Research Presentation Session: Cardiac

RPS 1103 - Evolving cardiac MRI techniques: development and clinical applications

February 29, 16:00 - 17:30 CET

7 min
Blood native T1 time for estimating synthetic haematocrit and extracellular volume: derivation of a conversion formula at 3T
Johannes Schmid, Graz / Austria
Author Block: M. Puseljic, C. Reiter, M. Fuchsjäger, J. Schmid; Graz/AT
Purpose: Cardiac magnetic resonance imaging (CMR) has emerged as a vital tool for characterising cardiac disorders, with T1 mapping offering quantitative insight into myocardial tissue. The aim of the study was to correlate haematocrit (Hct) levels from blood sampling with native T1 times in the left ventricular (LV) blood pool to derive a formula for estimating synthetic Hct levels (Hctsyn) and for calculation of synthetic extracellular volume fraction (ECVsyn).
Methods or Background: In this retrospective analysis, native T1 times in the LV blood pool (T1blood) were correlated with Hct levels from blood sampling within 24 hours (Hct24h) in 250 CMR scans (3T, MOLLI5(3)3), divided into a derivation and validation cohort. A linear regression equation was derived to calculate Hctsyn and ECVsyn, which was then externally validated.
Results or Findings: In the derivation cohort (n=167), Hct24h exhibited a strong association with T1blood (r = -0.711, p < 0.001). The resultant regression equation, Hctsyn = 1/T1blood * 1355.52 - 0.310, enabled calculation of Hctsyn. In the validation cohort (n=83), Hctsyn displayed a good correlation with Hct24h (r = 0.726, p < 0.001). Additionally, ECVsyn, calculated using Hctsyn, demonstrated an excellent correlation with ECV24h (r = 0.940, p < 0.001). Bland-Altman plots confirmed minimal bias in ECVsyn estimation (0.28%).
Conclusion: A formula for estimating Hctsyn from T1blood was derived, enabling the calculation of ECVsyn. This approach offers a non-invasive alternative to blood sampling and demonstrates good agreement with established methods, enhancing the clinical utility of CMR.
Limitations: Applicability of the results to different scanner setups may be limited by variations in scanner and sequence characteristics.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by an ethics committee; internal reference number: 35-324 ex: 22/23.
7 min
A novel approach to measuring synthetic extracellular volume without invasive blood sampling: the sheva-3t cmr study
Cesare Mantini, Chieti / Italy
Author Block: C. Mantini, A. Sorella, V. Di Mascio, G. Bisaccia, M. Foglietta, D. Calvo Garcia, L. D'Angelo, S. Gallina, F. Ricci; Chieti/IT
Purpose: Existing CMR methods for extracellular volume (ECV) measurement necessitate haematocrit level measurements, which can be impractical in clinical settings. We aimed to derive and validate a multiparametric model for synthetic ECV assessment in clinical 3T CMR.
Methods or Background: We recruited 505 consecutive patients undergoing clinical 3T CMR exams with 48-hour haematocrit sampling. Participants were randomly split into derivation (n=405) and validation (n=100) cohorts. Native T1 was measured in both left ventricular (LV) and right ventricular (RV) blood pools. We derived and validated a multiparametric model for synthetic haematocrit estimation, including covariates selected by multivariate linear regression analysis. The conventional ECV was calculated using a standard blood haematocrit value. Synthetic ECVs were obtained from LV and RV T1 values using Fent's equation and from the 4-factor synthetic haematocrit. We assessed the correlation, agreement, accuracy of classification, and trueness between synthetic and conventional ECVs.
Results or Findings: In the derivation cohort, sex, heart rate, and LV and RV native T1 values were selected as independent predictors of haematocrit and built into a 4-factor model. The 4-factor synthetic haematocrit showed better correlation with blood sampling than the LV and RV synthetic haematocrits (R2:0.380; R2:0.341; R2:0.316, respectively). The 4-factor ECV model showed good correlation with conventional ECV, similar to LV and RV ECVs (R2:0.834, R2:0.823, and R2:0.815, respectively), yet yielded the lowest bias (4-factor ECV:-0.024; RV-ECV:-0.162; LV-ECV:-1.067). These findings were confirmed in the validation cohort (4-factor ECV: R2:0.835; bias:-0.26; LV-ECV: R2:0.807; bias:-0.38; RV-ECV: R2:0.777; bias:-1.22).The 4-factor model exhibited substantial agreement (Cohen's kappa: 0.64) and trueness compared with conventional ECV.
