Conventional Cardiac Magnetic Resonance Research Articles

High-Resolution Late Gadolinium Enhancement Magnetic Resonance for the Diagnosis of Myocardial Infarction With Nonobstructed Coronary Arteries

ObjectivesThe aim of this study was to assess the diagnostic yield of cardiac magnetic resonance (CMR) including high-resolution (HR) late gadolinium enhancement (LGE) imaging using a 3-dimensional respiratory-navigated method in patients with myocardial infarction with nonobstructed coronary arteries (MINOCA). BackgroundCMR plays a pivotal role for the diagnosis of patients with MINOCA. However, the diagnosis remains inconclusive in a significant number of patients, the results of CMR being either negative or uncertain (i.e., compatible with multiple diagnoses). MethodsConsecutive patients categorized as having MINOCA after blood testing, electrocardiography, coronary angiography, and echocardiography underwent conventional CMR, including cine, T2-weighted, first-pass perfusion, and conventional breath-held LGE imaging. HR LGE imaging using a free-breathing method allowing improved spatial resolution (voxel size 1.25 × 1.25 × 2.5 mm) was added to the protocol when the results of conventional CMR were inconclusive and was optional otherwise. Diagnoses retained after reviewing conventional CMR were compared with those retained after the addition of HR LGE imaging. ResultsFrom 2013 to 2016, 229 patients were included (mean age 56 ± 17 years, 45% women). HR LGE imaging was performed in 172 patients (75%). In this subpopulation, definite diagnoses were retained after conventional CMR in 86 patients (50%): infarction in 39 (23%), myocarditis in 32 (19%), takotsubo cardiomyopathy in 13 (8%), and other diagnoses in 2 (1%). In the remaining 86 patients (50%), results of CMR were inconclusive: negative in 54 (31%) and consistent with multiple diagnoses in 32 (19%). HR LGE imaging led to changes in final diagnosis in 45 patients (26%) and to a lower rate of inconclusive final diagnosis (29%) (p < 0.001). In particular, HR LGE imaging could reveal or ascertain the diagnosis of infarction in 14% and rule out the diagnosis of infarction in 12%. HR LGE imaging was particularly useful when the results of transthoracic echocardiography, ventriculography, and conventional CMR were negative, with a 48% rate of modified diagnosis in this subpopulation. ConclusionsHR LGE imaging has high diagnostic value in patients with MINOCA and inconclusive findings on conventional CMR. This has major diagnostic, prognostic, and therapeutic implications.

P363 Cardiac magnetic resonance characteristics of patients in the grey zone of hypertrophy

Abstract Funding Acknowledgements National Research, Development and Innovation Office (NKFIH) of Hungary (K 120277); Project no. NVKP_16-1-2016-0017. Supported by the ÚNKP-18-3-IV Background Differentiation between athlete’s heart and hypertrophic cardiomyopathy (HCM) may cause difficulties especially in patients in the grey zone of hypertrophy. Purpose We aimed to analyse cardiac magnetic resonance (CMR) characteristics of healthy athletes, sedentary HCM and athletic HCM patients in the grey zone of hypertrophy. Methods Male HCM patients with slightly elevated maximal end-diastolic wall thickness (EDWT 13-18 mm) and highly trained healthy athletes (n = 34, 20.4 ± 2.3 training hrs/week) were consecutively enrolled. HCM patient group was divided to sedentary (n = 35, &amp;lt;7 training hrs/week) and athletic HCM group (n = 13; &amp;gt;7 h/week, 13.2 ± 5.0 h training hrs/week).We determined conventional CMR parameters (left ventricular (LV) ejection fraction (EF),BSA-corrected end-diastolic (EDVi) and end-systolic volume (ESVi), mass (Mi)), derived parameters such as EDWT/LVEDVi, LVM/LVEDV and CMR based strain parameters such as global longitudinal (GLS), radial (GRS) and circumferential strain (GCS), standard deviation of peak LS, RS and CS (SD LS peak, SD RS peak, SD CS peak), standard deviation of time to peak LS, RS and CS (TTP LS, TTP RS, TTP CS) using feature tracking. Presence of late gadolinium enhancement (LGE) was determined on delayed contrast enhanced images. Inter-observer analysis for strain values was performed in a subgroup of 20 patients conducted by two blinded observer. Results Healthy athletes showed lower LVEF, GCS and GRS than sedentary and athletic HCM patients, respectively (57.9 ± 5.2 vs 65.3 ± 7.4, 62.7 ± 5.1; -19.7 ± 7.0 vs -24.4 ± 4.6, -22.8 ± 4.8; 61.7 ± 11.2 vs 75.4 ± 21.4, 69.3 ± 19.8). Both healthy athletes and athletes with HCM showed higher LVEDVi, LVESVi, LVSVi and LVMi than sedentary HCM patients. Although sedentary athletes showed higher SD peak strain values and more pronounced intraventricular dyssynchrony than healthy athletes (TTP LS 15.4 ± 4.9 vs 11.7 ± 4.3), none of the global strain values, SD of peak strain values or TTP strain values showed any difference between athletic HCM and healthy athletes. EDWT/LVEDVi ratio was significantly lower in healthy athletes than in sedentary and athletic HCM, respectively (0.11 ± 0.02 vs 0.19±.0.04; 0.18 ± 0.04). Inter-observer analysis showed good agreement in GLS (κ=0.77), GRS (κ=0.69) and TTP LS (κ=0.74), moderate agreement in GCS (κ=0.54), and only fair or poor agreement in SD peak strain, TTP CS and TTP RS values. None of the healthy athletes showed LGE, 62% of athletic HCM and 71% of sedentary HCM patients showed LGE in the hypertrophic segments or in the insertion points. Conclusions Based on our results CMR characteristics of sedentary and athletic HCM differs significantly, therefore establishing diagnostic parameters and cut-off values based on comparison between athletic HCM and healthy athletes would be essential. Presence of late gadolinium enhancement and derived parameters may have an important role in the differential diagnosis.

