Native T1 Mapping Research Articles

Exploring cardiovascular involvement in IgG4-related disease: a case series approach with cardiovascular magnetic resonance

BackgroundIgG4-related disease (IgG4-RD) is a relapsing–remitting, fibroinflammatory, multisystem disorder. Cardiovascular involvement from IgG4-RD has not been systematically characterised. In this study, we sought to evaluate consecutive patients with IgG4-RD using...

Assessment of sub clinical right ventricular ischemia using oxygen sensitive cardiac magnetic resonance imaging in patients with systemic sclerosis: mechanistic insights from advanced cardiac imaging

Abstract Background Cardiac involvement in Systemic Sclerosis (SSc) is common, with manifestations ranging from subclinical to life-threatening 1. Cardiopulmonary complications, including, right ventricular (RV) dysfunction is the leading cause of SSc-related mortality2. Pulmonary arterial hypertension (PAH) occurs in 8-12% of SSc patients and remains a leading cause of death, with a 3-year survival rate around 50%2. The progressive decline in RV function in PAH is often attributed to RV ischemia3. Oxygen Sensitive Cardiac Magnetic Resonance imaging (OS-CMR) has been previously used by our group to assess RV myocardial oxygenation in patients with PAH3, including SSc-associated PAH 3. The objective of this study was to use OS-CMR to assess RV myocardial oxygenation in SSc patients prior to the onset of PAH. Methodology In this prospective, multicentre study, three study groups were established. Group 1 comprised SSc patients without PAH or known cardiac disease. Group 2 included stable PAH patients confirmed by right heart catheterization, matched for age and sex, but without SSc. Group 3 comprised healthy normal volunteers (NV), matched for age and sex. All patients underwent a 3T CMR which included: cine images, rest cine OS-CMR, stress cine OS-CMR, native T1 mapping, stress perfusion, and late gadolinium enhancement (LGE). The primary outcome was change in inferior RV myocardial signal intensity (SI) in diastole, measured by the change in OS-CMR between rest and stress within each group. Two experienced independent reviewers performed the CMR analysis with an inter-assessor correlation coefficient of 0.8, 95% Cl [0.3, 0.9]. Results A total of 44 patients were enrolled. Of these, n=26 group 1 (SSc), n=8 group 2 (PAH), n=10 group 3 (NV). Study results are listed in Table 1. Mean age within the SSc, PAH, and NV groups were 59±10, 67±12 and 57 ±7 years respectively (p=0.482). The RV OS-CMR SI was significantly lower in the SSc group when compared to the NV group (p=0.017). In contrast, there was no significant difference between the PAH and SSc groups (p=0.426), indicating a similar degree of RV ischemia in the established PAH patients and the SSc patients. All SSc patients exhibited inferior and anterior RV insertion fibrosis, with no perfusion defects noted. Five (19%) of SSc patients presented with LGE hyperenhancement in the LV. Eighteen (69%) of SSc patients obtained at least 1 abnormal T1 mapping segment in the LV. Conclusion SSc patients without overt PAH had a similar degree of RV ischemia when compared to patients with overt PAH from other causes. Our findings imply that in SSc, RV adverse effects occur prior to the onset of PAH, and that this effect is mediated by RV ischemia secondary to changes in the microvasculature. Our findings may have screening and/or therapeutic implications.

Efficacy of native T1 mapping for patients with non-ischemic cardiomyopathy and ventricular functional mitral regurgitation undergoing transcatheter edge-to-edge repair

Abstract Background The objectives of this study were to investigate the efficacy of LV myocardial damage assessment by native T1 mapping obtained with cardiac magnetic resonance (CMR) for symptomatic heart failure (HF) patients with non-ischemic cardiomyopathy (NICM) and ventricular functional mitral regurgitation (VFMR) undergoing transcatheter edge-to-edge repair (TEER). Methods We studied 40 symptomatic HF patients with NICM and VFMR undergoing TEER. LV myocardial damage was defined as the native T1 Z-score which was converted from native T1 value obtained with CMR before TEER. The primary endpoint was defined as first re-hospitalization for HF or cardiovascular death over a median follow-up period of 12 months after TEER. Results Multivariable Cox-proportional hazards analysis showed that a native T1 Z-score was the only independent parameter associated with cardiovascular events (hazard ratio: 3.40, 95% confidential interval: 1.51-7.67), and patients with native T1 Z-score < 2.41 experienced significantly fewer cardiovascular events than those with a native T1 Z-score ≥ 2.41 (log-rank P = 0.001). Moreover, such a low native T1 Z-score and more severe VFMR in an effective regurgitant orifice area (EROA) ≥ 0.30 cm2 was associated with fewer cardiovascular events than for a high native T1 Z-score of ≥ 2.41 and less severe VFMR of EROA < 0.30 cm2 (log-rank P = 0.002). Conclusion Assessment of baseline LV myocardial damage by means of native T1 Z-score obtained with CMR without the use of gadolinium-based contrast media is a valuable additional parameter for better management of symptomatic NICM patients with reduced LVEF and VFMR following TEER.

