scholarly journals Correction to: Systolic modified Look–Locker inversion recovery myocardial T1 mapping improves the accuracy of T1 and extracellular volume fraction measurements of patients with high heart rate or atrial fibrillation

2020 ◽  
Vol 13 (4) ◽  
pp. 414-414
Author(s):  
Hirohiko Shinbo ◽  
Satoshi Tomioka ◽  
Toshihiko Ino ◽  
Keiko Koyama
Keyword(s):  
Atrial Fibrillation ◽  
Heart Rate ◽  
T1 Mapping ◽  
Volume Fraction ◽  
Extracellular Volume ◽  
Extracellular Volume Fraction ◽  
Inversion Recovery ◽  
High Heart Rate ◽  
Myocardial T1

scholarly journals Extracellular volume fraction by T1 mapping predicts omprovement of left ventricular ejection fraction after catheter ablation in patients with non-ischemic cardiomyopathy and atrial fibrillation

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
M Azuma ◽  
S Kato ◽  
S Kodama ◽  
K Hayakawa ◽  
M Kagimoto ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Catheter Ablation ◽  
Myocardial Fibrosis ◽  
T1 Mapping ◽  
Volume Fraction ◽  
Extracellular Volume ◽  
Extracellular Volume Fraction ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Risk Of Death

Abstract Background The Catheter Ablation versus Standard Conventional Therapy in Patients with Left Ventricular Dysfunction and Atrial Fibrillation (CASTLE-AF) trial has shown that the catheter ablation (CA) for atrial fibrillation (AF) significantly reduced the risk of death and hospitalization for heart failure in patients with non-ischemic dilated cardiomyopathy (NIDCM) and AF (N Engl J Med 2018; 378:417–27). In addition, the Catheter Ablation Versus Medical Rate Control in Atrial Fibrillation and Systolic Dysfunction (CAMERA-MRI) study demonstrated that the absence of myocardial fibrosis on late gadolinium enhanced (LGE) magnetic resonance imaging (MRI) is associated with improvement of left ventricular systolic function after CA in NIDCM patients with AF (J Am Coll Cardiol 2017; 70:1949–61). Extracellular volume fraction (ECV) by T1 mapping has emerges as a non-invasive mean to quantify diffuse myocardial fibrosis. Purpose The aim of this study was to compare the predictive value of LGE-MRI and ECV by T1 mapping for the prediction of improvement of LVEF after CA in NIDCM patients. Methods A total of twenty-eight patients with NIDCM and AF (age: 67±10 years; 25 (89%) male; LVEF: 34.1±8.8%) were studied. Using a 1.5T MR scanner and 32 channel cardiac coils, cine MRI, LGE-MRI, pre- and post- T1 mapping images of LV wall at mid-ventricular level (modified Look-Locker inversion recovery sequence) were acquired. Myocardial fibrosis on LGE was defined as area with >5SD signal intensity of normal myocardium. ECV from six segments of mid ventricular level were averaged for each patient. All patients underwent CA for AF, and the improvement of LVEF before and after CA were evaluated by echocardiography. Results All patients restored sinus rhythm after CA at the time of echocardiography. The mean LVEF was 34.1±8.8% before CA and 49.1±12.0% after CA (p<0.001), resulting an improvement of 15.0±11.8%. Significant correlation was found between improvements in LVEF and amount of fibrosis on LGE-MRI (r=−0.40, p=0.034), improvement of LVEF and ECV (r=−0.55, p=0.008). In the ROC analysis, ECV had a higher discriminative ability for the improvement of LVEF after CA compared with amount of fibrosis on LGE-MRI (AUC 0.885 vs 0.650) (Figure). Conclusions In NIDCM patients with AF, ECV by T1 mapping had better predictive ability for improvement of LVEF after CA in comparison to LGE-MRI. ROC curves of ECV and LGE-MRI Funding Acknowledgement Type of funding source: None

scholarly journals Fast calculation software for modified Look-Locker inversion recovery (MOLLI) T1 mapping

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yoon-Chul Kim ◽  
Khu Rai Kim ◽  
Hyelee Lee ◽  
Yeon Hyeon Choe
Keyword(s):  
T1 Mapping ◽  
Volume Fraction ◽  
Extracellular Volume ◽  
Computation Time ◽  
Software Tool ◽  
Extracellular Volume Fraction ◽  
Inversion Recovery ◽  
Least Square ◽  
Post Contrast ◽  
T1 Map

Abstract Background The purpose of this study was to develop a software tool and evaluate different T1 map calculation methods in terms of computation time in cardiac magnetic resonance imaging. Methods The modified Look-Locker inversion recovery (MOLLI) sequence was used to acquire multiple inversion time (TI) images for pre- and post-contrast T1 mapping. The T1 map calculation involved pixel-wise curve fitting based on the T1 relaxation model. A variety of methods were evaluated using data from 30 subjects for computational efficiency: MRmap, python Levenberg–Marquardt (LM), python reduced-dimension (RD) non-linear least square, C++ single- and multi-core LM, and C++ single- and multi-core RD. Results Median (interquartile range) computation time was 126 s (98–141) for the publicly available software MRmap, 261 s (249–282) for python LM, 77 s (74–80) for python RD, 3.4 s (3.1–3.6) for C++ multi-core LM, and 1.9 s (1.9–2.0) for C++ multi-core RD. The fastest C++ multi-core RD and the publicly available MRmap showed good agreement of myocardial T1 values, resulting in 95% Bland–Altman limits of agreement of (− 0.83 to 0.58 ms) and (− 6.57 to 7.36 ms) with mean differences of − 0.13 ms and 0.39 ms, for the pre- and post-contrast, respectively. Conclusion The C++ multi-core RD was the fastest method on a regular eight-core personal computer for pre- or post-contrast T1 map calculation. The presented software tool (fT1fit) facilitated rapid T1 map and extracellular volume fraction map calculations.