Conclusion: The novel 4-factor synthetic model improves precision and trueness for haematocrit and ECV estimation. Our findings support broader utilisation of synthetic ECV in 3T settings, obviating the need for invasive blood sampling while ensuring clinical accuracy and reliability.
Limitations: This was a retrospective singlecentre study.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: No information was provdided by the submitter.
7 min
T1 mapping and extracellular volume for predicting pre-heart failure in children with Duchenne Muscular Dystrophy
Xinyuan Zhang, Chengdu / China
Author Block: X. Zhang, H. Xu, H. Fu, Y-K. Guo; Chengdu/CN
Purpose: Pre-heart failure (pre-HF) is being recognised as an essential stage known to progress to symptomatic HF. However, early detection of HF in Duchenne Muscular Dystrophy (DMD) is difficult due to progressive muscle necrosis, physical inactivity, and lack of awareness of their deteriorating cardiac function. Therefore, our study aimed to investigate the prognostic value of cardiac magnetic resonance (CMR) for pre-HF in children with DMD.‍
Methods or Background: A total of 113 patients with DMD (age 8.0 [7.0, 9.0] years; 111 boys, 98.2%) were included from July 2018 to July 2022. The study outcome was pre-HF. According to the AHA/ACC/HFSA guideline for the management of HF, pre-HF was defined as patients without current or prior symptoms of HF but with evidence of abnormal cardiac biomarkers, functional or structural heart disease. Survival estimates were calculated by Kaplan-Meier curves with the log-rank test.
Results or Findings: During a mean follow-up of 24.2 ± 11.6 months, a total of 34 patients reached pre-HF. Univariate Cox regression analyses and Multivariate stepwise analyses showed that native T1 (hazard ratio [HR]: 1.014, 95% CI: 1.005-1.022; p =0.002) in model 1 and ECV (HR: 1.366, 95% CI: 1.219-1.531; p <0.001) in model 2 had significant prognostic associations with pre-HF. The cut-off value of ECV was 30.1% (AUC: 0.782; sensitivity: 79.4%; specificity: 75.9%). A native T1 cut-off value of 1294.83 ms had a sensitivity of 55.9%, a specificity of 96.2, and an AUC of 0.790. The cut-off value of ECV and native T1 significantly differed between patients with and without pre-HF in both the LGE-positive and -negative groups (all P < 0.001).
Conclusion: T1 mapping and ECV had prognostic value for pre-HF in DMD patients, which provided optimal risk stratification for early cardiac involvement in DMD patients.‍
Limitations: This was a retrospective single centre analysis.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The Institutional Review Boards of our hospital approved this retrospective study.
7 min
Joint bright- and black-blood late gadolinium enhancement and T1-rho mapping for robust myocardial scar imaging
Victor De Villedon De Naide, Pessac / France
Author Block: V. De Villedon De Naide1, M. Stuber2, J. H. Zhang2, K. Narceau1, P. Gut2, V. Nogues1, M. Villegas-Martinez1, H. Cochet1, A. Bustin1; 1Pessac/FR, 2Lausanne/CH
Purpose: Bright-blood sequences are used to retrieve heart anatomy information, while black-blood late gadolinium enhancement has shown potential for scar detection. Contrast-agent-free T1-rho mapping is a promising technology for quantifying cardiomyopathies. The aim of this study is to provide a single sequence that combines the strengths of black-blood scar detection, bright-blood scar localisation, and T1-rho scar quantification.
Methods or Background: The proposed 2D whole-heart SPOT1-rho acquisition is a single-shot breath-held sequence gathering black- and bright-blood images that are averaged for optimal detection and localisation of scarred tissue. For the bright-blood shots, five shots with increasing T1-rho preparation times were acquired, to generate a T1-rho map, for scar quantification.
