Recurrent non-rheumatic streptococcal myocarditis: 18F-FDG PET/CMR findings.

Nonrheumatic streptococcal myocarditis (NRSM) is a life-threatening complication of streptococcal pharyngitis. We report the history of a 35-year-old man with recurrent NRSM and the related 18F-FDG PET/CMR findings.18F-FDG PET/CMR represents cutting-edge imaging for the diagnosis and follow-up of myocarditis, allowing myocardial inflammation assessment, and the distinction between active disease and myocardial scarring.

Deep Learning to Classify AL versus ATTR Cardiac Amyloidosis MR Images.

The aim of this work was to compare the classification of cardiac MR-images of AL versus ATTR amyloidosis by neural networks and by experienced human readers. Cine-MR images and late gadolinium enhancement (LGE) images of 120 patients were studied (70 AL and 50 TTR). A VGG16 convolutional neural network (CNN) was trained with a 5-fold cross validation process, taking care to strictly distribute images of a given patient in either the training group or the test group. The analysis was performed at the patient level by averaging the predictions obtained for each image. The classification accuracy obtained between AL and ATTR amyloidosis was 0.750 for cine-CNN, 0.611 for Gado-CNN and between 0.617 and 0.675 for human readers. The corresponding AUC of the ROC curve was 0.839 for cine-CNN, 0.679 for gado-CNN (p < 0.004 vs. cine) and 0.714 for the best human reader (p < 0.007 vs. cine). Logistic regression with cine-CNN and gado-CNN, as well as analysis focused on the specific orientation plane, did not change the overall results. We conclude that cine-CNN leads to significantly better discrimination between AL and ATTR amyloidosis as compared to gado-CNN or human readers, but with lower performance than reported in studies where visual diagnosis is easy, and is currently suboptimal for clinical practice.

Cutting-Edge Imaging of Cardiac Metastases from Neuroendocrine Tumors: Lesson from a Case Series.

With the increasing availability of high-performance medical imaging for the management of patients with neuroendocrine tumors (NETs), a progressive growth of asymptomatic and incidentally detected cardiac metastases (CMs) has been observed in the recent years. In clinical practice, CMs of NENs are often incidentally detected by whole-body 68Ga-labeled somatostatin analogs or 18F-fluorodihydroxyphenylalanine positron emission tomography/computed tomography, and afterwards accurately characterized by cardiac magnetic resonance (CMR) and/or gated cardiac computed tomography when CMR is contraindicated or not available. The interpreting physician should familiarize with the main imaging features of CM, a finding that may be encountered in NETs patients more than previously thought. Herein, we present a case series of four patients with CMs from small-intestine NETs highlighting strengths and weaknesses of a multimodality imaging approach in clinical practice.

Classification of Cardiomyopathies from MR Cine Images Using Convolutional Neural Network with Transfer Learning.

The automatic classification of various types of cardiomyopathies is desirable but has never been performed using a convolutional neural network (CNN). The purpose of this study was to evaluate currently available CNN models to classify cine magnetic resonance (cine-MR) images of cardiomyopathies. METHOD: Diastolic and systolic frames of 1200 cine-MR sequences of three categories of subjects (395 normal, 411 hypertrophic cardiomyopathy, and 394 dilated cardiomyopathy) were selected, preprocessed, and labeled. Pretrained, fine-tuned deep learning models (VGG) were used for image classification (sixfold cross-validation and double split testing with hold-out data). The heat activation map algorithm (Grad-CAM) was applied to reveal salient pixel areas leading to the classification. RESULTS: The diastolic-systolic dual-input concatenated VGG model cross-validation accuracy was 0.982 ± 0.009. Summed confusion matrices showed that, for the 1200 inputs, the VGG model led to 22 errors. The classification of a 227-input validation group, carried out by an experienced radiologist and cardiologist, led to a similar number of discrepancies. The image preparation process led to 5% accuracy improvement as compared to nonprepared images. Grad-CAM heat activation maps showed that most misclassifications occurred when extracardiac location caught the attention of the network. CONCLUSIONS: CNN networks are very well suited and are 98% accurate for the classification of cardiomyopathies, regardless of the imaging plane, when both diastolic and systolic frames are incorporated. Misclassification is in the same range as inter-observer discrepancies in experienced human readers.

Presence of active myocarditis at the 6 month follow-up appointment for a severe form of COVID-19: a case report.