Biventricular pacing during cardiac magnetic resonance imaging.

We aimed to assess the effect of cardiac resynchronization on left ventricular (LV) function, volumes, geometry, and mechanics in order to demonstrate reverse remodelling using cardiac magnetic resonance (CMR) with resynchronization on. New York Heart Association (NYHA) Class II-III patients on optimal medical therapy with LV ejection fraction (LVEF) ≤35%, and complete LBBB with broad QRS (>150 ms) were prospectively recruited. Cardiac magnetic resonance examination was performed at baseline and at 6-month follow-up, applying both biventricular and AOO pacing. The following data were measured: conventional CMR parameters, remodelling indices, global longitudinal, circumferential, radial strain, global dyssynchrony [mechanical dispersion (MD) defined as the standard deviation of time to peak longitudinal/circumferential strain in 16 LV segments], and regional dyssynchrony (maximum differences in time between peak septal and lateral transversal displacement). Thirteen patients (64 ± 7 years, 38% male) were enrolled. Comparing the baseline and follow-up CMR parameters measured during biventricular pacing, significant increase in LVEF, and decrease in LV end-diastolic volume index (LVEDVi) and LV end-systolic volume index (LVESVi) were found. Left ventricular remodelling indices, global longitudinal, circumferential, and radial strain values showed significant improvement. Circumferential MD decreased (20.5 ± 5.5 vs. 13.4 ± 3.4, P < 0.001), while longitudinal MD did not change. Regional dyssynchrony drastically improved (362 ± 96 vs. 104 ± 66 ms, P < 0.001). Applying AOO pacing resulted in an immediate deterioration in LVEF, LVESVi, circumferential strain, global and regional dyssynchrony. Cardiac magnetic resonance imaging during biventricular pacing is feasible and enables a more precise quantification of LV function, morphology, and mechanics. As a result, it may contribute to a better understanding of the effects of resynchronization therapy and might improve responder rate in the future.

P4429Cardiac magnetic resonance characteristics of professional athletes and hypertrophic cardiomyopathy patients in the grey zone of hypertrophy