scholarly journals P1585 Cardiac magnetic resonance estimated extracellular volume fraction, but not native T1 mapping, detects scar in patients referred for cardiac resynchronization therapy

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
C Kjellstad Larsen ◽  
J Duchenne ◽  
E Galli ◽  
J M Aalen ◽  
E Kongsgaard ◽  
...  
Keyword(s):  
T1 Mapping ◽  
Volume Fraction ◽  
Extracellular Volume ◽  
Extracellular Volume Fraction ◽  
Cardiac Resynchronization ◽  
Diffuse Fibrosis ◽  
Resynchronization Therapy ◽  
Native T1 ◽  
T1 Relaxation ◽  
Contrast Agent Injection

Abstract Funding Acknowledgements The study was supported by Center for Cardiological Innovation Background Myocardial scar burden (focal fibrosis) is associated with poor response to cardiac resynchronization therapy (CRT), and should preferably be detected prior to device implantation. Late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) is considered reference standard for scar detection, but is not available in renal failure. Diffuse fibrosis is assessed by T1 mapping CMR with or without calculation of extracellular volume fraction (ECV). The method is vulnerable to partial volume effects, thus subendocardial tissue is most often not included in mapping analyses. Whether the contrast-free native T1mapping could replace LGE in the preoperative evaluation of patients referred for CRT is unknown. Purpose To investigate if native T1 mapping and calculation of ECV can adequately detect scar in patients referred for CRT. Methods Scar was quantified as percentage segmental LGE in 45 patients (age 65 ± 10 years, 71% male, QRS-width 165 ± 17ms) referred for CRT. In total 720 segments were analyzed, and LGE≥50% was considered transmural scar. T1-mapping before and after contrast agent injection was performed in all patients. ECV was calculated based on the ratio between tissue T1 relaxation change and blood T1 relaxation change after contrast agent injection, corrected for the haematocrit level. The agreement between native T1/ECV and scar was evaluated with receiver operating characteristic (ROC) curves with calculation of area under the curve (AUC) and 95% confidence interval (CI). Results LGE was present in 255 segments, 465 segments were without LGE. Average native T1 in segments with LGE was 1028 ± 88 ms, and 1040 ± 60 ms in segments without LGE (p = 0.16). The corresponding numbers for ECV were 38.7 ± 10.9% and 30.0 ± 4.7%, p < 0.001. Native T1 showed poor agreement to scar independent of scar size (AUC = 0.532, 95% CI 0.485-0.578 for scars of all sizes, and AUC = 0.572, 95% CI 0.495-0.650 for transmural scars). ECV, on the other hand, showed reasonable agreement with scar of all sizes (AUC = 0.777, 95% CI 0.739-0.815), and good agreement with transmural scars (AUC = 0.856, 95% CI 0.811-0.902). (Figure) Conclusion The contrast-free CMR technique T1 mapping does not adequately detect scars in patients referred for CRT. Adding post contrast T1 measurements and calculating ECV improves accuracy, especially for transmural scars. Future studies should investigate if diffuse fibrosis could be predictive of CRT response. Abstract P1585 Figure. Detection of transmural scars

scholarly journals Incremental benefit in correlation with histology of native T1 mapping, partition coefficient and extracellular volume fraction in patients with aortic stenosis

2016 ◽  
Vol 18 (Suppl 1) ◽  
pp. O48
Author(s):  
Vassilis Vassiliou ◽  
Katharina Wassilew ◽  
Tamir Malley ◽  
Claire E Raphael ◽  
Rebecca S Schofield ◽  
...  
Keyword(s):  
Aortic Stenosis ◽  
Partition Coefficient ◽  
T1 Mapping ◽  
Volume Fraction ◽  
Extracellular Volume ◽  
Extracellular Volume Fraction ◽  
Incremental Benefit ◽  
Native T1

scholarly journals Regional left ventricular myocardial T1 and velocity mapping: elevated extracellular volume fraction is associated with altered myocardial velocities

2014 ◽  
Vol 16 (S1) ◽  
Author(s):  
Jeremy D Collins ◽  
Lewis Sommerville ◽  
Daniela Föll ◽  
Patrick Magrath ◽  
Bruce S Spottiswoode ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Extracellular Volume ◽  
Extracellular Volume Fraction ◽  
Left Ventricular ◽  
Velocity Mapping ◽  
Myocardial T1

Extracellular Volume Fraction Evaluated by T1-Mapping Determines Left Ventricular Stiffness and Is Associated with Exercise Capacity in HFpEF Patients

2016 ◽  
Vol 22 (9) ◽  
pp. S200
Author(s):  
Taku Omori ◽  
Kaoru Dohi ◽  
Naoki Fujimoto ◽  
Shiro Nakamori ◽  
Naoto Kumagai ◽  
...  
Keyword(s):  
Exercise Capacity ◽  
T1 Mapping ◽  
Volume Fraction ◽  
Extracellular Volume ◽  
Extracellular Volume Fraction ◽  
Left Ventricular ◽  
Left Ventricular Stiffness
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