Steady-state Free Precession Cine Research Articles

SAT-540 Primary Aldosteronism Represents Earlier Myocardial Fibrosis Than Essential Hypertension by T1 Mapping

Introduction:Primary aldosteronism (PA) is associated with cardiovascular disease and has increased cardiovascular morbidity. Several studies had demonstrated that PA shows more serious myocardial fibrosis compared with essential hypertension (EH) using late Gadolinium-enhanced (LGE) imaging [1, 2]. However, the early myocardial change may not be detected by LGE. Recently, cardiac MRI T1 mapping emerged to be a sensitive technique in detecting early changes of myocardium quantitatively. Our study aimed to demonstrate the early myocardial change in PA patients by applying the T1-mapping technique.Method:81 (male: 25; age: 48±12 years) PA[3] and 44 (male: 21; age: 47±14 years) EH patients diagnosed by the Department of Endocrinology and metabolism according to the 2016 TES guidelines for PA were recruited from September 2018 to May 2019. All the subjects underwent cardiac MRI examinations on a 3T MRI scanner (MAGNETOM Trio a Tim System, Siemens Healthcare, Erlangen, Germany), including steady-state free-precession (SSFP) cine imaging and modified Look-Locker inversion recovery (MOLLI) imaging for T1 mapping. Functional parameters were obtained from cine images by the Argus software (Siemens Healthcare, Erlangen, Germany).The mid-ventricular native T1 value was acquired using the QMass software (Medis, Leiden, The Netherlands). Native T1 value and cardiac function parameters were analyzed between the two groups. Differences of continuous variables were analyzed by Student’s t-test or Mann-Whitney U-test, and the relationships between native T1 value and physiological variables were analyzed by multiple linear regression method.Results:The age (PA: 48±12 years vs EH: 47±14 years; p=0.720) and BMI (PA: 25.06±3.73 vs EH: 25.17±2.83; P=0.874) between two groups had no significant differences. The PA group had a significant higher aldosterone/renin ratio (ARR) than those in the EH group (114.6 (48.7-474.8)ng/dl:ng/ml.h vs 7.6 (4.2-13.8) ng/dl:ng/ml.h; p<0.001). All functional parameters including LVEDVI (PA: 78.66 (72.4-90.6) ml/m2 vs EH: 75.8 (64.3-85.8) ml/m2; p=0.054); LVESVI (PA: 31.7 (26.2-38.4) ml/m2 vs EH: 29.3 (24.9-36.2) ml/m2; p=0.152); LVEF (PA: 59.9 (53.3-65.0)% VS EH: 59.2(55.3-65.6)%; p=0.679); LVmassi (PA: 58.5(47.7-67.7) g/m2 vs EH: 54.9 (47.6-60.1) g/m2; p=0.463) had no differences between the two groups. However, native T1 values were higher in PA group than those in EH group (1227±40ms vs 1203±45ms). The multiple linear regression analysis showed that gender (Beta=-27.678, p<0.001) and PA (Beta=-17.287, p=0.031) were independently related to the native T1 values.Conclusion:PA patients represent more severe and earlier myocardium damage and this might be related to cardiovascular morbidity. The T1-mapping technique in cardiac MRI is more sensitive to evaluate the left ventricular function and to detect the myocardial fibrosis in PA patients.

Diagnostic and prognostic value of right ventricular eccentricity index in pulmonary artery hypertension.

The right ventricle experiences dynamic changes under pressure overload in pulmonary artery hypertension. This study aimed to evaluate the diagnostic and prognostic value of right ventricular eccentricity index (RVEI) in pulmonary artery hypertension. A total of 100 pulmonary artery hypertension patients (mean age, 36.85 (SD, 13.60) years; males, 30.0%) confirmed by right heart catheterization and 147 healthy volunteers (mean age 45.58 (SD, 17.58) years; males, 42.50%) were enrolled in this prospective study. All participants underwent cardiac magnetic resonance imaging (MRI) examination, and balanced steady-state free precession (bSSFP) cine sequences were acquired. RVEI was measured on short-axis cine images at the mid-ventricular level of the right ventricle in end systole. The study found that RVEI was significantly lower in pulmonary artery hypertension patients than in healthy volunteers (1.84 (SD, 0.40) vs. 2.46 (SD, 0.40); p < 0.001). In pulmonary artery hypertension patients, RVEI was correlated with log(NT-proBNP) (r = -0.388; p < 0.001), right ventricular end-diastolic volume index (r = -0.452; p < 0.001), right ventricular end-systolic volume index (r = -0.518; p < 0.001), and right ventricular ejection fraction (r = 0.552; p < 0.001). RVEI could discriminate pulmonary artery hypertension patients from healthy volunteers with 91.8% sensitivity and 68.0% specificity. Over median follow-up of 14.8 months (interquartile range: 6.7-26.9 months), RVEI was demonstrated to be an independent predictor for adverse outcome (HR = 0.076; 95% CI, 0.013-0.458; p = 0.005). In conclusion, MRI-derived RVEI appears to be a useful diagnostic and prognostic value in pulmonary artery hypertension, and it provides incremental value to risk stratification strategy.

Right and left ventricular interactions, strain, and remodeling in repaired pulmonary stenosis patients with preserved right ventricular ejection fraction: A cardiac magnetic resonance study.