Cardiac magnetic resonance T1 imaging for the diagnosis of cardiac amyloidosis among patients with symptomatic heart failure

Abstract Background Cardiac amyloidosis (CA) is a significant cause of heart failure in elderly patients. However, specific signs in cardiac imaging are lacking, hence bone scintigraphy in combination with screening for monoclonal protein, or myocardial biopsy is required for the diagnosis. Cardiac magnetic resonance (CMR) imaging with T1 mapping is a promising diagnostic tool, which may allow to differentiate causes of left ventricular (LV) hypertrophy, particularly CA. Purpose The aim of this study was to test the diagnostic accuracy of T1 mapping for the diagnosis of CA in elderly patients with symptomatic heart failure and red flags for CA. Methods We prospectively enrolled 120 patients aged above 60 years with symptomatic heart failure NYHA II-IV, LV ejection fraction ≥ 40%, increased LV wall thickness of ≥ 12 mm end-diastolic on echocardiography, and elevated cardiac biomarkers (N-terminal pro-B-type natriuretic peptide (NT-proBNP) ≥ 1,000 ng/L, high-sensitivity cardiac troponin T (hs-cTnT) ≥ 14 ng/L). All patients underwent standardized quantitative CMR with a 3.0T scanner. 99mTc-DPD bone scintigraphy, blood screening for monoclonal protein, and, where applicable, cardiac biopsy, were performed as reference methods in all patients. Primary endpoint was diagnostic accuracy of native T1 mapping for the diagnosis of CA. Results 112 patients were included in the final analysis. Median age was 81.0 years (interquartile range 74.0–85.0 years), and 45% were female. CA was diagnosed in 38 patients (34%), of which 32 suffered from a Transthyretin (ATTR) and 6 patients from light chain (AL) amyloidosis. The areas under the receiver operating characteristic curves for native T1 were 0.713, 0.772, 0.836 for global, septal short-axis (SAX), and septal 4-chamber (4Ch) view measurements. The corresponding value of extracellular volume fraction (ECV) was 0.904 (Figure 1). Based on these results, we developed a new diagnostic algorithm for the diagnosis of CA including T1 septal 4Ch and ECV, with a sensitivity and positive predictive value of both 92.9% and a specificity and negative predictive value of 95.8% (Figure 2). Thereby, contrast application can be avoided in 33% of patients. A definite diagnosis could be provided in 81%. Conclusion CMR with T1 imaging provides a high diagnostic accuracy to diagnose CA in patients with symptomatic heart failure at risk for CA. These data may help to identify underlying causes in heart failure which require specific treatment. An earlier diagnosis of CA may improve outcome of these patients.Figure 1Figure 2

Early Detection of Myocardial Involvement in Thalassemia Intermedia Patients: Multiparametric Mapping by Magnetic Resonance Imaging.