Abstract Differentiation between athlete's heart and hypertrophic cardiomyopathy (HCM) may cause difficulties especially in patients in the grey zone of hypertrophy. We aimed to determine conventional cardiac magnetic resonance (CMR) parameters such as left ventricular (LV) ejection fraction (EF), BSA-corrected end-diastolic (EDVi), end-systolic and stroke volume (SVi), mass (Mi), derived CMR parameters such as maximal end-diastolic wall thickness to LVEDVi ratio (EDWT/LVEDVi), LVM to LVEDV ratio (LVM/LVEDV), and CMR based strain values (global longitudinal (GLS), radial (GRS) and circumferential strain (GCS)) in male HCM patients and athletes. We consecutively enrolled male HCM patients with only slightly elevated EDWT (13–18 mm) and highly trained healthy athletes (n=30, 18.7±1.2 training hrs/week) with marked LV hypertrophy. HCM patient group was divided into sedentary (n=30, &lt;7 training hrs/week) and athletic HCM group (n=10; &gt;7 h/week, 12.7±7.3 h training hrs/week). Both sedentary and athletic HCM patients showed higher LVEF, lower LVEDVi and LVESVi and higher EDWT compared to the healthy athletes. LVMi of both healthy athletes and athletic HCM patients was significantly higher than in sedentary HCM patients, respectively (98.9±11.4; 94.5±7.8 vs 78.1±14.4 /m2). EDWT/LVEDVi ratio was higher in both sedentary and athletic HCM patients compared to healthy athletes, respectively (0.19±0.04; 0.17±0.04 vs 0.11±0.02). LVM/LVEDV also showed significant difference between HCM patients and healthy athletes. GLS and GRS showed no significant difference between the three groups, GCS was higher in athletic HCM compared to healthy athletes (−20.7±2.2 vs −17.8±2.3%). Figure 1. Feature tracking analysis of a healthy athlete and a patient with HCM. CMR characteristics of athletic and sedentary HCM may fundamentally alter. Our preliminary data suggest that besides conventional CMR parameters, derived parameters such as EDWT/LVEDVi and LVM/LVEDV ratios and deformation imaging may also help the differentiation between pathological and physiological hypertrophy. Acknowledgement/Funding National Research, Development and Innovation Office (NKFIH) of Hungary (K 120277). Project no. NVKP_16-1-2016-0017

Cardiac Magnetic Resonance for the Evaluation of Suspected Cardiac Thrombus: Conventional and Emerging Techniques

We present the conventional cardiac magnetic resonance (CMR) protocol for evaluating a suspected thrombus and highlight emerging techniques.The appearance of a mass on certain magnetic resonance (MR) sequences can help differentiate a thrombus from competing diagnoses such as a tumor. T1 and T2 signal characteristics of a thrombus are related to the evolution of hemoglobin properties. A thrombus typically does not enhance following contrast administration, which also helps differentiation from a tumor. We also highlight the emerging role of T1 mapping in the evaluation of a thrombus, which can add another level of support in diagnosis. Prior to any CMR exam, patient screening and interviews are critical to ensure safety and to optimize patient comfort. Effective communication during the exam between the technologist and the patient promotes proper breath holding technique and higher quality images. Volumetric post processing and structured reporting are helpful to ensure that the radiologist answers the ordering services' question and communicates these results effectively. Optimal pre-MR safety evaluation, CMR exam execution, and post exam processing and reporting allow for delivery of high quality radiological service in the evaluation of a suspected cardiac thrombus.

Substrate-dependent risk stratification for implantable cardioverter defibrillator therapies using cardiac magnetic resonance imaging: The importance of T1 mapping in nonischemic patients.

The role of implantable cardioverter defibrillators (ICDs) in nonischemic cardiomyopathy is unclear and better risk-stratification is required. We sought to determine if T1 mapping predicts appropriate defibrillator therapy in patients with nonischemic cardiomyopathy. We studied a mixed cohort of ischemic and nonischemic patients to determine whether different cardiac magnetic resonance (CMR) applications (T1 mapping, late gadolinium enhancement, and Grayzone) were selectively predictive of therapies for the different arrhythmic substrates. We undertook a prospective longitudinal study of consecutive patients receiving defibrillators in a tertiary cardiac center. Participants underwent CMR myocardial tissue characterization using T1 mapping and conventional CMR scar assessment before device implantation. QRS duration and fragmentation on the surface electrocardiogram were also assessed. The primary endpoint was appropriate defibrillator therapy. One-hundred thirty patients were followed up for a median of 31 months (IQR ± 9 months). In nonischemic patients, T1_native was the sole predictor of the primary endpoint (hazard ratio [HR] 1.12 per 10 millisecond increment in value [95% confidence interval [CI] 1.04-1.21; P ≤ 0.01]). In ischemic patients, Grayzone_2SD-3SD was the strongest predictor of appropriate therapy (HR 1.34 per 1% left ventricular increment in value [95% CI 1.03-1.76; P = 0.03]). QRS fragmentation correlated well with myocardial scar core (receiver operating characteristic area under the curve [ROC AUC] 0.64; P = 0.02) but poorly with T1_native (ROC AUC 0.4) and did not predict appropriate therapy. In the medium-long term, T1_native mapping was the only independent predictor of therapy in nonischemic patients, whereas Grayzone was a better predictor in ischemic patients. These findings suggest a potential role for T1_native mapping in the selection of patients for ICDs in a nonischemic population.

82 Relationship between cardiac structure and functional capacity in a fontan cohort

IntroductionFollow up of Fontan patients involves a multimodality approach including imaging to assess cardiac function and cardiopulmonary exercise testing (CPET) to assess functional capacity. Decision making, including use of device...