A phantom (T1MES) experiment was first conducted with PSIR, SPOT, T1-rho mapping and the proposed SPOT1-rho acquisition. The obtained T1-rho values were compared, along with mean signal intensities from bright- and black-blood images. The same sequences were then prospectively tested in two patients with myocardial infarction and one healthy subject using a 1.5T Siemens Aera scanner. 3-slice short-axis images were acquired 15min post-injection of Gadolinium. T1-rho values were measured in both remote and injured myocardial regions.
Results or Findings: In phantom, an excellent correlation was observed between the reference T1-rho values and those obtained using the SPOT1-rho sequence, along with consistent signal intensities. In patients, elevated myocardial T1-rho values were measured in injured areas, closely matching values obtained from the reference T1-rho mapping sequence.
Conclusion: The proposed SPOT1-rho combines bright- and black-blood imaging and T1-rho mapping to enhance scar detection, localisation, and quantification, offering a promising and versatile tool for myocardial assessment in both research and clinical settings.
Limitations: Validation of the SPOT1-rho sequence requires a greater patient cohort, while clinical application of T1-rho mapping is still at an early stage.
Funding for this study: This project was supported by funding from the French National Research Agency under grant agreements Equipex MUSIC ANR-11-EQPX-0030, ANR-22-CPJ2-0009-01, ANR-21-CE17-0034-01, Programme d'Investissements d'Avenir ANR-10-IAHU04-LIRYC. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No101076351).
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: No information provided by the submitter.
7 min
Cardiac magnetic resonance in infarct-like myocarditis: transmural late gadolinium enhancement is associated with long-term outcome
Alexander Isaak, Bonn / Germany
Author Block: A. Isaak, J. Wirtz, D. Kravchenko, N. Mesropyan, U. I. Attenberger, C. Öztürk, S. Zimmer, D. Kütting, J. A. Luetkens; Bonn/DE
Purpose: The aim of this study was to evaluate the prognostic value of cardiac magnetic resonance (CMR) imaging parameters in terms of the occurrence of MACE in patients with infarct-like myocarditis.
Methods or Background: Patients with acute myocarditis confirmed by CMR between 2007 and 2020 were retrospectively identified. Only patients with infarct-like presentation (chest pain and ST-segment elevation on electrocardiogram and/or troponin elevation) were included into analysis. Functional and morphological imaging analyses were performed. Late gadolinium enhancement (LGE) was qualitatively and quantitively assessed. The association between different parameters and the occurrence of major adverse cardiac events (MACE; including cardiovascular death, new onset of acute symptoms or heart failure symptoms, implantation of pacemaker or defibrillators) within 5 years after discharge was tested using a univariable and multivariable Cox regression and Kaplan-Meier analysis.
Results or Findings: 130/345 patients (38%) had infarct-like presentation (mean age, 40±19 years; 97 men, 75%). LGE lesions involved mostly the subepicardium (111/130 patients [85%]; midwall: 45/130 patients [35%]; both subepicardium and midwall: 27/130 patients [21%]). Septal segments were involved in 42/130 patients (32%). Transmural LGE extension was present in 15/130 patients (12%). The median extent of LGE was 7% (IQR, 4-10). Median duration of follow-up was 19.3 months (IQR, 4.5-53), and MACE occurred in 18/130 patients (14%). Univariable Cox regression analyses revealed an association between MACE and both, LGE extent and transmural LGE extension. In multivariable Cox regression analysis, transmural extension of LGE was an independent predictor for MACE (Hazard ratio, 6.34; 95% CI: 2.29, 17.49; P <0.001). Patients with transmural extension of LGE had a shorter event-free time on Kaplan-Meier analysis (mean [95%CI], 136 weeks [70, 198] vs 236 weeks [221, 252]; log rank P <0.001).
Conclusion: Transmural LGE on CMR seems to be associated with long-term occurrence of MACE in infarct-like myocarditis.
Limitations: The retrospective nature of the study was identified as a limitation.