No study has assessed myocardial T1 and T2 values in patients with beta-thalassemia intermedia (β-TI). To assess the prevalence of myocardial involvement in β-TI patients by T2* relaxometry and native T1 and T2 mapping and to determine the correlation of myocardial relaxation times with demographic and clinical parameters. Prospective matched-cohort study. 42 β-TI patients (27 females, 39.65 ± 12.32 years), enrolled in the Extension-Myocardial Iron Overload in Thalassaemia Network, and 42 age- and sex-matched healthy volunteers (27 females, 40.01 ± 11.36 years) and thalassemia major (TM) patients (27 females, 39.27 ± 11.57 years). 1.5 T/multi-echo gradient echo, modified Look-Locker inversion recovery, multi-echo fast-spin-echo, cine balanced steady-state-free precession, and late gadolinium enhancement (LGE) sequences. Hepatic, pancreatic, and left ventricular (LV) T2* values, LV native T1 and T2 values, biventricular ejection fractions and volumes, and presence and extent of replacement myocardial fibrosis. Comparisons between two groups were performed with two-sample t tests, Wilcoxon's signed rank tests, or χ2 testing. Correlation analysis was performed using Pearson's or Spearman's test. P < 0.05 was considered statistically significant. β-TI patients had significantly higher LV T2 values than healthy subjects (56.84 ± 4.03 vs. 52.46 ± 2.50 msec, P < 0.0001) and significantly higher LV T1 values than TM patients (1018.32 ± 48.94 vs. 966.66 ± 66.47 msec, P < 0.0001). In β-TI, female gender was associated with significantly increased LV T1 (P = 0.041) and T2 values (P < 0.0001), while splenectomy and presence of regular transfusions were associated with significantly lower LV T1 values (P = 0.014 and P = 0.001, respectively). In β-TI patients, all LV relaxation times were significantly correlated with each other (T2*-T1: P = 0.003; T2*-T2: P = 0.003; T1-T2: P < 0.0001). Two patients with a reduced LV T2* also had a reduced LV T1, while only one had a reduced LV T2. Three patients had a reduced LV T1 but a normal LV T2*; 66.7% of the patients had an increased LV T2. All LV relaxation times were significantly correlated with pancreas T2* values (T2*: P = 0.033; T1: P < 0.0001; T2: P = 0.014). No LV relaxation time was associated (P > 0.05) with hepatic iron concentration, biventricular function parameters, or LGE presence. The combined use of all three myocardial relaxation times has potential to improve sensitivity in the detection of early/subclinical myocardial involvement in β-Tl patients. 2 TECHNICAL EFFICACY: Stage 2.

Deep Learning Virtual Contrast-Enhanced T1 Mapping for Contrast-Free Myocardial Extracellular Volume Assessment.

The acquisition of contrast-enhanced T1 maps to calculate extracellular volume (ECV) requires contrast agent administration and is time consuming. This study investigates generative adversarial networks for contrast-free, virtual extracellular volume (vECV) by generating virtual contrast-enhanced T1 maps. This retrospective study includes 2518 registered native and contrast-enhanced T1 maps from 1000 patients who underwent cardiovascular magnetic resonance at 1.5 Tesla. Recent hematocrit values of 123 patients (hold-out test) and 96 patients from a different institution (external evaluation) allowed for calculation of conventional ECV. A generative adversarial network was trained to generate virtual contrast-enhanced T1 maps from native T1 maps for vECV creation. Mean and SD of the difference per patient (ΔECV) were calculated and compared by permutation of the 2-sided t test with 10 000 resamples. For ECV and vECV, differences in area under the receiver operating characteristic curve (AUC) for discriminating hold-out test patients with normal cardiovascular magnetic resonance versus myocarditis or amyloidosis were tested with Delong's test. ECV and vECV showed a high agreement in patients with myocarditis (ΔECV: hold-out test, 2.0%±1.5%; external evaluation, 1.9%±1.7%) and normal cardiovascular magnetic resonance (ΔECV: hold-out test, 1.9%±1.4%; external evaluation, 1.5%±1.2%), but variations in amyloidosis were higher (ΔECV: hold-out test, 6.2%±6.0%; external evaluation, 15.5%±6.4%). In the hold-out test, ECV and vECV had a comparable AUC for the diagnosis of myocarditis (ECV AUC, 0.77 versus vECV AUC, 0.76; P=0.76) and amyloidosis (ECV AUC, 0.99 versus vECV AUC, 0.96; P=0.52). Generation of vECV on the basis of native T1 maps is feasible. Multicenter training data are required to further enhance generalizability of vECV in amyloidosis.

CMR native T1 and T2 Mapping in Olympic athletes: the influence of sport discipline and sex

Abstract Background Cardiac Magnetic Resonance (CMR) has a growing role in evaluating athletes’ hearts. Mapping techniques provide added value for tissue characterisation, but data on athletes and sports disciplines are lacking. Aim To describe native mapping values in a cohort of Olympic Athletes and evaluate the influence of sports discipline and sex. Methods A group of 300 Olympic athletes (13% skill, 20% power, 25% mixed, 42% endurance, 58% male) with unremarkable cardiovascular screening and a control group of 42 sedentary subjects (52% male) underwent CMR without contrast administration. Athletes were divided based on sex and sports categories according to the ESC classification. Results Among athletes of different sports categories and controls, endurance presented the lowest value of T1 mapping (p&amp;lt;0.001). No differences in T2 mapping were observed (p=0.472). Female athletes had higher values of T1 native myocardial mapping compared to males (p=0.001), while there were no differences in T2 mapping (p=0.817). Male athletes with higher left ventricular mass indexed (LV-Massi) had lower values of T1 mapping (p=0.006) and slightly higher values of T2 mapping, even if not significant (p=0.150). Female athletes with higher LV-Massi did not show significant differences in T1 and T2 mapping (p=0.053 and p=0.438) Conclusions T1 native myocardial mapping showed significant differences related to sports disciplines and gender. Athletes with the largest LV remodelling, mostly endurance and mixed, showed the lowest values of T1 mapping. Male athletes showed lower values of T1 mapping than females. No significant differences were observed in T2 mapping related to sports disciplines and gender.