Complementary Role of CMR to Conventional Screening in the Diagnosis and Prognosis of Cardiac Sarcoidosis

ObjectivesThe goal of this study was to assess the independent and collective diagnostic value of various modalities in cardiac sarcoidosis, delineate the role of cardiac magnetic resonance (CMR), and identify patients at risk. BackgroundCardiac sarcoidosis is associated with increased morbidity and mortality. CMR is a key modality in the evaluation of patients with cardiac symptoms, but the complementary role of CMR to conventional tests for the diagnosis of cardiac sarcoidosis is not fully defined. MethodsPatients (N = 321) with biopsy-proven sarcoidosis underwent conventional cardiac testing and CMR with late gadolinium enhancement (LGE) and were followed up for primary (composite of all-cause mortality, sustained ventricular tachycardia [VT] episodes, or hospitalization for heart failure) and secondary (nonsustained VT episodes) endpoints. ResultsCardiac sarcoidosis was diagnosed in 29.9% of patients according to the Heart Rhythm Society consensus criteria. CMR was the most sensitive and specific test (area under the curve: 0.984); it detected 44 patients with cardiac symptoms and/or electrocardiogram (ECG) abnormalities but normal echocardiogram, as well as 15 asymptomatic patients with normal baseline testing. Echocardiography added to cardiac history and ECG did not change sensitivity of the initial screening strategy (68.8% vs. 72.9%). Despite a high positive predictive value (83.9%), echocardiography had a low sensitivity (27.1%). During follow-up, 7.2% of patients reached the primary endpoint and another 3.4% reached the secondary endpoint. LGE was and independent predictor of primary endpoints (hazard ratio: 5.68; 95% CI: 1.74 to 18.49; p = 0.004). LGE, age, and baseline nonsustained VT were independent predictors of all events. In patients with cardiac symptoms and/or an abnormal ECG, CMR increased diagnostic accuracy and independently predicted primary endpoints (hazard ratio: 12.71; 95% confidence interval: 1.48 to 109.35; p = 0.021). ConclusionsOf all cardiac tests, CMR was the most valuable in the diagnosis and prognosis of cardiac sarcoidosis in a general sarcoidosis population. Echocardiography had an overall limited diagnostic value as a screening test, and an abnormal study, despite a high positive predictive value, may still need confirmation with CMR.

Native Myocardial T1 Mapping, Are We There Yet?

T1 or longitudinal relaxation time is one of the very fundamental magnetic resonance imaging (MRI) time constants and a tissue characterizing parameter. Only during the last decade did it become possible to quantify T1 values of the myocardium through T1 mapping. Evolving from only region of interest analysis and long acquisition times to the pixel-based parametric mapping and short breath-hold sequences, T1 mapping is reaching maturity among cardiac magnetic resonance (CMR) techniques. Both inversion recovery methods such as MOdified Look-Locker Inversion (MOL-LI) and Shortened MOLLI (ShMOLLI) and saturation recovery methods such as Saturation recovery Single-Shot Acquisition (SASHA) are available for T1 quantification with variable degrees of accuracy, precision, and reproducibility. Native (non-contrast) T1 values increase with edema, amyloid deposition, and fibrosis, while they decrease in fat or iron deposition in the myocardium. These features enabled significant expansion of the clinical applications of native T1 mapping where it provides high sensitivity and specificity and even acts as a disease biomarker or a predictor of prognosis. It is of particular usefulness in diffuse myocardial diseases where conventional CMR techniques might be deceiving. A brighter future for the technique is expected if certain challenges are to be faced, examples of which are the need for standardization of normal values, acquisition techniques, and improving analysis tools.

Adenosine Stress and Rest T1 Mapping Can Differentiate Between Ischemic, Infarcted, Remote, and Normal Myocardium Without the Need for Gadolinium Contrast Agents