Funding for this study: A.I. was funded by the BONFOR Research Commission of the Medical Faculty Bonn (BONFOR-Forschungskommission der Medizinischen Fakultät Bonn) and by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) under Germany's Excellence Strategy—EXC2151—390873048.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This was a retrospective study.
7 min
Non-invasive diagnosis of pulmonary hypertension: a comparison between MR 4D flow and echocardiography
Gert Reiter, Graz / Austria
Author Block: G. Reiter, C. Reiter, C. Kräuter, E. Kolesnik, D. Scherr, A. Schmidt, M. Fuchsjäger, U. Reiter; Graz/AT
Purpose: MR time-resolved 3-directional phase-contrast (4D flow) imaging allows estimation of mean pulmonary arterial pressure (mPAP) and diagnosis of pulmonary hypertension (PH) from the duration (t_vortex) of vortical blood flow in the main pulmonary artery. The purpose of the study was to investigate the relationship between 4D flow and standard echocardiographic measures for pressure estimation and diagnosis of PH.
Methods or Background: 94 patients were prospectively investigated by transthoracic echocardiography and near-term 3T 4D flow imaging. Echocardiographic evaluation included the measurement of the tricuspid regurgitant jet velocity (TR) and calculation of the tricuspid regurgitant pressure gradient (TRPG). 4D flow data were employed to derive t_vortex and calculate mPAP. The relationship between TRPG and t_vortex was analysed by regression analysis, the agreement on the presence of PH by contingency table analysis.
Results or Findings: A tricuspid jet was identified in 69 patients (73%). For these subjects the relationship between t_vortex and TRPG was well described by a linear model of t_vortex on TRPG (R=0.88). The definitions of PH by mPAP≥25 mmHg and by TR>2.8 m/s for echocardiography were consistent with the linear model and optimised the agreement of 4D flow and echocardiography for diagnosis of PH. The resulting kappa-values were 0.94 for subjects with visible tricuspid jet and 0.90 for all subjects. Using the threshold of mPAP>20 mmHg for diagnosis of PH resulted in the cut-off TR≥2.5 m/s, yielding kappa-values of 0.79 for subjects with visible tricuspid jet and 0.67 for the entire population.
Conclusion: There is a strong relationship between 4D flow and echocardiographic measures for diagnosis of PH. While the old PH-cut-off mPAP≥25 mmHg shows high agreement between 4D flow-based and echocardiographic PH diagnosis, the recently introduced PH-cut-off mPAP>20 mmHg reduces this agreement substantially.
Limitations: There were no invasive measurements.
Funding for this study: Funding for this study was received from the OeNB Anniversary Fund 17934.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the ethics committee of the Medical University of Graz, Austria; ClinicalTrials.gov: NCT01728597, NCT03253835.
7 min
Left ventricular diastolic dysfunction grading from a single MR 4D flow measurement
Clemens Reiter, Graz / Austria
Author Block: C. Reiter, U. Reiter, E. Kolesnik, C. Kräuter, A. Schmidt, D. Scherr, M. Fuchsjäger, G. Reiter; Graz/AT
Purpose: The aim of this study was to evaluate the feasibility of assessing left ventricular (LV) diastolic dysfunction from a single MR 4D flow measurement using the established echocardiographic algorithm.
Methods or Background: 94 prospectively recruited patients underwent echocardiography and nearterm MR whole-heart 4D flow imaging. LV ejection fraction (EF), left atrial volume index (LAVI), early- (E) and late (A) diastolic transmitral velocities, early diastolic myocardial tissue velocity (e'), and tricuspid regurgitation velocity (TR) were determined from echocardiography and used for grading of diastolic dysfunction according to the 2016 ASE/EACVI algorithm. Comparable variables were derived from MR 4D flow: LVEF and LAVI were evaluated from multiplanar reformatted magnitude images. E, A and e' were analysed from 4D flow velocity fields, and mean pulmonary arterial pressure (mPAP) was assessed from duration of vortex in the main pulmonary artery. LV diastolic dysfunction was graded according to the same algorithm as in echocardiography. Relationships between echocardiographic and 4D flow parameters were analysed by correlation analysis, the agreement for grading between modalities for LV diastolic dysfunction was investigated by contingency table analysis.