No differences in native T1 of the renal cortex between Fabry disease patients and healthy subjects in cardiac dedicated native T1 maps

BackgroundFabry disease (FD) is an X-linked inherited lysosomal storage disease that is caused by deficient activity of the enzyme alpha-galactosidase A. Cardiovascular magnetic resonance (CMR) imaging can detect cardiac sphingolipid accumulation using native T1 mapping. The kidneys are often visible in cardiac CMR native T1 maps, however it is currently unknown if the maps can be used to detect sphingolipid accumulation in the kidneys of FD patients. Therefore, the aim of this study was to evaluate if cardiac dedicated native T1 maps can be used to detect sphingolipid accumulation in the kidneys. MethodsFD patients (n=18, 41 ± 10 years, 44% male) and healthy subjects (n=38, 41 ± 16 years, 47% male) were retrospectively enrolled. Native T1 maps were acquired at 1.5T (MAGNETOM Aera) using MOLLI research sequences. Native T1 values were measured by manually delineating regions of interest (ROI) in the renal cortex, renal medulla, heart, spleen, blood, and liver. Endo- and epicardial borders were delineated in the myocardium and averaged across all slices. Blood ROIs were placed in the left-ventricular blood pool in the midventricular slice. ResultsThere were no differences in native T1 between the FD patients and the healthy subjects in the renal cortex (1034±88 ms vs 1056±59 ms, p=0.29), blood (1614±111 ms vs 1576 ± 100 ms, p=0.22), spleen (1143±45 ms vs 1132±70 ms, p=0.54) or liver (568±49 ms vs 557±47 ms, p=0.41). Native T1 was lower in the hearts of the FD patients compared to healthy subjects (951±79 vs 1006±38, p<0.01), and higher in the renal medulla (1635±144 vs 1514±81, p<0.01). The results were similar when stratified for sex. ConclusionCompared to healthy subjects, patients with FD and cardiac involvement had no differences in native T1 of the renal cortex. FD patients had higher native T1 in the renal medulla, which is not totally explained by differences in blood native T1 but may reflect a hyperfiltration state in the development of renal failure. The findings suggest that sphingolipid accumulation in the renal cortex in FD patients could not be detected with cardiac dedicated research native T1 maps.

Development and performance evaluation of fully automated deep learning-based models for myocardial segmentation on T1 mapping MRI data

To develop a deep learning-based model capable of segmenting the left ventricular (LV) myocardium on native T1 maps from cardiac MRI in both long-axis and short-axis orientations. Models were trained on native myocardial T1 maps from 50 healthy volunteers and 75 patients using manual segmentation as the reference standard. Based on a U-Net architecture, we systematically optimized the model design using two different training metrics (Sørensen-Dice coefficient = DSC and Intersection-over-Union = IOU), two different activation functions (ReLU and LeakyReLU) and various numbers of training epochs. Training with DSC metric and a ReLU activation function over 35 epochs achieved the highest overall performance (mean error in T1 10.6 ± 17.9 ms, mean DSC 0.88 ± 0.07). Limits of agreement between model results and ground truth were from -35.5 to + 36.1 ms. This was superior to the agreement between two human raters (-34.7 to + 59.1 ms). Segmentation was as accurate for long-axis views (mean error T1: 6.77 ± 8.3 ms, mean DSC: 0.89 ± 0.03) as for short-axis images (mean error ΔT1: 11.6 ± 19.7 ms, mean DSC: 0.88 ± 0.08). Fully automated segmentation and quantitative analysis of native myocardial T1 maps is possible in both long-axis and short-axis orientations with very high accuracy.

Quantitative Evaluation of Noncontrast Magnetic Resonance Enterography for Active Inflammation in Crohn Disease Using Native T1 and T2 Mapping.