ObjectivesThe aim of this study was to evaluate the potential of T1 mapping at rest and during adenosine stress as a novel method for ischemia detection without the use of gadolinium contrast. BackgroundIn chronic coronary artery disease (CAD), accurate detection of ischemia is important because targeted revascularization improves clinical outcomes. Myocardial blood volume (MBV) may be a more comprehensive marker of ischemia than myocardial blood flow. T1 mapping using cardiac magnetic resonance (CMR) is highly sensitive to changes in myocardial water content, including MBV. We propose that T1 mapping at rest and during adenosine vasodilatory stress can detect MBV changes in normal and diseased myocardium in CAD. MethodsTwenty normal controls (10 at 1.5-T; 10 at 3.0-T) and 10 CAD patients (1.5-T) underwent conventional CMR to assess for left ventricular function (cine), infarction (late gadolinium enhancement [LGE]) and ischemia (myocardial perfusion reserve index [MPRI] on first-pass perfusion imaging during adenosine stress). These were compared to novel pre-contrast stress/rest T1 mapping using the Shortened Modified Look-Locker Inversion recovery technique, which is heart rate independent. T1 values were derived for normal myocardium in controls and for infarcted, ischemic, and remote myocardium in CAD patients. ResultsNormal myocardium in controls (normal wall motion, MPRI, no LGE) showed normal resting T1 (954 ± 19 ms at 1.5-T; 1,189 ± 34 ms at 3.0-T) and significant positive T1 reactivity during adenosine stress compared to baseline (6.2 ± 0.5% at 1.5-T; 6.3 ± 1.1% at 3.0-T; all p < 0.0001). Infarcted myocardium showed the highest resting T1 of all tissue classes (1,442 ± 84 ms), without significant T1 reactivity (0.2 ± 1.5%). Ischemic myocardium showed elevated resting T1 compared to normal (987 ± 17 ms; p < 0.001) without significant T1 reactivity (0.2 ± 0.8%). Remote myocardium, although having comparable resting T1 to normal (955 ± 17 ms; p = 0.92), showed blunted T1 reactivity (3.9 ± 0.6%; p < 0.001). ConclusionsT1 mapping at rest and during adenosine stress can differentiate between normal, infarcted, ischemic, and remote myocardium with distinctive T1 profiles. Stress/rest T1 mapping holds promise for ischemia detection without the need for gadolinium contrast.

Lights and shadows of cardiac magnetic resonance imaging in acute myocarditis.

Cardiac magnetic resonance (CMR) is considered a primary tool for the diagnosis of acute myocarditis, due to its unique potential for non-invasive identification of the various hallmarks of the inflammatory response, with relevant impact on patient management and prognosis. Nonetheless, a marked variation in sensitivity and negative predictive value has been reported in the literature, reflecting the intrinsic drawbacks of current diagnostic criteria, which are based mainly on the use of conventional CMR pulse sequences. As a consequence, a negative exam cannot reliably exclude the diagnosis, especially in patients who do not present an infarct-like onset of disease. The introduction of new-generation mapping techniques further widened CMR potentials, allowing quantification of tissue changes and opening new avenues for non-invasive workup of patients with inflammatory myocardial disease.Main messages• CMR sensitivity varies in AM, reflecting its clinical polymorphism and the intrinsic drawbacks of LLc.• Semiquantitative approaches such as EGEr or T2 ratio have limited accuracy in diffuse disease forms.• T1 mapping allows objective quantification of inflammation, with no need to normalize measurements.• A revised protocol including T2-STIR, T1 mapping and LGE could be hypothesized to improve sensitivity.

Right Ventricular Strain and Dyssynchrony Assessment in Arrhythmogenic Right Ventricular Cardiomyopathy: Cardiac Magnetic Resonance Feature-Tracking Study.

Analysis of right ventricular (RV) regional dysfunction by cardiac magnetic resonance (CMR) imaging in arrhythmogenic RV cardiomyopathy (ARVC) may be inadequate because of the complex contraction pattern of the RV. Aim of this study was to determine the use of RV strain and dyssynchrony assessment in ARVC using feature-tracking CMR analysis. Thirty-two consecutive patients with ARVC referred to CMR imaging were included. Thirty-two patients with idiopathic RV outflow tract arrhythmias and 32 control subjects, matched for age and sex to the ARVC group, were included for comparison purpose. CMR imaging was performed to assess biventricular function; feature-tracking analysis was applied to the cine CMR images to assess regional and global longitudinal, circumferential, and radial RV strains and RV dyssynchrony (defined as the SD of the time-to-peak strain of the RV segments). RV global longitudinal strain (-17±5% versus -26±6% versus -29±6%; P<0.001), global circumferential strain (-9±4% versus -12±4% versus -13±5%; P=0.001), and global radial strain (18 [12-26]% versus 22 [15-32]% versus 27 [20-39]%; P=0.015) were significantly lower and SD of the time-to-peak RV strain in all 3 directions were significantly higher among patients with ARVC compared with patients with RV outflow tract arrhythmias and controls. RV global longitudinal strain >-23.2%, SD of the time-to-peak RV longitudinal strain >113.1 ms, and SD of the time-to-peak RV circumferential strain >177.1 ms allowed correct identification of 88%, 75%, and 63% of ARVC patients with no or only minor CMR criteria for ARVC diagnosis. Strain analysis by feature-tracking CMR helps to objectively quantify global and regional RV dysfunction and RV dyssynchrony in patients with ARVC and provides incremental value over conventional cine CMR imaging.