Here, we present the case of an 81-year-old male patient, who was hospitalized for a severe form of COVID-19. Transthoracic echocardiogram (TTE) performed 1 month after symptom onset was normal. Respiratory evolution was favourable, and the patient was discharged at Day 78. At 6 months, despite a good functional recovery, he presented pulmonary sequelae, and the TTE revealed a clear reduction of left ventricular ejection fraction (LVEF) and mild LV dilatation without cardiac symptoms. The cardiac magnetic resonance (CMR) using Lake Louise Criteria (LLC), T1 and T2 mapping showed focal infero-basal LV wall oedema, elevated T1 and T2 myocardial relaxation times especially in basal inferior and infero-lateral LV walls, and sub-epicardial late gadolinium enhancement in those LV walls. The diagnosis of active myocarditis was raised especially based on TTE abnormalities and CMR LLC, T1 and T2 mapping. Currently, we are not aware of published reports of a 6 month post-COVID-19 active myocarditis.

Advantages of 18F-FDG PET/CT Imaging over Modified Duke Criteria and Clinical Presumption in Patients with Challenging Suspicion of Infective Endocarditis.

According to European Society of Cardiology guidelines (ESC2015) for infective endocarditis (IE) management, modified Duke criteria (mDC) are implemented with a degree of clinical suspicion degree, leading to grades such as "possible" or "rejected" IE despite a persisting high level of clinical suspicion. Herein, we evaluate the 18F-FDG PET/CT diagnostic and therapeutic impact in IE suspicion, with emphasis on possible/rejected IE with a high clinical suspicion. Excluding cases of definite IE diagnosis, 53 patients who underwent 18F-FDG PET/CT for IE suspicion were selected and afterwards classified according to both mDC (possible IE/Duke 1, rejected IE/Duke 0) and clinical suspicion degree (high and low IE suspicion). The final status regarding IE diagnosis (gold standard) was based on the multidisciplinary decision of the Endocarditis Team, including the 'imaging specialist'. PET/CT images of the cardiac area were qualitatively interpreted and the intensity of each focus of extra-physiologic 18F-FDG uptake was evaluated by a maximum standardized uptake value (SUVmax) measurement. Extra-cardiac 18F-FDG PET/CT pathological findings were considered to be a possible embolic event, a possible source of IE, or even a concomitant infection. Based on the Endocarditis Team consensus, final diagnosis of IE was retained in 19 (36%) patients and excluded in 34 (64%). With a sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and global accuracy of 79%, 100%, 100%, 89%, and 92%, respectively, PET/CT performed significantly better than mDC (p = 0.003), clinical suspicion degree (p = 0.001), and a combination of both (p = 0.001) for IE diagnosis. In 41 patients with possible/rejected IE but high clinical suspicion, sensitivity, specificity, PPV, NPV, and global accuracies were 78%, 100%, 100%, 85%, and 90%, respectively. Moreover, PET/CT contributed to patient management in 24 out of 53 (45%) cases. 18F-FDG PET/CT represents a valuable diagnostic tool that could be proposed for challenging IE cases with significant differences between mDC and clinical suspicion degree. 18F-FDG PET/CT allows a binary diagnosis (definite or rejected IE) by removing uncertain diagnostic situations, thus improving patient therapeutic management.

Deep Learning Supplants Visual Analysis by Experienced Operators for the Diagnosis of Cardiac Amyloidosis by Cine-CMR.

BACKGROUND: Diagnosing cardiac amyloidosis (CA) from cine-CMR (cardiac magnetic resonance) alone is not reliable. In this study, we tested if a convolutional neural network (CNN) could outperform the visual diagnosis of experienced operators. METHOD: 119 patients with cardiac amyloidosis and 122 patients with left ventricular hypertrophy (LVH) of other origins were retrospectively selected. Diastolic and systolic cine-CMR images were preprocessed and labeled. A dual-input visual geometry group (VGG ) model was used for binary image classification. All images belonging to the same patient were distributed in the same set. Accuracy and area under the curve (AUC) were calculated per frame and per patient from a 40% held-out test set. Results were compared to a visual analysis assessed by three experienced operators. RESULTS: frame-based comparisons between humans and a CNN provided an accuracy of 0.605 vs. 0.746 (p < 0.0008) and an AUC of 0.630 vs. 0.824 (p < 0.0001). Patient-based comparisons provided an accuracy of 0.660 vs. 0.825 (p < 0.008) and an AUC of 0.727 vs. 0.895 (p < 0.002). CONCLUSION: based on cine-CMR images alone, a CNN is able to discriminate cardiac amyloidosis from LVH of other origins better than experienced human operators (15 to 20 points more in absolute value for accuracy and AUC), demonstrating a unique capability to identify what the eyes cannot see through classical radiological analysis.