The aim of this study was to investigate the utility of native T1 and T2 mapping in the bowel to evaluate disease activity in Crohn disease (CD) using endoscopy as the reference standard. This was a prospective study. Magnetic resonance imaging was performed by using a 1.5-T Philips scanner. We used a modified look-locker inversion recovery and a multiecho gradient-spin-echo sequences for single breath-hold native T1 and T2 maps, respectively, for the short-axis image of the intestine, and the measurement at the most severe site was compared with partial Simple Endoscopic Score for Crohn's Disease (pSES-CD, assessed by an expert endoscopist). A pSES-CD ≥ 4 indicated active disease. Statistical analyses were performed using the Student t test, Spearman correlation, and receiver operating characteristic curve analysis. A total of 27 patients (mean age ± standard deviation, 37 ± 18 years; 20 men, 7 women) were included in this study. The native T1 value of active disease was significantly higher than that of inactive disease (1170.8 ± 100.5 milliseconds vs 924.5 ± 95.3 milliseconds; P = 0.018), but the T2 value was not significantly different between active and inactive disease (76.1 ± 7.8 milliseconds vs 69.3 ± 10.9 milliseconds; P = 0.424). A good correlation was found between native T1 value and pSES-CD (ρ = 0.71; P < 0.001) but not between T2 value and pSES-CD (ρ = 0.06; P = 0.790). The area under the receiver operating characteristic curve for differentiating the disease activity was 0.96 (95% confidence interval [CI]: 0.90-1.00) for T1 values and 0.68 (95% confidence interval: 0.41-0.96) for T2 values. Native T1 mapping could be potentially used as a noninvasive method to differentiate disease activity in patients with CD and may be superior to T2 mapping for this purpose.

Diagnostic accuracy of an uncorrected native T1 mapping sequence for liver fibrosis and inflammation in autoimmune hepatitis: a prospective study using histopathology as reference standard.

There is an unmet clinical need for non-invasive imaging biomarkers that could replace liver biopsy in the management of patients with autoimmune hepatitis (AIH). In this study, we sought to evaluate the diagnostic accuracy of a simple uncorrected, non-contrast T1 mapping for detecting fibrosis and inflammation in AIH patients using histopathology as a reference standard. Over 3years, 33 patients with AIH were prospectively studied using a multiparametric liver MRI protocol which included T1 mapping. Biopsies were performed up to 3months before imaging, and a standardized histopathological score for fibrosis (F0-F4) and inflammatory activity (PPA0-4) was used as a reference. Statistical analysis included independent t test, Mann-Whitney U-test, and ROC (receiver operating characteristic) analysis. T1 mapping values were significantly higher in patients with advanced fibrosis (F0-2 vs. F3-4; p < 0.015), significant fibrosis (F0-1 vs. F2-4; p < 0.005), and significant inflammatory activity (PPA 0-1 vs. PPA 2-4 p = 0.048). Moreover, the technique demonstrated a good diagnostic performance in detecting significant (AUC 0.856) and advanced fibrosis (AUC 0.835), as well as significant inflammatory activity (AUC 0.763). A rapid, simple, uncorrected, non-contrast T1 mapping sequence showed satisfactory diagnostic performance in comparison with histopathology for detecting significant tissue inflammation and fibrosis in AIH patients, being a potential non-invasive imaging biomarker for monitoring disease activity in such individuals.

Automatic pipeline for segmentation of LV myocardium on quantitative MR T1 maps using deep learning model and computation of radial T1 and ECV values.

Native T1 mapping is a non-invasive technique used for early detection of diffused myocardial abnormalities, and it provides baseline tissue characterization. Post-contrast T1 mapping enhances tissue differentiation, enables extracellular volume (ECV) calculation, and improves myocardial viability assessment. Accurate and precise segmenting of the left ventricular (LV) myocardium on T1 maps is crucial for assessing myocardial tissue characteristics and diagnosing cardiovascular diseases (CVD). This study presents a deep learning (DL)-based pipeline for automatically segmenting LV myocardium on T1 maps and automatic computation of radial T1 and ECV values. The study employs a multicentric dataset consisting of retrospective multiparametric MRI data of 332 subjects to develop and assess the performance of the proposed method. The study compared DL architectures U-Net and Deep Res U-Net for LV myocardium segmentation, which achieved a dice similarity coefficient of 0.84 ±0.43 and 0.85 ±0.03, respectively. The dice similarity coefficients computed for radial sub-segmentation of the LV myocardium on basal, mid-cavity, and apical slices were 0.77 ±0.21, 0.81 ±0.17, and 0.61 ±0.14, respectively. The t-test performed between ground truth vs. predicted values of native T1, post-contrast T1, and ECV showed no statistically significant difference (p> 0.05) for any of the radial sub-segments. The proposed DL method leverages the use of quantitative T1 maps for automatic LV myocardium segmentation and accurately computing radial T1 and ECV values, highlighting its potential for assisting radiologists in objective cardiac assessment and, hence, in CVD diagnostics.