Right ventricular dilation and dysfunction is a common long-term complication in patients with repaired pulmonary stenosis (rPS). Additionally, abnormal right and left ventricular interactions have been reported in right-sided heart defect after intervention, including in pulmonary stenosis. To analyze ventricular strain, remodeling, and left and right ventricular interactions in rPS patients with preserved right ventricular ejection fraction (RVEF) compared with healthy children using cardiac magnetic resonance. A cross-sectional study. In all, 34 rPS patients and 10 healthy children volunteers (controls). 3.0T/2D balanced steady-state free precession (2D b-SSFP) cine, late gadolinium enhancement (LGE), and 2D phase contrast (2D-PC). Pulmonary regurgitation (PR) fractions of the main pulmonary artery, biventricular volumes, masses, function, and cardiac strain. Mann-Whitney U-test, t-test, Pearson correlation coefficients, Spearman's correlation coefficients, and intraclass correlation coefficients analysis were performed. For group analysis, the right ventricular (RV) global circumferential strain and radial strain were significantly increased in patients when compared with controls (-13.57 ± 2.69 vs. -5.91 ± 3.16, P < 0.001; 25.31 ± 8.12 vs. 9.87 ± 5.32, P < 0.001, respectively). The fraction of PR displayed moderate correlation with right ventricular end-diastolic volume index (RVEDVi) (r = 0.452, P = 0.022). RVEDVi and mass index were larger in patients vs. control (104.92 ± 27.46 vs. 85.15 ± 11.98, P = 0.016; 18.28 ± 4.95g/m2 vs. 11.67 ± 2.14 g/m2 , P < 0.001, respectively). Patients presented with preserved left ventricular ejection function, but was lower than healthy controls (60.89% ± 4.89% vs. 65.95% ± 4.56%, P = 0.006). Regional circumferential strain of segment 3 of left ventricle (LV) were significantly decreased in patients (-7.79 ± 6.52 vs. -13.56 ± 3.22, P = 0.003). Compensated increased RV strain, myocardial remodeling of RV, and adverse right and left ventricular interactions occur in rPS patients with preserved RVEF. The decreased interventricular septum strain may lead to impaired LV function due to RV dilation as a result of PR. 3 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2020;52:129-138.

Quantitative mechanical dyssynchrony in dilated cardiomyopathy measured by deformable registration algorithm.

To investigate the diagnostic value and reproducibility of deformable registration algorithm (DRA)-derived mechanical dyssynchrony parameters in dilated cardiomyopathy (DCM) patients. The present study included 80 DCM patients (40 with normal QRS duration (NQRS-DCM); 40 with left bundle branch block (LBBB-DCM)) and 20 healthy volunteers. The balanced steady-state free-precession (bSSFP) cine images were acquired using a 3.0T scanner. Mechanical dyssynchrony parameters were calculated based on DRA-derived segmental strain, including uniformity ratio estimate (URE) and standard derivation of time-to-peak (T2Psd) parameters in circumferential, radial, and longitudinal orientations. DCM patients showed significant mechanical dyssynchrony reflected by both URE and T2Psd parameters compared with controls. Among DCM patients, LBBB-DCM showed decreased CURE (0.78 ± 0.21 vs. 0.93 ± 0.05, p< 0.001) and RURE (0.69 ± 0.14 vs. 0.83 ± 0.15, p= 0.001), and increased T2Psd-Ecc (median with interquartile range, 94.1 (54.4-123.2) ms vs. 63.7 (44.9-80.4) ms, p= 0.003) and T2Psd-Err (91.1 (61.1-103.2) ms vs. 62.3 (46.3-104.5) ms, p= 0.041) compared with NQRS-DCM patients. CURE showed a strong correlation with QRS duration (r= - 0.54, p< 0.001), with maximum AUC (0.791) to differentiate LBBB-DCM from NQRS-DCM patients. Improved intra- and inter-observer reproducibility was found using URE indices (coefficient of variation (CoV), 1.20-3.17%) than T2Psd parameters (CoV, 15.28-41.18%). The DRA-based CURE showed significant correlation with QRS duration and the highest discriminatory value between LBBB-DCM and NQRS-DCM patients. URE indices showed greater reproducibility compared with T2Psd parameters for assessing myocardial dyssynchrony in DCM patients. • The strain analyses based on DRA suggested that DCM patients have varying degrees of mechanical dyssynchrony and there is a significant difference from normal controls. • CURE showed the strongest correlation with QRS duration and was the best parameter for differentiating DCM patients with normal QRS duration from patients with LBBB, and with normal controls. • URE indices showed improved reproducibility compared with T2Psd parameters in all three orientations (circumferential, radial, and longitudinal).

Children With Acute Myocarditis Often Have Persistent Subclinical Changes as Revealed by Cardiac Magnetic Resonance.