Iron-Sensitive Cardiac Magnetic Resonance Imaging for Prediction of Ventricular Arrhythmia Risk in Patients With Chronic Myocardial Infarction: Early Evidence.

Recent canines studies have shown that iron deposition within chronic myocardial infarction (CMI) influences the electric behavior of the heart. To date, the link between the iron deposition and malignant ventricular arrhythmias in humans with CMI is unknown. Patients with CMI (n=94) who underwent late-gadolinium-enhanced cardiac magnetic resonance imaging before implantable cardioverter-defibrillator implantation for primary and secondary preventions were retrospectively analyzed. The predictive values of hypointense cores (HIC) in balanced steady-state free precession images and conventional cardiac magnetic resonance imaging and ECG malignant ventricular arrhythmia parameters for the prediction of primary combined outcome (appropriate implantable cardioverter-defibrillator therapy, survived cardiac arrest, or sudden cardiac death) were studied. The use of HIC within CMI on balanced steady-state free precession as a marker of iron deposition was validated in a canine MI model (n=18). Nineteen patients met the study criteria with events occurring at a median of 249 (interquartile range of 540) days after implantable cardioverter-defibrillator placement. Of the 19 patients meeting the primary end point, 18 were classified as HIC+, whereas only 1 was HIC-. Among the cohort in whom the primary end point was not met, there were 28 HIC+ and 47 HIC- patients. Receiver operating characteristic curve analysis demonstrated an additive predictive value of HIC for malignant ventricular arrhythmias with an increased area under the curve of 0.87 when added to left ventricular ejection fraction (left ventricular ejection fraction alone, 0.68). Both cardiac magnetic resonance imaging and histological validation studies performed in canines demonstrated that HIC regions in balanced steady-state free precession images within CMI likely result from iron depositions. Hypointense cores within CMI on balanced steady-state free precession cardiac magnetic resonance imaging can be used as a marker of iron deposition and yields incremental information toward improved prediction of malignant ventricular arrhythmias.

Initial experience with a cardiac multi-contrast real-time cine prototype integrating sparse sampling and iterative reconstruction

Methods All patients were submitted to a conventional cardiac magnetic resonance study (Magnetom Aera, Siemens AG Healthcare, Germany) that included shortand long-axis steady-state free-precession (SSFP) segmented cine measurements (spatial resol.: 1.5x1.5 mm; slice thickness: 7 mm; temporal resol.: 40 ms; 7 heart beats (HB)/slice), modified Look-Locker inversion recovery post-contrast T1 mapping (spatial resol.: 1.6x1.6 mm; slice thickness: 8 mm; 17 HB/slice), and segmented spoiled gradient-echo late gadolinium enhancement (LGE) images (spatial resol.: 1.6x1.6 mm; slice thickness: 8 mm; 8-10 HB/slice). Followed by multi-TI real-time cine performed in the same cardiac planes (spatial resol.: 2.1x2.1 mm; slice thickness: 8 mm; temporal resol.: 45 ms; 4 HB/slice). The multi-TI cine prototype has been described in detail elsewhere, but briefly it consists of an inversion recovery highly accelerated SSFP 2D real-time cine sequence, featuring sparse sampling and k-t regularization. Using an offline reconstruction algorithm based on a registration and motion-propagation strategy, a full-length cine can be reconstructed for each acquired TI (fig. 1) and also a pseudo-T1 map cine. Results A total of 12 consecutive patients (61% male, 50±19 yrs) were included. All sequences were successfully performed and reconstructed, rendering good-quality images on subjective analysis. In all patients, a multi-TI cine, with ideal myocardial nulling, could be produced for simultaneous cardiac function and LGE analysis. Figure 2 illustrates a case of myocardial infarction with evident apical fibrosis on LGE and post-contrast T1 map, associated with akinesia of the involved segments on standard cines. On multi-TI cine, both abnormalities could be fully appreciated. In a subject with myocarditis, subtle mesocardial LGE without segmental contractility dysfunction was also adequately depicted on multi-TI cines (fig. 1). Conventional cine and LGE together required more time and breath-holds than multi-TI cines (745±210 seconds and 13±1 BH vs. 357±39 seconds and 3±0 BH respectively).