Abstract Tu101: Measuring Fibrosis Progression in Duchenne Cardiomyopathy Using Cardiac Magnetic Resonance in mice

Introduction: Transthoracic echocardiogram (TTE) is currently the gold standard for measuring cardiac function in mouse models of cardiomyopathy, however, it has its limitations. Challenges include poor acoustic windows, lower reproducibility, larger margin of error, and inability to accurately detect fibrosis. The detection of fibrosis is critical for assessing the severity of cardiac involvement and monitoring disease progression in Duchenne muscular dystrophy (DMD). Cardiac magnetic resonance imaging (CMR) can be used to more accurately measure cardiac function, chamber volumes, and tissue characterization to monitor the progression of fibrosis, including with parametric T1 mapping and late gadolinium enhancement (LGE). In this study, we have used a dystrophic mouse model (D2. mdx ) on the DBA/2J genetic background as a preclinical model of DMD. Hypothesis: We hypothesize that CMR can detect worsening cardiac function and signs of fibrosis in the left ventricle of D2. mdx mice compared to wildtype (DBA) controls. Methods: In a study group of 12 age-matched male mice (8 mdx, 4 DBA), CMR was performed with contrast to determine cardiac function and fibrotic developments in the heart. Results: D2. mdx mice displayed a higher left ventricular end-diastolic volume compared to DBA mice (32.8 ± 3.6 µL vs 27.4 ± 1.5 µL, p &lt; 0.05). Global longitudinal strain was decreased in D2. mdx compared to DBA mice (-11.0 ± 3.5% vs -18.2 ± 2.2%, p &lt; 0.05). Native T1 mapping (Fig 1A) showed significantly higher mean T1 times in D2. mdx mice compared to DBA controls (Fig 1B). LGE in the myocardium of the left ventricle was noted in 6 of 8 of the D2. mdx mice (Fig 1C), but not in DBA mice. Logistic regression modeling showed strong predictive value detecting LGE with increasing native T1 times (Fig 1D). Conclusion: CMR can detect tissue changes in D2. mdx myocardium representing fibrotic changes. Native T1 may be useful in longitudinal studies of antifibrotic therapies in these models.

Enabling Reliable Visual Detection of Chronic Myocardial Infarction with Native T1 Cardiac MRI Using Data-Driven Native Contrast Mapping.

Purpose To investigate whether infarct-to-remote myocardial contrast can be optimized by replacing generic fitting algorithms used to obtain native T1 maps with a data-driven machine learning pixel-wise approach in chronic reperfused infarct in a canine model. Materials and Methods A controlled large animal model (24 canines, equal male and female animals) of chronic myocardial infarction with histologic evidence of heterogeneous infarct tissue composition was studied. Unsupervised clustering techniques using self-organizing maps and t-distributed stochastic neighbor embedding were used to analyze and visualize native T1-weighted pixel-intensity patterns. Deep neural network models were trained to map pixel-intensity patterns from native T1-weighted image series to corresponding pixels on late gadolinium enhancement (LGE) images, yielding visually enhanced noncontrast maps, a process referred to as data-driven native mapping (DNM). Pearson correlation coefficients and Bland-Altman analyses were used to compare findings from the DNM approach against standard T1 maps. Results Native T1-weighted images exhibited distinct pixel-intensity patterns between infarcted and remote territories. Granular pattern visualization revealed higher infarct-to-remote cluster separability with LGE labeling as compared with native T1 maps. Apparent contrast-to-noise ratio from DNM (mean, 15.01 ± 2.88 [SD]) was significantly different from native T1 maps (5.64 ± 1.58; P < .001) but similar to LGE contrast-to-noise ratio (15.51 ± 2.43; P = .40). Infarcted areas based on LGE were more strongly correlated with DNM compared with native T1 maps (R2 = 0.71 for native T1 maps vs LGE; R2 = 0.85 for DNM vs LGE; P < .001). Conclusion Native T1-weighted pixels carry information that can be extracted with the proposed DNM approach to maximize image contrast between infarct and remote territories for enhanced visualization of chronic infarct territories. Keywords: Chronic Myocardial Infarction, Cardiac MRI, Data-Driven Native Contrast Mapping Supplemental material is available for this article. © RSNA, 2024.