Many children presenting with myocarditis may not fully recover and have long-term complications, including dilated cardiomyopathy. Magnetic resonance imaging (MRI) has a potential for early detection of persistent changes with long-term implications, but is not performed routinely in the monitoring of myocarditis. To monitor adolescents who present with acute myocarditis using MRI and routine diagnostic tests over the short- to mid-term. Prospective. Eighteen consecutive adolescents (median age 15.5, interquartile range 14.8-16.9 years, 78% male) with acute myocarditis. A 3T scanner including cine steady-state free precession (SSFP), dark-blood T2 -weighted (T2 W) images, and late gadolinium enhancement (LGE). The diagnosis of acute myocarditis was based on clinical symptoms and signs and MRI criteria (cine, T2 -W images, LGE). Follow-up MRI was performed after median 7 months (range 6-9 months). Other routine diagnostic tests included electrocardiogram (ECG), high-sensitivity troponin levels, transthoracic echocardiography, and Holter monitoring. Fisher's exact test, Wilcoxon test for paired samples, Mann-Whitney test for independent samples, Kruskal-Wallis test. At baseline, 17 patients (94%) had elevated troponin levels and/or ST-T changes on resting ECG; ECG showed depressed left ventricular ejection fraction (LVEF<50%) in four patients (22%). At follow-up there was a complete recovery in 16 patients (89%) observed with routinely performed tests, with two cases of persistent ventricular arrhythmia. Despite normal left ventricular volume and LVEF, MRI disclosed ongoing active inflammation in five patients (28%), healed myocarditis with persistent scars in eight patients (44%), and complete resolution of initially observed changes in five patients (28%). In children with acute myocarditis, despite normalization of other routinely assessed parameters (including LVEF), there is a high prevalence of persistent MRI changes showing ongoing disease or remnant scars at follow-up. MRI may allow early detection and prevention of long-term complications of myocarditis in the follow-up care of children with acute myocarditis. 2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2020. J. Magn. Reson. Imaging 2020;52:488-496.

Clinical experience regarding safety and diagnostic value of cardiovascular magnetic resonance in patients with a subcutaneous implanted cardioverter/defibrillator (S-ICD) at 1.5\u2009T

BackgroundCardiovascular magnetic resonance (CMR) studies in patients with implanted cardioverter/defibrillators (ICD) are increasingly required in daily clinical practice. However, the clinical experience regarding the feasibility as well as clinical value of CMR studies in patients with subcutaneous ICD (S-ICD) is still limited. Besides safety issues, image quality and analysis can be impaired primarily due the presence of image artefacts associated with the generator.MethodsTwenty-three patients with an implanted S-ICD (EMBLEM, Boston Scientific, Marlborough, Massachusetts, USA; MR-conditional) with suspected cardiomyopathy and/or myocarditis underwent multi-parametric CMR imaging. Studies were performed on a 1.5 T CMR scanner after device interrogation and comprised standard a) balanced steady state free precession cine, b) T2 weighted-edema, c) velocity-encoded cine flow, d) myocardial perfusion, e) late-gadolinium-enhancement (LGE)-imaging and f) 3D-CMR angiography of the aorta. In case of substantial artefacts, alternative CMR techniques such as spoiled gradient-echo cine-sequences and wide-band inversion-recovery LGE (wb-LGE) sequences were applied.ResultsSuccessful CMR studies could be performed in all patients without any case of unexpected early termination or relevant technical complication other than permanent loss of the S-ICD system beeper volume in 52% of our patients. Assessment of cine-CMR images was predominantly impaired in the left ventricular (LV) anterior, lateral and inferior wall segments and a switch to spoiled gradient echo-based cine-CMR allowed an accurate assessment of cine-images in N = 17 (74%) patients with only limited artefacts. Hyperintensity artefacts in conventional LGE-images were predominantly observed in the LV anterior, lateral and inferior wall segments and image optimisation by use of the wb-LGE was helpful in 15 (65%) cases. Aortic flow measurements and 3D-CMR angiography were assessable in all patients Perfusion imaging artefacts precluded a meaningful assessment in at least one half of the patients. A benefit in clinical-decision making was documented in 17 (74%) patients in the present study.ConclusionSafe 1.5 T CMR imaging was possible in all patients with an S-ICD, though the majority had permanent loss of the S-ICD beeper volume. Achieving good image quality may be challenging in some patients - particularly for perfusion imaging. Using spoiled gradient echo-based cine-sequences and wb-LGE sequences may help to reduce the extent of artefacts, thereby allowing accurate cardiac assessment. Thus, 1.5 T CMR studies should not be withhold in patients with S-ICD for safety concerns and/or fear of extensive imaging artefacts precluding successful image analysis.

1045 T1-mapping and CMR feature tracking in mitral valve prolapse

Abstract BACKGROUND Several studies suggest that mitral valve prolapse (MVP) can be related to sudden cardiac death, owing to sustained ventricular arrhythmias (VAs). In patients with sudden cardiac death and complex VAs, a high percentage of either left ventricle (LV) papillary muscle fibrosis or inferobasal fibrosis has been described using cardiac magnetic resonance (CMR) with late gadolinium enhancement technique (LGE). However, LGE presents several technical limitations and requires contrast agent administration. Thanks to T1 mapping (T1-map) and feature tracking (FT) techniques, CMR may identify myocardial fibrosis and deformation abnormalities respectively. We sought to demonstrate that, in patients with MVP, T1 map can accurately identify the presence of myocardial fibrosis which, being related to myocardial stiffness, is associated to abnormal deformation indexes at CMR FT strain evaluation. METHODS Consecutive patientswith indication to mitral valve surgery for severe mitral regurgitation due to mitral valve prolapse were prospectively enrolled. CMR including Modified Look-Locker (MOLLI) sequences for T1 mapping was performed in each patient. In addition, CMR FT analysis of steady state free precession (SSFP) cine images was performed to obtain 2D global and segmental circumferential and radial strains. RESULTS 70 consecutive patients (age: 59 ± 12) were successfully evaluated with CMR. T1 native values were significantly higher in the basal and mid LV inferolateral wall compared to the remote myocardium (1074 ± 67 vs 1046 ± 40 msec, p&amp;lt; 0.001). Moreover, the average radial and circumferential strains of the basal and mid LV inferolateral were significantly reduced compared to those of the remote myocardium (21.1 ± 10.4 and -12.8 ± 5.6 vs 31.6 ± 9.1 and -17.3 ± 3.6 respectively, p &amp;lt; 0.001). CONCLUSIONS In patients with MVP and severe mitral regurgitation native T1 values of the LV inferolateral are higher as compared to remote myocardium and associated with reduced circumferential and radial strains. T1 mapping and CMR FT strain may be used as tools for the early identification of tissue changes in the LV inferolateral myocardial segment. Further studies are needed to evaluate if these changes are able to predict LGE development and are associated with higher risk for VAs

