scholarly journals Native T1 Relaxation Time and Extracellular Volume Fraction as Accurate Markers of Diffuse Myocardial Fibrosis in Heart Valve Disease　– Comparison With Targeted Left Ventricular Myocardial Biopsy –

2016 ◽  
Vol 80 (5) ◽  
pp. 1202-1209 ◽  
Author(s):  
Radka Kockova ◽  
Petr Kacer ◽  
Jan Pirk ◽  
Jiri Maly ◽  
Lucie Sukupova ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Volume Fraction ◽  
Extracellular Volume ◽  
Extracellular Volume Fraction ◽  
Left Ventricular ◽  
Diffuse Myocardial Fibrosis ◽  
Heart Valve Disease ◽  
Myocardial Biopsy ◽  
T1 Relaxation Time ◽  
T1 Relaxation

scholarly journals Extracellular volume quantification using synthetic haematocrit assessed from native and post-contrast longitudinal relaxation T1 times of a blood pool

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lukas Opatril ◽  
Roman Panovsky ◽  
Jan Machal ◽  
Tomas Holecek ◽  
Lucia Masarova ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Volume Fraction ◽  
Extracellular Volume ◽  
Relaxation Times ◽  
Extracellular Volume Fraction ◽  
Blood Pool ◽  
Coefficient Of Determination ◽  
Post Contrast ◽  
T1 Relaxation ◽  
Before And After

Abstract Background In terms of cardiovascular magnetic resonance are haematocrit values required for calculation of extracellular volume fraction (ECV). Previously published studies have hypothesized that haematocrit could be calculated from T1 blood pool relaxation time, however only native T1 relaxation time values have been used and the resulting formulae had been both in reciprocal and linear proportion. The aim of the study was to generate a synthetic haematocrit formula from only native relaxation time values first, calculate whether linear or reciprocal model is more precise in haematocrit estimation and then determine whether adding post-contrast values further improve its precision. Methods One hundred thirty-nine subjects underwent CMR examination. Haematocrit was measured using standard laboratory methods. Afterwards T1 relaxation times before and after the application of a contrast agent were measured and a statistical relationship between these values was calculated. Results Different linear and reciprocal models were created to estimate the value of synthetic haematocrit and ECV. The highest coefficient of determination was observed in the combined reciprocal model “− 0.047 + (779/ blood native) − (11.36/ blood post-contrast)”. Conclusions This study provides more evidence that assessing synthetic haematocrit and synthetic ECV is feasible and statistically most accurate model to use is reciprocal. Adding post-contrast values to the calculation was proved to improve the precision of the formula statistically significantly.

Abstract 13596: Magnetic Resonance - Derived Pre-contrast T1 Relaxation Time is the Accurate Marker of Diffuse Myocardial Fibrosis in Severe Aortic Valve Disease: A Comparison With Left Ventricular Myocardial Biopsy

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Radka Kockova ◽  
Petr Kacer ◽  
Jan Pirk ◽  
Jiri Maly ◽  
Martina Vsianska ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Myocardial Fibrosis ◽  
T1 Mapping ◽  
Interventricular Septum ◽  
Left Ventricular ◽  
Diffuse Myocardial Fibrosis ◽  
T1 Relaxation Time ◽  
Native T1 ◽  
T1 Relaxation ◽  
Myocardial Collagen