Comparison of diagnostic algorithms in clinically suspected viral myocarditis: agreement between cardiac magnetic resonance, endomyocardial biopsy and troponin T

AimsMyocardial inflammation is increasingly detected non-invasively by tissue mapping with cardiovascular magnetic resonance (CMR). Intraindividual agreement with endomyocardial biopsy (EMB) or marker of myocardial injury, high-sensitive troponin (hs-cTnT) in patients with clinically suspected viral myocarditis not understood. Methods and resultsProspective multicentre study of consecutive patients with clinically suspected myocarditis who underwent blood testing for hs-cTnT, CMR and EMB as a part of diagnostic work-up. EMB was considered positive based on immunohistological criteria in line with the ESC definitions. CMR diagnoses employed tissue mapping using sequence-specific cut-off for native T1 and T2 mapping; active inflammation was defined as T1≥2SD and T2≥2SD above the mean of normal range. Hs-cTnT of greater than 13.9ng/1 was considered significant. A total of 114 patients (age (mean±SD) 54±16, 65% males) were included, of which 79(69%) had positive EMB-criteria, 64(56%) CMR criteria, and a total of 58 (51%) positive troponin. Agreement between EMB and CMR diagnostic criteria was poor (CMR vs. ESC: AUCs: 0.51 (0.39-0.62)). The agreement between the significant hs-cTnT rise and CMR-based diagnosis of myocarditis was good (AUC: 0.84 (0.68-0.92); p<0.001), but poor for EMB (0.50 (0.40-0.61). Hs-cTnT was significantly associated with native T1 and T2, hs-CRP and NT-pro BNP (r=0.37, r=0.35, r=0.30, r=0.25 p<0.001), but not immunohistochemical criteria or viral presence. ConclusionsIn clinically suspected viral myocarditis, all diagnostic approaches reflect the pathophysiological elements of myocardial inflammation, however the differing underlying drivers only partially overlap. The EMB and CMR diagnostic algorithms are neither interchangeable in terms of interpretation of myocardial inflammation nor in their relationship with myocardial injury.

The emerging role of cardiovascular magnetic resonance in the evaluation of cardiac involvement in systemic sclerosis

Abstract Systemic sclerosis (SSc) is an autoimmune rheumatic disease, characterized by vascular, inflammatory and fibrotic alterations. Cardiac involvement is the « fatal tip of the iceberg» in SSc, as it leads to high morbidity/mortality. Cardiovascular imaging modalities play an important role in the early diagnosis and treatment assessment of cardiac involvement. Echocardiography is the corner stone for evaluation of cardiac involvement, providing information about function, wall motion, pulmonary pressure, pericardium and valvular disease. It is a low-cost modality, widely available, without radiation and with great experience among cardiologists. However, it is a window and operator dependent modality and cannot provide tissue characterization information, absolutely necessary for diagnosis and treatment of cardiac involvement in SSc. Cardiovascular magnetic resonance (CMR) can perform myocardial function and tissue characterization in the same examination without radiation, has excellent reproducibility and is window and operator independent. The great advantage of CMR is the capability to assess peri- myo-vascular inflammation, myocardial ischemia and presence of replacement and diffuse myocardial fibrosis in parallel with ventricular function assessment. The modified Lake Louise criteria including T2, native T1 mapping and extracellular volume fraction (ECV) has been recently used to diagnose inflammatory cardiomyopathy. According to expert recommendations, myocardial inflammation should be considered if at least 2 indices, one T2 and one T1 parameter are positive, whereas native T1 mapping and ECV assess diffuse fibrosis or oedema, even in the absence of late gadolinium enhancement (LGE). Moreover, transmural/subendocardial LGE following the distribution of coronary arteries and diffuse subendocardial fibrosis not related with epicardial coronary arteries are indicative of epicardial and micro-vascular coronary artery disease, respectively. To conclude, CMR can overcome the limitations of echocardiography by identifying acute/active or chronic myocardial inflammation/fibrosis, ischemia and myocardial infarction using classic and parametric indices in parallel with biventricular function assessment

Cardiac magnetic resonance findings in cardiac amyloidosis.

The purpose of this review is to highlight the increasing importance of cardiac magnetic resonance (CMR) imaging in diagnosing and managing cardiac amyloidosis, especially given the recent advancements in treatment options. This review emphasizes the crucial role of late gadolinium enhancement (LGE) with phase-sensitive inversion recovery (PSIR) techniques in both diagnosing and predicting patient outcomes in cardiac amyloidosis. The review also explores promising new techniques for diagnosing early-stage disease, such as native T1 mapping and ECV quantification. Additionally, it delves into experimental techniques like diffusion tensor imaging, MR elastography, and spectroscopy. This review underscores CMR as a powerful tool for diagnosing cardiac amyloidosis, assessing risk factors, and monitoring treatment response. While LGE imaging remains the current best practice for diagnosis, emerging techniques such as T1 mapping and ECV quantification offer promise for improved detection, particularly in early stages of the disease. This has significant implications for patient management as newer therapeutic options become available for cardiac amyloidosis.