P729 A shocking tumor

Abstract Introduction Primary cardiac tumors are a relatively uncommon condition, which may appear both in asymptomatic patients or in a myriad of clinical presentations. Imaging techniques are crucial for its diagnosis, and a multi-modality approach may be useful in the evaluation of this masses. Case description A 57 year-old man with history of hypertension presented in the emergency department with acute pulmonary edema and cardiogenic shock. He was admitted to the coronary care unit, and on bedside echocardiography a mass on the tricuspid valve was observed. Upon clinical improvement, a cardiac CT and cardiac MRI was performed (figure 1). A solid mass with no calcium content and dependent exclusively on the anterior leaflet of the tricuspid valve was seen on CT-scan (fig 1, A and B). Thrombus on the right atrial appendage could also be appreciated. MRI confirmed the presence of a 18x19 mm mass with isointense signal on T1-turbo spin echo black-blood (fig 1, C) and cine steady-state free precession sequences, whereas an hyperintense signal was evident on T2 weighted images (T2-STIR; fig 1 D). In first pass sequences the central core was hypointense and late gadolinium enhancement showed peripheral enhancement with a non captating central core (fig 1, E). The patient underwent surgery and the anatomopathological results showed a tumor constituted by dense connective tissue, scarce cellular content and an avascular matrix of mucopolysaccharides, elastic fibers and fusiform cells consistent with the diagnosis of papillary fibroelastoma. Discussion The imaging characteristics of papillary fibroelastoma are not commonly reported on MRI. We present an unusually large right-sided fibroelastoma with a characteristic distribution of late gadolinium enhancement, which has not been consistently described on a fibroelastoma. Cardiac tumors are rare, and a non-invasive differential diagnosis is always a challenge. A multi-modality approach (echocardiography, cardiac-CT and cardiac MRI) as well as integration of relevant morphological information, including the location of the lesion and tissue characteristics was essential to the orientate the most plausible diagnosis. The distinctive images are presented. Abstract P729 Figure 1.

Deep Learning-based Prescription of Cardiac MRI Planes.

To develop and evaluate a system to prescribe imaging planes for cardiac MRI based on deep learning (DL)-based localization of key anatomic landmarks. Annotated landmarks on 892 long-axis (LAX) and 493 short-axis (SAX) cine steady-state free precession series from cardiac MR images were retrospectively collected between February 2012 and June 2017. U-Net-based heatmap regression was used for localization of cardiac landmarks, which were used to compute cardiac MRI planes. Performance was evaluated by comparing localization distances and plane angle differences between DL predictions and ground truth. The plane angulations from DL were compared with those prescribed by the technologist at the original time of acquisition. Data were split into 80% for training and 20% for testing, and results confirmed with fivefold cross-validation. On LAX images, DL localized the apex within mean 12.56 mm ± 19.11 (standard deviation) and the mitral valve (MV) within 7.68 mm ± 6.91. On SAX images, DL localized the aortic valve within 5.78 mm ± 5.68, MV within 5.90 mm ± 5.24, pulmonary valve within 6.55 mm ± 6.39, and tricuspid valve within 6.39 mm ± 5.89. On the basis of these localizations, average angle bias and mean error of DL-predicted imaging planes relative to ground truth annotations were as follows: SAX, -1.27° ± 6.81 and 4.93° ± 4.86; four chambers, 0.38° ± 6.45 and 5.16° ± 3.80; three chambers, 0.13° ± 12.70 and 9.02° ± 8.83; and two chamber, 0.25° ± 9.08 and 6.53° ± 6.28, respectively. DL-based anatomic localization is a feasible strategy for planning cardiac MRI planes. This approach can produce imaging planes comparable to those defined by ground truth landmarks.© RSNA, 2019 Supplemental material is available for this article.

Accuracy and Time-Efficiency of an Automated Software Tool to Assess Left Ventricular Parameters in Cardiac Magnetic Resonance Imaging.