Introduction: Diffuse myocardial fibrosis (DFM) is the major mechanism in the pathophysiology of the aortic stenosis and its complications. DMF is detectable by magnetic resonance imaging (MRI) using the T1 mapping technique. Hypothesis: The MRI derived native T1 relaxation time and myocardial extracellular volume fraction (ECV) will be significantly related to the extent of DMF et targeted myocardial left ventricular (LV) biopsy. Methods: The study population consisted of 40 consecutive patients (age 63±8y, 65% males) undergoing surgery for severe aortic stenosis (77.5%), aortic root dilatation (7.5%) or valve regurgitation (15%). All patients underwent MRI-derived T1 mapping and 2D-, 3D speckle tracking-derived strain analysis prior to surgery. The T1 relaxation time was assessed in basal interventricular septum pre and 10 min post contrast administration using the modified Look-Locker Inversion recovery sequence. A LV myocardial biopsy specimen was obtained during surgery from basal interventricular septum under the guidance of the MRI operator to assure spatial concordance with the MRI assessment. The percentage of myocardial collagen was quantified as a ratio of Picrosirius Red-positive area over total sample area using the Image J. Results: The average percentage of myocardial collagen was 22 ± 14.8 %. The average native T1 relaxation time and ECV was 1010 ± 48 ms and 0.288 ± 0.055, respectively. Both native T1 relaxation time with cutoff value of ≥ 1010 ms (Ss=90%, Sp=73%, AUC =0.82) and ECV with cutoff value of ≥ 0.315 (Ss=80%, Sp=90%, AUC =0.85) showed high accuracy to identify extensive (> 30%) myocardial collagen content (Figure 1A, 1B). The native T1 mapping showed significant correlation with LV mass, 2D and 3D global longitudinal strain (all p<0.05) while the ECV did not (p=NS). Conclusions: Native T1 relaxation time is the accurate marker of diffuse myocardial fibrosis with the significant relationship with LV morphology and myocardial function.

scholarly journals Extracellular Volume Quantification using Synthetic Haematocrit Assessed from Native and Post-contrast Longitudinal Relaxation T1 Times of a Blood Pool

2021 ◽  
Author(s):  
Lukas Opatril ◽  
Roman Panovsky ◽  
Jan Machal ◽  
Tomas Holecek ◽  
Lucia Masarova ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Volume Fraction ◽  
Extracellular Volume ◽  
Relaxation Times ◽  
Extracellular Volume Fraction ◽  
Blood Pool ◽  
Coefficient Of Determination ◽  
Post Contrast ◽  
T1 Relaxation ◽  
Before And After

Abstract Background: In terms of cardiovascular magnetic resonance are haematocrit values required for calculation of extracellular volume fraction (ECV). Previously published studies have hypothesized that haematocrit could be calculated from T1 blood pool relaxation time, however only native T1 relaxation time values have been used and the resulting formulae had been both in reciprocal and linear proportion. The aim of the study was to generate a synthetic haematocrit formula from only native relaxation time values first, calculate whether linear or reciprocal model is more precise in haematocrit estimation and then determine whether adding post-contrast values further improve its precision.Methods: One hundred thirty-nine subjects underwent CMR examination. Haematocrit was measured using standard laboratory methods. Afterwards T1 relaxation times before and after the application of a contrast agent were measured and a statistical relationship between these values was calculated.Results: Different linear and reciprocal models were created to estimate the value of synthetic haematocrit and ECV. The highest coefficient of determination was observed in the combined reciprocal model “-0.047 + (779/ blood native) – (11.36/ blood post-contrast)”.Conclusions: This study provides more evidence that assessing synthetic haematocrit and synthetic ECV is feasible and statistically most accurate model to use is reciprocal. Adding post-contrast values to the calculation was proved to improve the precision of the formula statistically significantly.

scholarly journals The link between left ventricular extracellular volume determined by T1 myocardial mapping and gut microbiota composition in individuals with heart failure and preserved ejection fraction

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A.N Kaburova ◽  
O.M Drapkina ◽  
S.M Uydin ◽  
M.V Vishnyakova ◽  
M.S Pokrovskaya ◽  
...  
Keyword(s):  
Heart Failure ◽  
Ejection Fraction ◽  
Gut Microbiota ◽  
Myocardial Fibrosis ◽  
Volume Fraction ◽  
Extracellular Volume ◽  
Left Ventricular ◽  
Diffuse Myocardial Fibrosis ◽  
Rrna Gene ◽  
Preserved Ejection Fraction