Predictors of lung cancer subtypes and lymph node status in non-small-cell lung cancer: intravoxel incoherent motion parameters and extracellular volume fraction

ObjectiveTo determine the performance of intravoxel incoherent motion (IVIM) parameters and the extracellular volume fraction (ECV) in distinguishing between different subtypes of lung cancer and predicting lymph node metastasis (LNM) status in patients with non-small-cell lung cancer (NSCLC).MethodsOne hundred sixteen patients with lung cancer were prospectively recruited. IVIM, native, and postcontrast T1 mapping examinations were performed, and the T1 values were measured to calculate the ECV. The differences in IVIM parameters and ECV were compared between NSCLC and small-cell lung cancer (SCLC), adenocarcinoma (Adeno-Ca) and squamous cell carcinoma (SCC), and NSCLC without and with LNM. The assessment of each parameter’s diagnostic performance was based on the area under the receiver operating characteristic curve (AUC).ResultsThe apparent diffusion coefficient (ADC), true diffusion coefficient (D), and ECV values in SCLC were considerably lower compared with NSCLC (all p < 0.001, AUC > 0.887). The D value in SCC was substantially lower compared with Adeno-Ca (p < 0.001, AUC = 0.735). The perfusion fraction (f) and ECV values in LNM patients were markedly higher compared with those without LNM patients (p < 0.01, < 0.001, AUC > 0.708).ConclusionIVIM parameters and ECV can serve as non-invasive biomarkers for assisting in the pathological classification and LNM status assessment of lung cancer patients.Critical relevance statementIVIM parameters and ECV demonstrated remarkable potential in distinguishing pulmonary carcinoma subtypes and predicting LNM status in NSCLC.Key PointsLung cancer is prevalent and differentiating subtype and invasiveness determine the treatment course.True diffusion coefficient and ECV showed promise for subtyping and determining lymph node status.These parameters could serve as non-invasive biomarkers to help determine personalized treatment strategies.Graphical

The Role of Magnetic Resonance Imaging in Risk Stratification of Patients with Acute Myocarditis.

Cardiac magnetic resonance (cMRI) is often used to diagnose acute myocarditis (AM). It is also performed after 6 months to monitor myocardial involvement. However, the clinical and predictive relevance of the 6-month cMRI is uncertain. We used cMRI to assess the morphology and heart function of patients with AM, the correlation between left ventricular remodeling and biomarkers of heart dysfunction and myocardial fibrosis, and the involvement of myocardial fibrosis initially and 6 months after the acute episode. We conducted a prospective study of 90 patients with the clinical suspicion of AM, where cMRI was performed within the first week after symptom onset and repeated after 6 months. Non-ischemic late gadolinium enhancement (LGE) was present in 88 (97.7%) patients and mainly involved the septum and inferior wall. cMRI at 6 months was associated with significantly reduced abnormalities of segmental kinetics (p < 0.001), myocardial edema (p < 0.001), presence of LGE (p < 0.05) and LGE mass (p < 0.01), native T1 mapping (p < 0.001), and presence of pericardial collection (p ≤ 0.001). At 6 months, signs of myocardial edema appeared in 34.4% of patients, and a complete cure (absence of edema and LGE) was found in 8.8% of patients. LGE disappeared in 15.2% of patients, and the mean number of myocardial segments involved decreased from 46% to 30%, remaining unchanged in 13% of patients. Patients with LGE without edema had a more severe prognostic condition than those with persistent edema. Patients with increased LGE extension on the control cMRI had a worse prognosis than those with modified or low LGE. The most significant independent predictive parameters for major cardiovascular events (MACEs) were LGE mass (adjusted OR = 1.27 [1.11-1.99], p < 0.001), myocardial edema (OR = 1.70 [1.14-209.3], p < 0.001), and prolonged native T1 (OR = 0.97 [0.88-3.06], p < 0.001). The mid-wall model of LGE and the presence of edema-free LGE were MACE-independent predictors. LGE, myocardial edema, and prolonged native T1 were predictors of MACEs. LGE does not necessarily mean constituted fibrosis in the presence of edema and may disappear over time. LGE without edema could represent fibrosis, whereas the persistence of edema represents active inflammation and could be associated with the residual chance of complete recovery. cMRI should be performed in all patients with AM at 6 months to evaluate progress and prognosis.

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

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