ± 59 ms, p < 0.0001) compared to healthy controls (1225 ± 21 ms), HCM (1266 ± 44 ms) and HHD (1257 ± 41 ms). HCM and HHD patients did not differ in their native T1 times but were increased compared to control (p < 0.01). ROC analysis of native T1 demonstrated an area under the curve for the detection of CA vs. HCM and HHD of 0.9938 (p < 0.0001), which was higher than that of extracellular volume (0.9876) or quantitative late gadolinium enhancement (0.9406; both p < 0.0001). The optimal cut-off value of native T1 to diagnose CA was 1341 ms (sensitivity 100%, specificity 97%).

CONCLUSION

Non-contrast CMR imaging with native T1 mapping provides high diagnostic accuracy to diagnose cardiac amyloidosis in patients with left ventricular hypertrophy.

Optimization of null point in Look-Locker images for myocardial late gadolinium enhancement imaging using deep learning and a smartphone

OBJECTIVES

To determine the optimal inversion time (TI) from Look-Locker scout images using a convolutional neural network (CNN) and to investigate the feasibility of correcting TI using a smartphone.

METHODS

In this retrospective study, TI-scout images were extracted using a Look-Locker approach from 1113 consecutive cardiac MR examinations performed between 2017 and 2020 with myocardial late gadolinium enhancement. Reference TI null points were independently determined visually by an experienced radiologist and an experienced cardiologist, and quantitatively measured. A CNN was developed to evaluate deviation of TI from the null point and then implemented in PC and smartphone applications. Images on 4 K or 3-megapixel monitors were captured by a smartphone, and CNN performance on each monitor was determined. Optimal, undercorrection, and overcorrection rates using deep learning on the PC and smartphone were calculated. For patient analysis, TI category differences in pre- and post-correction were evaluated using the TI null point used in late gadolinium enhancement imaging.

RESULTS

For PC, 96.4% (772/749) of images were classified as optimal, with under- and overcorrection rates of 1.2% (9/749) and 2.4% (18/749), respectively. For 4 K images, 93.5% (700/749) of images were classified as optimal, with under- and overcorrection rates of 3.9% (29/749) and 2.7% (20/749), respectively. For 3-megapixel images, 89.6% (671/749) of images were classified as optimal, with under- and overcorrection rates of 3.3% (25/749) and 7.0% (53/749), respectively. On patient-based evaluations, subjects classified as within optimal range increased from 72.0% (77/107) to 91.6% (98/107) using the CNN.

CONCLUSIONS

Optimizing TI on Look-Locker images was feasible using deep learning and a smartphone.

KEY POINTS

• A deep learning model corrected TI-scout images to within optimal null point for LGE imaging. • By capturing the TI-scout image on the monitor with a smartphone, the deviation of the TI from the null point can be immediately determined. • Using this model, TI null points can be set to the same degree as that by an experienced radiological technologist.