Routine manual tracing of cardiac contours is time-consuming and subject to variability. A fully automated software tool may improve reading efficiency. This study was performed to assess the accuracy, reliability, and time-efficiency of a fully automated left ventricular (LV) segmentation software tool to calculate LV volumes and function compared with conventional manual contouring. Sixty-seven consecutive patients (53 male, mean age 62.5±10.9 y) underwent adenosine stress/rest perfusion cardiac magnetic resonance examination to rule out myocardial ischemia. Double-oblique short-axis 6-mm slice thickness steady-state free precession cine images were acquired to assess LV ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), and stroke volume (SV) using manual contour tracing and a recently developed fully automated software tool. The length of time needed to obtain LV volumes with each segmentation method was also compared. Compared with manual contouring, the fully automated software tool minimally underestimated LV-EF (mean difference of 2.9%±3.9%) and SV (mean difference of 4.4±8.5 mL) and slightly overestimated ESV (mean difference of -6.4±10.8 mL) and LV mass (mean difference of -14±20.4 g). EDV quantification did not statistically differ. Reliability for EF (concordance correlation coefficient [CCC]=0.92, 95% confidence interval [CI], 0.88-0.95), EDV (CCC=0.98, 95% CI, 0.97-0.99), ESV (CCC=0.96, 95% CI, 0.94-0.97), SV (CCC=0.93, 95% CI, 0.89-0.95), and LV mass (CCC=0.84, 95% CI, 0.76-0.89) was very good. The evaluated software allowed to quantify LV parameters with a 79% reduction in the time required for manual contouring (414.7±91 s vs. 85±16.1 s, respectively, P<0.001). Quantification of LV volumes using the evaluated fully automated segmentation software is accurate and time-efficient.

P5260Differences in myocardial mechanics between dilated cardiomyopathy and ischemic cardiomyopathy by CMR derived feature tracking strain - A propensity score-matched study

Abstract Background Adult heart failure in industrialized nations is primarily due to dilated (DCM) and ischemic cardiomyopathy (ICM). Both diseases are characterized by different pathological pathways. While ICM is predominantly caused by local, subendocardial myocyte necrosis, DCM is characterized by a general myocyte apoptosis involving all myocardial layers. Using feature tracking, longitudinal, circumferential, and radial motion of the left ventricle (LV) can be measured, which allows the function of subendocardial, mostly longitudinal orientated, and subepicardial, mostly circumferential orientated fibers to be assessed independently. Purpose It was the aim of our study to detect differences of LV motion between DCM and ICM patients in a propensity score-matched cohort. Methods Between April 2017 and December 2018 we included 845 patients with a clinical indication for CMR in our tertiary care center registry. Out of this cohort we identified 273 patients with ICM and 126 with DCM. Propensity score matching was used to pair patients in each group based on their indexed enddiastolic volume (EDVi), ejection fraction (EF), septal T1. Feature tracking technique was used for strain analyses quantified on steady state free precession cine CMR images yielding six strain parameters. Results Propensity score matching yielded 59 patients in each group (ICM mean age 59.4±13.0 years, 11 females; DCM mean age 66.5±10.6 years, 15 females; LV-EF 32.6±11.4% vs. 33.0±14.2%, p=0.8178; EDVi 124.2±36 ml/m2 vs. 132.9±42 ml/m2, p=0.0909; native T1 values 1161±66 ms vs. 1164±59 ms, p=0.7049). There was no difference in global longitudinal strain between ICM and DCM patients (−10.9±4.4% vs. −10.6±5.8%, p=0.686), whereas global circumferential strain and radial strain were reduced in DCM patients (−12.0±4.3% vs. −10.31±4.8%, p=0.0190 and 21.1±8.9% vs. 18.0±15.5%, p=0.0386). Conclusion Our data confirm the inherently different mechanics of ICM and DCM patients. While myocardial fibres are globally affected in DCM, myocardial damage is predominantly confined to subendocardial layers in ICM despite equally reduced EF.

P2728Prognostic impact of left atrial function in patients with cardiac amyloidosis: a cardiac magnetic resonance study

Abstract Background Left atrial function (AEF) is a parameter of paramount importance that has a prognostic value in a number of heart conditions. Cardiac involvement in both light-chain and transthyretin amyloidosis is the main driver of prognosis and influences treatment strategies. Cardiac magnetic resonance (CMR) provides high quality images of the left and right atria using high temporal resolution steady state free precession (SSFP) cine sequences. Purpose The aim of our study was to assess by CMR left atrial function and his correlation with prognosis in patients with cardiac amyloidosis. Method We enrolled 80 consecutive patients with diagnosis of cardiac amyloidosis: 38 patients (47%) with light-chain and 42 patients (53%) with transthyretin one. CMR was performed using a 1.5-T scanner. In all subjects, the study of atria was obtained by acquiring cine steady-state free precession (SSFP). Left Atrial function was evaluated by the ratio between the maximum and the minimum LA volume. A median follow up of 937 days was performed and 36 patients (44%) died of cardiac causes. We evaluated cardiac death as endpoint. We split out all the patient in 4 different quartiles depending on left atrial function: in the first quartile patients with AEF≤14% that reflects severe atrial dysfunction, in the second quartile patients with AEF between 14 and 19%, in the third quartile patients with AEF between 19 and 36% and in the last one patients with AEF≥36% that represent patients with normal value of left atrial function. Results We found that CMR assessed left atrial function allowed to individuate and stratify the prognosis in patients with cardiac amyloidosis. The most effective parameter to evaluate cardiac death was left atrial function with a cut off ≤14% that could predict cardiac related mortality with the same accuracy in both light-chain and transthyretin amyloidosis patients. Kaplan Meier analysis showed that patients with AEF≤14% had a worse prognosis as compared to patient with AEF≥14% (log rank p. 0001). Furthermore patients with AEF≤14% have a cardiac death risk of 32% at 1 year and 61% at 3 years. Kaplan Meier analysis Conclusion Cardiac magnetic resonance is an imaging modality that allows to individuate with great accuracy left atrial function in patients with various heart conditions and especially cardiac amyloidosis. CMR left atrial function assessment clearly identifies a subgroup of cardiac amyloid patients with an increased risk of death.