Acute Myopericarditis in a Patient With Mild SARS-CoV-2 Respiratory Infection.

Herein is presented a case of a 71-year-old woman with mild SARS-CoV-2 respiratory infection who experienced acute myopericarditis diagnosed using clinical, biological, and electrocardiogram data and cardiac magnetic resonance imaging. The presented case highlights the risk of cardiac involvement, even in the absence of severe respiratory COVID-19 infection. The mechanisms involved in acute myocardial injury in SARS-CoV-2 infection are not well known and requires further studies to determine whether it is related to direct myocardial damage by the virus or to a systemic condition.

Nous présentons le cas d'une femme de 71 ans qui présentait une infection respiratoire légère causée par le virus SRAS-CoV-2 et qui a subi une myopéricardite aiguë diagnostiquée à partir de données cliniques, biologiques et électrocardiographiques et d'un examen d'imagerie par résonance magnétique cardiaque. Ce cas met en lumière le risque d'atteinte cardiaque chez les patients atteints de COVID-19, même en l'absence d'infection respiratoire grave. On ne connaît pas bien les mécanismes qui participent à l'atteinte myocardique aiguë chez les patients infectés par le virus SRAS-CoV-2, et des recherches plus poussées sont nécessaires pour déterminer si cette atteinte est causée directement par le virus ou si elle est due à un trouble systémique.

68Ga-DOTATOC PET for Treatment Efficacy Evaluation of Cardiac Sarcoidosis.

Cardiac sarcoidosis (CS) has a poor prognosis related to life-threating arrhythmias and heart failure. Treatment includes anti-inflammatory therapies and implantable pacemaker and/or cardioverter defibrillator. The presence of cardiac devices and physiologic myocardial glucose uptake are major limitations of both cardiac magnetic resonance and F-FDG PET/CT, reducing their diagnostic value. Somatostatin-based PET/CT has been proposed to detect active CS. Contrarily to F-FDG uptake, which reflects nonspecific leukocyte infiltration, Ga-DOTATOC may identify active granulomatosis. Herein, we underline the specificity of Ga-DOTATOC PET in challeging clinical situations including refractory CS, and chronic CS in patients with cardiac device, or false-positive F-FDG PET/CT results.

T1 mapping cardiac magnetic resonance imaging frequently detects subclinical diffuse myocardial fibrosis in systemic sclerosis patients.

OBJECTIVES: cardiac involvement is the second most frequent systemic sclerosis (SSc) related cause of death. It remains mostly asymptomatic in the early stage and is underdiagnosed with routine screening. Cardiac magnetic resonance imaging (CMR) could improve cardiac assessment of patients and noteworthily, new sequences allow the detection of diffuse myocardial fibrosis (DMF) by native T1 mapping. The aim of this study was to determine the prevalence of cardiac involvement by CMR native T1 mapping and its correlation with echocardiography data and non-cardiac manifestations in SSc patients. METHODS: patients fulfilling the ACR/EULAR classification criteria for SSc were prospectively included between 2014 and 2016. They underwent CMR at 1.5T, including native T1 and T2 mapping, and Late Gadolinium Enhancement (LGE) as a part of routine follow up. Routine biological tests (mainly BNP and CRP) were centralized in the hospital laboratory. RESULTS: seventy-two unselected patients were included. Thirty six patients (50%) had elevated T1 (ET1) (mean T1 1097±14 ms). CMR cardiac functional parameters were similar in ET1 and normal T1 (NT1). Echocardiography was normal in 18 (50%) of ET1. ET1 and NT1 groups were similar for cardiovascular risk factors and ischemic heart disease. ET1 was not correlated with any clinical or echocardiographic parameter or antibody profile. Thirty-six percent of patients with ET1 had no cardiac symptoms, normal echocardiography and CMR LVEF, and no LGE. CONCLUSION: native T1 mapping detects left ventricular ET1 (potential DMF) in 50% of patients with SSc and a third of them had a normal conventional screening including standard CMR. In the future, further studies are needed to confirm the benefit of use of native T1 mapping as a part of routine follow up to detect earlier pejorative cardiac involvement in SSc patients.

320-row CT transcatheter aortic valve replacement planning with a single reduced contrast media bolus injection.