Ventricular kinetic energy may provide a novel noninvasive way to assess ventricular performance in patients with repaired tetralogy of Fallot

ObjectiveVentricular kinetic energy measurements may provide a novel imaging biomarker of declining ventricular efficiency in patients with repaired tetralogy of Fallot. Our purpose was to assess differences in ventricular kinetic energy with 4-dimensional flow magnetic resonance imaging between patients with repaired tetralogy of Fallot and healthy volunteers. MethodsCardiac magnetic resonance, including 4-dimensional flow magnetic resonance imaging, was performed at rest in 10 subjects with repaired tetralogy of Fallot and 9 healthy volunteers using clinical 1.5T and 3T magnetic resonance imaging scanners. Right and left ventricular kinetic energy (KERV and KELV), main pulmonary artery flow (QMPA), and aortic flow (QAO) were quantified using 4-dimensional flow magnetic resonance imaging data. Right and left ventricular size and function were measured using standard cardiac magnetic resonance techniques. Differences in peak systolic KERV and KELV in addition to the QMPA/KERV and QAO/KELV ratios between groups were assessed. Kinetic energy indices were compared with conventional cardiac magnetic resonance parameters. ResultsPeak systolic KERV and KELV were higher in patients with repaired tetralogy of Fallot (6.06 ± 2.27 mJ and 3.55 ± 2.12 mJ, respectively) than in healthy volunteers (5.47 ± 2.52 mJ and 2.48 ± 0.75 mJ, respectively), but were not statistically significant (P = .65 and P = .47, respectively). The QMPA/KERV and QAO/KELV ratios were lower in patients with repaired tetralogy of Fallot (7.53 ± 5.37 mL/[cycle mJ] and 9.65 ± 6.61 mL/[cycle mJ], respectively) than in healthy volunteers (19.33 ± 18.52 mL/[cycle mJ] and 35.98 ± 7.66 mL/[cycle mJ], respectively; P < .05). QMPA/KERV and QAO/KELV were weakly correlated to ventricular size and function. ConclusionsGreater ventricular kinetic energy is necessary to generate flow in the pulmonary and aortic circulations in repaired tetralogy of Fallot. Quantification of ventricular kinetic energy in patients with repaired tetralogy of Fallot is a new observation. Future studies are needed to determine whether changes in ventricular kinetic energy can provide earlier evidence of ventricular dysfunction and guide future medical and surgical interventions.

CMR in Patients With Severe Myocarditis: Diagnostic Value of Quantitative Tissue Markers Including Extracellular Volume Imaging

ObjectivesThis study evaluated the accuracy of T2, T1, and extracellular volume (ECV) quantification as novel quantitative tissue markers in comparison with standard “Lake-Louise” cardiac magnetic resonance (CMR) criteria to diagnose myocarditis. BackgroundNovel approaches using T2 and T1 mapping may overcome the limitations of signal intensity-based parameters, which would potentially result in a better diagnostic accuracy compared with standard CMR techniques in suspected myocarditis. MethodsCMR was performed in 104 patients with myocarditis and 21 control subjects at 1.5-T. Patients with myocarditis underwent CMR 2 weeks (interquartile range: 1 to 7 weeks) after presentation with new-onset heart failure (n = 66) or acute chest pain (n = 38). T2 and T1 mapping were implemented into a standard protocol including T2-weighted (T2w), early gadolinium enhancement (EGE) CMR, and late gadolinium enhancement (LGE) CMR. T2 quantification was performed using a free-breathing, navigator-gated multiecho sequence. T1 quantification was performed using the modified Look-Locker inversion recovery sequence before and after administration of 0.075 mmol/kg gadobenate dimeglumine. T2, T1, and ECV maps were generated using a plug-in for the OsiriX software (Pixmeo, Bernex, Switzerland) to calculate mean global myocardial T2, T1, and ECV values. ResultsThe diagnostic accuracies of conventional CMR were 70% (95% confidence interval [CI]: 61% to 77%) for T2w CMR, 59% (95% CI: 56% to 73%) for EGE, and 67% (95% CI: 59% to 75%) for LGE. The diagnostic accuracies of mapping techniques were 63% (95% CI: 53% to 73%) for myocardial T2, 69% (95% CI: 60% to 76%) for native myocardial T1, and 76% (95% CI: 68% to 82%) for global myocardial ECV. The diagnostic accuracy of CMR was significantly improved to 90% (95% CI: 84% to 95%) by a stepwise approach, using the presence of LGE and myocardial ECV ≥27% as diagnostic criteria, compared with 79% (95% CI: 71% to 85%; p = 0.0043) for the Lake-Louise criteria. ConclusionsIn patients with clinical evidence for subacute, severe myocarditis, ECV quantification with LGE imaging significantly improved the diagnostic accuracy of CMR compared with standard Lake-Louise criteria.

Validation of global longitudinal strain and strain rate as reliable markers of right ventricular dysfunction: comparison with cardiac magnetic resonance and outcome.