P5287Influence of contrast and spatial resolution on myocardial strain results using feature tracking MRI

Abstract Background Feature tracking is a new post-processing algorithm for calculating myocardial strain from cardiac magnetic resonance (CMR) cine images. Quantification of myocardial deformation promises to detect myocardial abnormalities early in the course of disease. However, no uniform standards for image acquisition and processing are available. Purpose Analysing the influence of spatial resolution and contrast agent on quantitative myocardial strain results. Methods Seventy-five patients in sinus rhythm were prospectively enrolled and underwent a standardised CMR exam using a 1.5 Tesla scanner. For feature tracking analysis, steady-state free-precession (SSFP) cine images in long and short axes were acquired in 3 variants: 1. Native standard cine (spatial resolution 1.4x1.4x8mm3). 2. Native cine with lower spatial resolution (2.0x2.0x8mm3). 3. Standard cine equal to variant 1 but acquired 5 minutes after i.v.-administration of 0.2mmol/kg body weight gadoteracid. Group A consisted of 50 patients with normal left ventricular ejection fraction, no regional wall motion abnormality and no evidence of fibrosis based on Late Gadolinium Enhancement. Group B comprised 25 patients with evidence of infarct-like myocardial scar in the analyzed planes. Using dedicated feature tracking software, circumferential, longitudinal and radial strain were calculated as mean of the six midventricular myocardial segments for group A. For group B, the analysis focused on the infarcted segments. Results Figure 1 summarises the strain results, given as mean standard deviation. (The p-values stem from paired t-tests (group A) and Wilcoxon tests (group B), respectively. Significance is highlighted by *). In group A, circumferential and radial strain decreased significantly after Gadolinium administration, while longitudinal strain increased significantly with lower spatial resolution. In group B, circumferential, longitudinal and radial strain results of the infarcted segments increased significantly with lower spatial resolution, while Gadolinium had no statistically significant influence on strain results. Figure 1 Conclusion Quantitative myocardial strain results obtained by CMR feature tracking are significantly influenced by spatial resolution and Gadolinium administration. Standardised image acquisition seems fundamental for reliable and comparable CMR strain analysis.

4934Biventricular global and regional strain measured by cardiovascular magnetic resonance based tissue tracking

Abstract Background CMR based tissue tracking (CMR-TT), considered as a novel modality, provides additional insight into left and right ventricular (LV/RV) mechanical function and deformation. The vendor-specific reference values of global and regional strains for volunteers without history of cardiovascular disease are necessary as an important step in clinical routine to help detect early abnormality. Purpose To determine the reference value of LV/RV multi-dimensional global and segmental strains and diagnostic specificity of global longitudinal peak strain (GLS). Biventricular global and segmental radial, circumferential and longitudinal systolic peak strains (GRS, GCS, GLS and SRS, SCS, SLS) of 150 healthy adults in three age subgroups (G20–40, G41–60 and G61–80) were derived by post-hoc imaging software in standard steady-state free precession cine images acquired at 1.5T. LV strains were calculated with three-dimensional (3D) CMR-TT in the modified AHA 16-segment model via a short-axis stack and long axis 2-, 3-, 4-chamber cine images, and RV strains were generated with 2D CMR-TT via 4-chamber cine images. Results The reference values of LV global peak strains resulted as 44.4±13.0% for GRS, −17.0±2.7% for GCS, and −15.4±2.3% for GLS, respectively. RV-GLS was measured as −24.9±5.1%. Global and segmental strains might differ between males and females. Females showed significant age-associated difference of LV global peak strains (P&lt;0.05) as the opposite of males (Figure 1). Females also presented higher magnitude of LV global peak strains than males in the eldest group G61–80 (P&lt;0.05). Unlike LV, no age-associated difference of RV-GLS was detected in both gender groups. However, females showed less negative RV-GLS than males in G20–40 and more negative RV-GLS than males older than 40 years old (P&lt;0.05). The local discrepancy of biventricular SRS, SCS and SLS was observed. It seemed that LV mid-cavity played a more essential role on LV shortening (more negative SCS and SLS) than wall thickening (smaller SRS) compared with base and apex. RV basal and mid SLS, derived from segment 1–4, was more negative than apical SLS derived from segment 5–6. The specificity of LV- and RV-GLS cut-off value (mean value+1.96*standard deviation) generated from the vendor-, age- and gender-specific reference value in evaluating heart contractile function reached 97.3% and 94.7%, respectively. Conclusions Considering the vendor-, gender- and age-associated difference of biventricular global strains, specific reference values need to be established to facilitate the wide application of strain in clinical routine. Meanwhile, segmental strains are also fundamental for detecting local abnormality of myocardial deformation.

Myocardial velocity, intra-, and interventricular dyssynchrony evaluated by tissue phase mapping in pediatric heart transplant recipients.