Results or Findings: LV diastolic dysfunction of grade 0, indeterminate, grade I, grade II and grade III were found in 51, 9, 13, 13 and 8 subjects by echocardiography. All volumetric and velocity parameters from MR and echocardiography correlated strongly (r=0.75-0.92). In cases where TR was assessable with echocardiography, a strong correlation to MR-derived mPAP was found (r=0.81). Using cut-offs of LAVI >50 ml/m2 and mPAP >25mmHg, there was excellent agreement between 4D flow and echocardiographic grading of diastolic dysfunction with a weighted kappa of 0.85.
Conclusion: The assessment of left ventricular diastolic function from a single 4D flow measurement is possible with excellent agreement to echocardiography.
Limitations: This was a single-centre study.
Funding for this study: Funding was received from the OeNB Anniversary Fund 17934.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by an ethics committee; ClinicalTrials.gov, NCT01728597 & ClinicalTrials.gov, NCT03253835.
7 min
Quantitative perfusion CMR with adenosine for the assessment of coronary microvascular disease in heart failure with preserved ejection fraction patients
Ana Ezponda Casajus, Pamplona / Spain
Author Block: A. Ezponda Casajus1, C. Mbongo1, P. Kellman2, A. González Miqueo1, G. Bastarrika Alemañ1; 1Pamplona/ES, 2Bethseda, MD/US
Purpose: Coronary microvascular disease (CMD) is a main mechanism in the development of diastolic dysfunction, a condition frequently observed in heart failure with preserved ejection fraction (HFpEF) patients. Quantitative stress perfusion cardiovascular magnetic resonance (CMR) is a useful non-invasive technique for the assessment of CMD. The aim of our study was to compare myocardial perfusion reserve (MPR) and myocardial blood flow (MBF) values by using an adenosine stress/rest quantitative perfusion CMR protocol in stage-B (asymptomatic with known risk factors and diastolic dysfunction) and stage-C (with signs and symptoms) HFpEF patients.
Methods or Background: Between December 2021 and November 2022, 39 HFpEF patients (23 in stage-B and 16 in C) underwent quantitative CMR with adenosine for the assessment of CMD. None of the patients had a prior history of severe CAD. Global MBF during rest, stress and MPR indices were calculated using automated pixelwise quantitative myocardial perfusion mapping. Demographics and cardiovascular disorders and risk factors were recorded for the different groups of the HFpEF cohort.
Results or Findings: Stage-B and stage-C patients do not present statistically significant differences in cardiovascular risk factors nor in prior medical history. Stage-C patients were significantly older than stage B patients (76.8n ±5.2 vs 67.1 ±8.4 years old, p <0.001). Stage-C HFpEF patients presented a significantly lower median of global MPR compared to stage B HFpEF patients (2.31, IQR 1.72-2.74 vs 3.20, IQR 2.80-3.55; p =0,004). Regarding stress perfusion values, global median endocardial BF was also significantly lower in patients at stage C (1.60, IQR 1.22-2.05 vs 2.23, IQR 1.66-2.55; p =0,044). There were no significant differences in rest MBF values between groups.
Conclusion: Stage-C HFpEF patients present significant lower values of non-invasive biomarkers of MCD evaluated with quantitative perfusion CMR, than asymptomatic HFpEF patients.
Limitations: No limitations were identified.
Funding for this study: CRUCIAL (H2020): this project has received funding from the SESAR Joint Undertaking under the European Union's Horizon 2020 research and innovation programme under grant agreement No 848109.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the ethics committee of the Clínica Universidad de Navarra.