OBJECTIVE: To reduce the iodine load required for CT Transcatheter Aortic Valve Replacement (TAVR) planning on a 320-row scanner by acquiring the two CT TAVR steps (ECG-gated aortic root CTA and non-gated aorto-ilio-femoral CTA) within a single contrast media bolus injection. METHODS: 50 consecutive patients (82.6±6.9 years; 56% female) were prospectively enrolled and underwent a TAVR planning using a 320-row CT, with ECG-gated aortic root CTA immediately followed by a non-gated aorto-iliac acquisition, all within a single bolus of 40-70mL of Iohexol 350mgI/mL. The Iodine load, image quality, SNR, CNR and radiation dose were compared using a Mann-Whitney test to that of 24 consecutive patients (84.3±4.8 years, 58% female) previously imaged on a 64-row scanner with a conventional two-step protocol. RESULTS: Iodine load was reduced by 44%. All examinations were of diagnostic quality, with improvement of the aortic root CTA image quality (4.9±0.3 versus 4.6±0.5, p<0.01) and a non-significant decrease of the aorto-iliac CTA image quality (4.7±0.6 versus 4.9±0.3, p = 0.07). SNR and CNR were significantly improved in the aortic root CTA (14.0±5.3 and 10.4±4.5 versus 10.3±4.2 and 6.8±3.3, p<0.01 for both) and non-significantly higher in the aorto-iliac CTA (16.5±8.0 and 14.1±7.9 versus 14.7±5.5 and 12.5±5.0, p = 0.42 and p = 0.66). Total radiation dose was reduced by 32%. CONCLUSION: 320-row CT scanner enables a 44% reduction of iodine load in TAVR planning, while maintaining excellent aorto-ilio-femoral arterial enhancement and lowering radiation dose.

A dual flip angle 3D bSSFP magnetization transfer-like method to differentiate between recent and old myocardial infarction.

BACKGROUND: Magnetic resonance imaging (MRI) tissue signal is modulated by magnetization transfer (MT) phenomena, intrinsically induced by balanced steady-state free precession (bSSFP) imaging. PURPOSE: To investigate the possible value of such a MT-like bSSFP approach in two clinical settings involving focal myocardial lesions highligthed by late gadolinium enhancement (LGE+): edema induced by recent myocardial infarction (MI) and fibrotic scar related to chronic infarction. MATERIALS AND METHODS: Population: 48 LGE + patients were studied: 26 with recent MI, 22 with chronic MI. 20 LGE-normal subjects were considered the control group. Field strength/sequence: Navigator-based short axis 3D-bSSFP sequences with 20° and 90° excitation flip angles were acquired (1.5T). ASSESSMENT: Pixel-wise normalized MT Ratio (nMTR) parametric images were calculated according to: nMTR = 100*(S20 -S90 *k)/S20 , with S20 and S90 signal intensity in 20° and 90° flip angle images and k = Blood20 /Blood90 as a normalization ratio. Statistical tests: analysis of variance (ANOVA), receiver operating characteristic (ROC) analysis. RESULTS: Overall normal myocardial nMTR was 50.2 ± 3.6%. In recent MI, nMTR values were significantly reduced in LGE + regions (-22.3 ± 9.9%, P < 0.0001). In cases of chronic infarct, nMTR was significantly increased in LGE + regions (14.2 ± 11.4%, P < 0.0001). Comparison between observed results and theoretical values obtained with the Freeman-Hill formula showed that most variations observed in MI are related to MT effects instead of relaxation effects. CONCLUSION: In contrast to LGE imaging, which may show a similar hyperenhancement in recent and old infarctions, nMTR imaging demonstrates an opposite pattern: decreased values for recent infarction and increased values for old infarction, thus allowing to discriminate between these two clinical conditions without gadolinium injection. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:798-808.

Late Detection of Left Ventricular Dysfunction Using Two-Dimensional and Three-Dimensional Speckle-Tracking Echocardiography in Patients with History of Nonsevere Acute Myocarditis.