Endomyocardial biopsy (EMB) is the standard method for detecting allograft rejection in pediatric heart transplants (Htx). As EMB is invasive and carries a risk of complications, there is a need for a noninvasive alternative for allograft monitoring. To quantify left and right ventricular (LV & RV) peak velocities, velocity twist, and intra-/interventricular dyssynchrony using tissue phase mapping (TPM) in pediatric Htx compared with controls, and to explore the relationship between global cardiac function parameters and the number of rejection episodes to these velocities and intra-/interventricular dyssynchrony. Prospective. Twenty Htx patients (age: 16.0 ± 3.1 years, 11 males) and 18 age- and sex-matched controls (age: 15.5 ± 4.3 years, nine males). 5T; 2D balanced cine steady-state free-precession (bSSFP), TPM (2D cine phase contrast with three-directional velocity encoding). LV and RV circumferential, radial, and long-axis velocity-time curves, global and segmental peak velocities were measured using TPM. Short-axis bSSFP images were used to measure global LV and RV function parameters. A normality test (Lilliefors test) was performed on all data. For comparisons, a t-test was used for normally distributed data or a Wilcoxon rank-sum test otherwise. Correlations were determined by a Pearson correlation. Htx patients had significantly reduced LV (P < 0.05-0.001) and RV (P < 0.05-0.001) systolic and diastolic global and segmental long-axis velocities, reduced RV diastolic peak twist (P < 0.01), and presented with higher interventricular dyssynchrony for long-axis and circumferential motions (P < 0.05-0.001). LV diastolic long-axis dyssynchrony (r = 0.48, P = 0.03) and RV diastolic peak twist (r = -0.64, P = 0.004) significantly correlated with the total number of rejection episodes. TPM detected differences in biventricular myocardial velocities in pediatric Htx patients compared with controls and indicated a relationship between Htx myocardial velocities and rejection history. 2 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2020;51:1212-1222.

Clinical evaluation of left ventricular function and morphology using an accelerated k-t sensitivity encoding method in cardiovascular magnetic resonance

ObjectivesTo provide clinical validation of a recent 2D SENSE-based accelerated cardiovascular magnetic resonance (CMR) sequence (accelerated k-t SENSE), investigating whether this technique accurately quantifies left ventricle (LV) volumes, function, and mass as compared to 2D cine steady-state free precession (2D-SSFP).MethodsHealthy volunteers (n = 16) and consecutive heart failure patients (n = 26) were scanned using a 1.5 T MRI system. Two LV short axis (SA) stacks were acquired: (1) accelerated k-t SENSE (5–6 breath-holds; temporal/spatial resolution: 37 ms/1.82 × 1.87 mm; acceleration factor = 4) and (2) standard 2D-SSFP (10–12 breath-holds; temporal/spatial resolution: 49 ms/1.67 × 1.87 mm, parallel imaging). Ascending aorta phase-contrast was performed on all volunteers as a reference to compare LV stroke volumes (LVSV) and validate the sequences. An image quality score for SA images was used, with lower scores indicating better quality (from 0 to 18).ResultsThere was a high agreement between accelerated k-t SENSE and 2D-SSFP for LV measurements: bias (limits of agreement) of 2.4% (− 5.4% to 10.1%), 6.9 mL/m2 (− 4.7 to 18.6 mL/m2), − 1.5 (− 8.3 to 5.2 mL/m2), and − 0.2 g/m2 (− 11.9 to 12.3 g/m2) for LV ejection fraction, end-diastolic volume index, end-systolic volume index, and mass index, respectively. LVSV by accelerated k-t SENSE presented good agreement with aortic flow. Interobserver and intraobserver variabilities for all LV parameters were also high.ConclusionThe accelerated k-t SENSE CMR sequence is clinically feasible and accurately quantifies LV volumes, function, and mass, with short acquisition time and good image quality.

Free-breathing Cardiorespiratory Synchronized Cine MRI for Assessment of Left and Right Ventricular Volume and Function in Sedated Children and Adolescents with Impaired Breath-holding Capacity.

To prospectively compare left ventricular and right ventricular volume, function, and image quality of a free-breathing (FB) cardiorespiratory synchronized balanced steady-state free precession cine MRI sequence with that of a standard of reference breath-hold (BH) technique in sedated children and adolescents who are unable to perform BHs. Cohort 1 included 30 patients able to perform BHs (mean age, 19 years; age range, 9-69 years). Cohort 1 underwent both BH and FB cine short-axis imaging with identical acquisition parameters. Cohort 2 included 63 patients unable to perform BHs (50 sedated patients [mean age, 9 years; age range, 4 months to 28 years], 13 unsedated patients [mean age, 21 years; age range, 8-58 years]). Cohort 2 underwent FB cine imaging in multiple views with spatiotemporal resolution equivalent to BH imaging. Comparative quantitative analysis was performed for left ventricular and right ventricular volumes in cohort 1 and for qualitative image quality scores in all patients. Global left ventricular and right ventricular volumetric indexes and image quality scores were comparable between BH and FB sequences in cohort 1. FB image quality was graded as excellent (37 sequences), good (197 sequences), adequate (26 sequences), and suboptimal (three sequences) for 263 cine sequences in cohort 2. In cohort 1, de facto image acquisition time for FB (6.1 minutes ± 1.9 [standard deviation]) was comparable to the equivalent for BH (6.1 minutes ± 2.6) for a stack of 14 sections. In cohorts of sedated children, adolescents, and young adults unable to perform BHs consistently, left ventricular and right ventricular volumes and function were comparable and image quality was noninferior between FB and standard of reference BH techniques.© RSNA, 2019.