BackgroundRight ventricular (RV) dysfunction in ischemic cardiomyopathy (ICM) is associated with poor prognosis, but RV assessment by conventional echocardiography remains difficult. We sought to validate RV global longitudinal strain (RVGLS) and global longitudinal strain rate (RVGLSR) against cardiac magnetic resonance (CMR) and outcome in ICM.MethodsIn 57 patients (43 men, 64 ± 12 years) with ICM who underwent conventional and strain echocardiography and CMR, RVGLS and RVGLSR were measured off-line. RV dysfunction was determined by CMR [RV ejection fraction (RVEF) < 50%]. Patients were followed over 15 ± 9 months for a composite of death and hospitalization for worsening heart failure.ResultsRVGLS showed significant correlations with CMR RVEF (r = -0.797, p < 0.01), RV fractional area change (RVFAC, r = -0.530, p < 0.01), and tricuspid annular plane systolic excursion (TAPSE, r = -0.547, p < 0.01). RVGLSR showed significant correlations between CMR RVEF (r = -0.668, p < 0.01), RVFAC (r = -0.394, p < 0.01), and TAPSE (r = -0.435, p < 0.01). RVGLS and RVGLSR showed significant correlations with pulmonary vascular resistance (r = 0.527 and r = 0.500, p < 0.01, respectively). The best cutoff value of RVGLS for detection of RV dysfunction was -15.4% [areas under the curve (AUC) = 0.955, p < 0.01] with a sensitivity of 81% and specificity 95%. The best cutoff value for RVGLSR was -0.94 s-1 (AUC = 0.871, p < 0.01), sensitivity 72%, specificity 86%. During follow-up, there were 12 adverse events. In Cox-proportional hazard regression analysis, impaired RVGLS [hazard ratio (HR) = 5.46, p = 0.030] and impaired RVGLSR (HR = 3.95, p = 0.044) were associated with adverse clinical outcome.ConclusionCompared with conventional echocardiographic parameters, RVGLS and RVGLSR correlate better with CMR RVEF and outcome.

Improved Detection of Cardiac Sarcoidosis Using Magnetic Resonance with Myocardial T2 Mapping

Improved Detection of Cardiac Sarcoidosis Using Magnetic Resonance with Myocardial T2 Mapping

Electrocardiographic Q-Wave “Remodeling” in Reperfused ST-Segment Elevation Myocardial Infarction: Validation Study With CMR

The aim of this study was to evaluate the evolution in Q-wave expression during the first 5 years after a primary, successfully reperfused ST-segment elevation myocardial infarction (MI), using cardiac magnetic resonance (CMR) for infarct location, and to depict changes in infarct size and left ventricular remodeling over time. In the absence of QRS confounders, abnormal Q waves are usually diagnostic of myocardial necrosis. It is hypothesized that Q-wave regression after MI could be related to smaller infarct sizes. Late gadolinium enhancement accurately depicts MI of any age. Forty-six MI patients underwent electrocardiography and CMR at 1 week (baseline), 4 months, 1 year, and 5 years post-infarction. Conventional CMR parameters were analyzed, and infarct presence, location, and size were assessed using late gadolinium enhancement CMR. Infarct locations were anterior or nonanterior (inferior and/or lateral), using late gadolinium enhancement CMR as a reference. For each time point, patients were classified as having a diagnostic/nondiagnostic electrocardiogram (ECG) using the European Society of Cardiology/American College of Cardiology Foundation/American Heart Association/World Heart Federation consensus criteria for previous Q-wave infarct. At baseline, 11 patients (23%) did not meet the criteria for Q-wave MI. Non–Q-wave infarcts were significantly smaller than Q-wave infarcts (p < 0.0001). All anterior Q-wave infarcts (n = 17) were correctly localized, whereas in 7 of 19 nonanterior Q-wave infarcts, the location or extent of the infarct was misjudged by electrocardiography. At 4-month/1-year follow-up, in 10 patients (3 anterior/7 nonanterior), the ECG became nondiagnostic. The ECG remained nondiagnostic at 5-year follow-up. A cutoff infarct size of 6.2% at 1 year yielded a sensitivity of 89% and a specificity of 74% to predict the presence or absence of Q waves. The incidence of nondiagnostic ECGs for previous MI using the current European Society of Cardiology/American College of Cardiology Foundation/American Heart Association/World Heart Federation criteria is substantial and increases with time post-infarction from 23% immediately post-infarction to 44% at 5-year follow-up.

Circulation: Clinical Summaries

<i>Circulation:</i> Clinical Summaries