7 min
Residual myocardial hyperaemia in regadenoson stress/rest quantitative perfusion CMR
Ana Ezponda Casajus, Pamplona / Spain
Author Block: A. Ezponda Casajus, C. Mbongo, M. B. Barrio Piqueras, M. R. López de la Torre Carretero, P. Kellman, M. Vidorreta Díaz de Cerio, G. Bastarrika Alemañ; Pamplona/ES
Purpose: Regadenoson is a recently introduced vasodilator for stress CMR that possesses a relatively long half-life. As this fact may impact myocardial blood flow (MBF) and myocardial perfusion reserve (MPR) estimated when quantitative stress/rest CMR perfusion is performed, this study sought to investigate the presence of residual myocardial hyperaemia on the recovery phase in patients undergoing stress CMR.
Methods or Background: Fifty patients with clinical indication for stress CMR underwent quantitative perfusion imaging in resting conditions, after regadenoson-induced hyperaemia (400 mcg, 5 mL), and 10 minutes after recovery with aminophylline. A total dose of 0.15 mmol/kg of Gadobutrol was administered. Studies showing late gadolinium enhancement (LGE) were excluded. Global myocardial blood flow during rest (MBF-rest), stress (MBF-stress) and recovery (MBF-recov) and MPR indices (MPR-rest and MPR-recov) were calculated using automated pixel-wise quantitative myocardial perfusion mapping.
Results or Findings: A total of 33 patients (25 male, mean age of 61.4 ±2.2 years) were included in the analysis. Seventeen studies showing LGE (15 transmural, 2 subendocardial) were excluded. Global MBF-rest and MBF-stress were 0.81 ±0.26 and 2.11 ±0.73, respectively. After recovery with aminophylline, myocardial perfusion did not return to the resting values (MBF-recov of 0.91 ±0.33) and statistically differed from MBF-rest (P <0.01), suggesting residual myocardial hyperaemia. This resulted in an abnormally low MPR-recov (2.51 ±0.85) with respect to MPR-rest (2.68 ±0.93) (P <0.01).
Conclusion: Despite the use of aminophylline to reverse the vasodilator effect, MBF does not return to resting values and MBF-recov cannot be used as a substitute for MBF-rest when regadenoson is used. Consequently, a rest/stress protocol is advised for quantitative CMR perfusion to obtain accurate MBF and MPR parameters.
Limitations: This study has included a reduced number of participants.
Funding for this study: No funding has been received for this study.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: No information provided by the submitter.
7 min
spCMR as a predictor validity for MACE
Pierpaolo Palumbo, L'Aquila / Italy
Author Block: P. Palumbo, D. Boccetti, S. Lamja, A. Barile, E. Di Cesare; L'Aquila/IT
Purpose: The aim of our study is to analyse the impact of stress perfusion CMR on the management of patients with known or suspected angina CAD.
Methods or Background: Coronary Artery disease (CAD) is a much-discussed topic because of its burden on healthcare systems and patients' quality of life. However, there is still debate about the best strategy to control angina symptoms and to reduce future events.
This was a historical, prospective study. 164 patients with known or suspected CAD who underwent 3.0-T stress CMR were enrolled (22 F, 142 M; mean age 65.9 years CI 95% 64.67-67.11).
We recorded all clinical information including angina symptoms and all major cardiac events (MACE) occurred during the follow-up, including cardiovascular death, arrhythmias and acute myocardial infarction. All therapeutic strategies adopted from clinicians were collected.
Results or Findings: Mean follow-up was 2.8 years (IQ range 0.9-3.9). During the follow up 52 patients reported MACE (32%), while 70 patients showed modification of angina symptoms (43 patients reported improvement of symtoms).
In spite of the way angina symptoms developed, none of the therapeutic strategies analysed were advantageous in angina improvement.
Ischaemia shows a high stratification validity for clinical evolution in IHD patients (OR 2.18, 95%CI 1.12-4.26; P-value 0.022). among therapeutic strategies, only revascularisation showed a significant impaction on MACE occurrence (OR 0.28 P-value 0.016).
Conclusion: IHD is a dynamic disease. CMR-derived ischaemia revealed a good prediction validity for MACE occurrence and adequate therapeutic strategies should be oriented on spCMR stratification.
Limitations: The number of patients, time of follow-up as well as the retrospective nature of the study were identified as limitations.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: This is a retrospective study.

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