Magnetic resonance imaging of contracting ultrathin cardiac tissue

Objective: Integrating cardiac-tissue patches into the beating heart and evaluating the long-term effects of such integration on cardiac contractility are two challenges in an emerging field of regenerative medicine. This pilot study presents tools for the imaging of contracting multicellular cardiac tissue constructs (MTCs) in vitro and demonstrates the feasibility of tracking the early development of strand geometry and contractions in ultrathin strands and layers of cardiac tissue using CINE MRI. Approach: Cultured, ultrathin (∼50–100-micron) MTCs of rat neonatal cardiomyocytes were plated in rectangular cell chambers (4.5 × 2.0 cm) with and without ultrathin, carbon EP electrodes embedded in the floor of the cell chamber. Two-dimensional, steady-state free precession (SSFP) CINE MRI, cell microscopy, and tissue photography were performed on Days 5–9 of cell development. Potential confounders and MRI artifacts were evaluated using non-contracting cardiac tissues and cell-free chambers filled with the cell-culture medium. Main results: Synchronized contractions formed by Day 7; individual contracting tissue strands became identifiable by Day 9. The global patterns and details of the strand geometry and movement patterns in the SSFP images were in excellent agreement with microscopic and photographic images. No synchronized movement was identifiable by either microscopy or CINE MRI in the non-contracting MTCs or the cell-free medium. The EP recordings revealed well-defined depolarization and repolarization waveforms; the imaging artifacts generated by the carbon electrodes were small. Significance: This pilot study demonstrates the feasibility of imaging cardiac-strand patterns and contractile activity in ultrathin, two-dimensional cardiac tissue in commonly used clinical scanners.

The effect of contrast agents on left ventricular parameters calculated by a threshold-based software module: does it truly matter?

The acquisition of short-axis (SA) cine magnetic resonance (MR) images after the administration of contrast agent (CA) is a common, time-saving technique, but a decreased difference in the blood-myocardium contrast on these steady-state free precession (SSFP) cine scans could change the calculated parameters when using threshold-based papillary and trabecular muscle (PTM) quantification. We studied the effect of CA on the parameters calculated from pre- and post-CA SA cine images in noncompaction cardiomyopathy (NC-CMP) and healthy (H) participants using a threshold-based module. A total of 39 individuals (20 patients and 19 healthy) were included prospectively in this study. After the pre-CA SA images were acquired, i.v. gadobutrol (GA) or gadobenate dimeglumine (GD) (GA vs. GD: NC-CMP = 12 vs. 8; C = 12 vs. 7) was administered, and SA scans were repeated after two minutes. A threshold-based PTM software was used for postprocessing. Pre-CA and post-CA SA images were analyzed, and the parameters were compared in both the NC-CMP and H groups. The left ventricular volumes were significantly larger, while the left ventricular myocardial (LVmass) and trabecular mass (LVtrab) values were significantly smaller on the post-CA scans (NC-CMP: pre-CA vs. post-CA, EDV: 74.0 ± 13.6 vs. 81.1 ± 16.3 ml/m2, ESV: 25.3 ± 7.3 vs. 30.1 ± 11.2 ml/m2, LVmass-ED: 82.5 ± 17.5 vs. 75.7 ± 15.9 g/m2, LVtrab-ED: 25.0 ± 6.6 vs. 18.9 ± 4.7 g/m2; Healthy: preCA vs. post-CA, EDV: 69.7 ± 11.9 vs. 72.2 ± 10.7 ml/m2, ESV: 22.6 ± 5.7 vs. 23.9 ± 6.3 ml/m2, LVmass-ED: 71.3 ± 13.6 vs. 68.7 ± 13.9 g/m2, LVtrab-ED: 19.4 ± 2.6 vs. 16.2 ± 3.0 g/m2; p < 0.05). The decreased blood-myocardium contrast difference on post-CA SSFP SA cine images leads to altered cardiac parameters when using threshold-based software for evaluation.

Free-breathing cine imaging with motion-corrected reconstruction at 3T using SPiral Acquisition with Respiratory correction and Cardiac Self-gating (SPARCS).

To develop a continuous-acquisition cardiac self-gated spiral pulse sequence and a respiratory motion-compensated reconstruction strategy for free-breathing cine imaging. Cine data were acquired continuously on a 3T scanner for 8 seconds per slice without ECG gating or breath-holding, using a golden-angle gradient echo spiral pulse sequence. Cardiac motion information was extracted by applying principal component analysis on the gridded 8 × 8 k-space center data. Respiratory motion was corrected by rigid registration on each heartbeat. Images were reconstructed using a low-rank and sparse (L+S) technique. This strategy was evaluated in 37 healthy subjects and 8 subjects undergoing clinical cardiac MR studies. Image quality was scored (1-5 scale) in a blinded fashion by 2 experienced cardiologists. In 13 subjects with whole-heart coverage, left ventricular ejection fraction (LVEF) from SPiral Acquisition with Respiratory correction and Cardiac Self-gating (SPARCS) was compared to that from a standard ECG-gated breath-hold balanced steady-state free precession (bSSFP) cine sequence. The self-gated signal was successfully extracted in all cases and demonstrated close agreement with the acquired ECG signal (mean bias, -0.22 ms). The mean image score across all subjects was 4.0 for reconstruction using the L+S model. There was good agreement between the LVEF derived from SPARCS and the gold-standard bSSFP technique. SPARCS successfully images cardiac function without the need for ECG gating or breath-holding. With an 8-second data acquisition per slice, whole-heart cine images with clinically acceptable spatial and temporal resolution and image quality can be acquired in <90 seconds of free-breathing acquisition.