BACKGROUND: Acute myocarditis (AM) often involves the left ventricular (LV) subepicardium that might be displayed by cardiac magnetic resonance even late after the acute phase. In the absence of global or regional LV dysfunction, conventional transthoracic echocardiography (TTE) does not accurately identify tissue sequelae of AM. We sought to evaluate the diagnostic value of two-dimensional (2D) and three-dimensional (3D) speckle-tracking echocardiography to identify patients with a history of AM with preserved LV ejection fraction (LVEF). METHODS: Fifty patients (group 1: age, 31.4 ± 10.5 years; 76% males) with a history of cardiac magnetic resonance-confirmed diagnosis of AM (according to the Lake Louise criteria) were retrospectively identified and then (21.7 ± 23.4 months later) evaluated by complete echocardiography including 2D and 3D speckle-tracking analysis, as well as 50 age- and gender-matched healthy controls (group 2: age, 31.2 ± 9.5 years: 76% males). Patients with a history of severe clinical presentation of AM (sudden death, ventricular arrhythmia, heart failure, alteration of LVEF) were excluded. RESULTS: At diagnosis, peak troponin and C-reactive protein were 11.97 (interquartile range, 4.52-25.92) µg/L and 32.3 (interquartile range, 14.85-70.45) mg/L, respectively. Mean delay between acute phase and follow-up study TTE was 21.7 ± 23.4 months. LVEF was not statistically different between groups (62.1% vs 63.5%, P = .099). Two-dimensional global longitudinal strain (GLS) was lower in magnitude in group 1 (-17.8% vs -22.1%, P < .0001) as were 2D layer-specific subepicardial GLS (-15.4% vs -19.7%, P < .0001) and subendocardial GLS (-20.71% vs -25.08%, P < .0001). Three-dimensional global longitudinal, circumferential, area, and radial strains were lower in magnitude in group 1 (-11.80% vs -14.98%, P < .0001; -12.57% vs -15.12%, P < .0001; -22.28% vs -25.87%, P < .0001; 31.47% vs 38.06%, P < .0001, respectively). Receiver operating characteristic curve analysis showed that subepicardial GLS displayed a better diagnostic performance to detect sequelae of AM as compared with GLS (area under the curve = 0.97 vs 0.93, P = .045). CONCLUSIONS: In patients with a history of AM, a subtle LV dysfunction can be detected by 2D and 3D speckle-tracking echocardiography, even though LVEF is conserved, adding incremental information over conventional TTE.

Longitudinal 2D strain can help diagnose coronary artery disease in patients with suspected non-ST-elevation acute coronary syndrome but apparent normal global and segmental systolic function.

BACKGROUND: The clinical work-up of patients presenting with chest pain is a diagnostic challenge. We investigated the diagnostic performance of global (GLS) and territorial (TLS) longitudinal strain to predict coronary artery disease (CAD) in patients presenting with suspected non-ST-segment elevation acute coronary syndrome (NSTE-ACS) but apparent normal global and regional systolic function. METHODS: 150 consecutive suspected NSTE-ACS patients were initially screened for inclusion ; 58 patients with normal LVEF (≥55%) and WMSI (=1) were prospectively enrolled. Speckle-tracking echocardiography was performed on admission and all the patients underwent coronary angiography. CAD was defined as the presence of stenosis of >50%. RESULTS: CAD was present in 33 patients (57%). LVEF was 60.7±4.6% in group 1 (CAD) and 61.1±5.0% in group 2 (no CAD). Global longitudinal strain (GLS) was altered in group 1 (-16.7±3.4%) as compared to group 2 (-22.4±2.9%, p<0.001). ROC curve analysis showed a high diagnostic value of GLS for the prediction of CAD (AUC=0.92 [0.84-1.00], p=0.0001). TLS was able to discriminate between coronary stenosis in the LAD, LCX or RCA. CONCLUSIONS: Longitudinal 2D strain has a good diagnostic value and can efficiently localize the culprit lesion in patients presenting with NSTE-ACS but apparent normal global and regional systolic function.

Magnetic resonance evaluation of cardiac thrombi and masses by T1 and T2 mapping: an observational study.

The purpose of this work was to evaluate CMR T1 and T2 mapping sequences in patients with intracardiac thrombi and masses in order to assess T1 and T2 relaxometry usefulness and to allow better etiological diagnosis. This observational study of patients scheduled for routine CMR was performed from September 2014 to August 2015. All patients referred to our department for a 1.5 T CMR were screened to participate. T1 mapping were acquired before and after Gadolinium injection; T2 mapping images were obtained before injection. 41 patients were included. 22 presented with cardiac thrombi and 19 with cardiac masses. The native T1 of thrombi was 1037 ± 152 ms (vs 1032 ± 39 ms for myocardium, p = 0.88; vs 1565 ± 88 ms for blood pool, p < 0.0001). T2 were 74 ± 13 ms (vs 51 ± 3 ms for myocardium, p < 0.0001; vs 170 ± 32 ms for blood pool, p < 0.0001). Recent thrombi had a native T1 shorter than old thrombi (911 ± 177 vs 1169 ± 107 ms, p = 0.01). The masses having a shorter T1 than the myocardium were lipomas (278 ± 29 ms), calcifications (621 ± 218 ms), and melanoma (736 ms). All other masses showed T1 values higher than myocardial T1, with T2 consistently >70 ms. T1 and T2 mapping CMR sequences can be useful and represent a new approach for the evaluation of cardiac thrombi and masses.