Abstract Introduction Heart failure with preserved ejection fraction (HFpEF) represents a major challenge in modern cardiology. As described previously, in HFpEF comorbidities promote a systemic inflammatory state, leading to diffuse myocardial fibrosis resulting in myocardial stiffening. Gut dysbiosis which is considered as the novel source of chronic systemic inflammation has been actively investigated as the risk factor for the development and aggravation of cardiovascular diseases including heart failure. Cardiac magnetic resonance T1-mapping is a novel tool, which allows noninvasive quantification of the extracellular space and diffuse myocardial fibrosis. Moreover, the extracellular volume (ECV) fraction can be calculated, providing information on the relative expansion of the extracellular matrix, thus being a noninvasive alternative to myocardial biopsy studies. Purpose The research was aimed at investigating the correlation between the left ventricular ECV and gut microbial genera in patients with HFpEF. Methods 42 patients with confirmed HF-pEF (mediana and interquartile range of age 67 [64; 72] years, 47% men, body mass index &lt;35 kg/m2 with no history of myocardial infarction or diabetes mellitus) were enrolled in the study. The patients underwent transthoracic echocardiography with Doppler study, HF-pEF was confirmed according to the recent ESC guidelines (based on E/e' ratio, N-terminal pro-B type natriuretic peptide &gt;125 pg/ml and symptoms of heart failure). The intestinal microbiome was investigated using high-throughput sequencing of bacterial 16S rRNA gene. As the last step of research T1-myocardial mapping with the modified look-locker inversion-recovery protocol (MOLLI) sequence at 1.5 Tesla was performed to assess left ventricular extracellular volume fraction. Results The mean±std in ECV was 31.02±4.4%. The relative abundance (%) of the most prevalent phyla in gut microbiota was 48±22.5 for Firmicutes, 47.4±22.8 for Bacteroidetes and 1.5 [1.5; 2.5] for Proteobacteria. The analysis showed significant negative correlations between ECV and the following bacterial genera: Faecalibacterium (r=−0.35), Blautia (r=−0.43), Lachnoclostridium (r=−0.32). Moreover ECV positively correlated with Holdemania (r=0.4), Victivallis (r=0.38), Dehalobacterium (r=0.38), Enterococcus (r=0.33) and Catabacter (r=0.32). All correlation values with p&lt;0.05. Conclusion We discovered both negative and positive significant correlations between ECV – the non-invasive marker of myocardial fibrosis and several bacterial genera, which may have negative impact on myocardial remodeling in HF-pEF. Funding Acknowledgement Type of funding source: None

Transmural heterogeneity of diffusion anisotropy in the sheep myocardium characterized by MR diffusion tensor imaging

2007 ◽  
Vol 293 (4) ◽  
pp. H2377-H2384 ◽  
Author(s):  
Yi Jiang ◽  
Julius M. Guccione ◽  
Mark B. Ratcliffe ◽  
Edward W. Hsu
Keyword(s):  
Diffusion Tensor Imaging ◽  
Volume Fraction ◽  
Diffusion Tensor ◽  
Extracellular Volume ◽  
Extracellular Volume Fraction ◽  
Left Ventricular ◽  
Fiber Direction ◽  
Significant Difference ◽  
Mr Diffusion ◽  
Mr Diffusion Tensor Imaging

The orientation of MRI-measured diffusion tensor in the myocardium has been directly correlated to the tissue fiber direction and widely characterized. However, the scalar anisotropy indexes have mostly been assumed to be uniform throughout the myocardial wall. The present study examines the fractional anisotropy (FA) as a function of transmural depth and circumferential and longitudinal locations in the normal sheep cardiac left ventricle. Results indicate that FA remains relatively constant from the epicardium to the midwall and then decreases (25.7%) steadily toward the endocardium. The decrease of FA corresponds to 7.9% and 12.9% increases in the secondary and tertiary diffusion tensor diffusivities, respectively. The transmural location of the FA transition coincides with the location where myocardial fibers run exactly circumferentially. There is also a significant difference in the midwall-endocardium FA slope between the septum and the posterior or lateral left ventricular free wall. These findings are consistent with the cellular microstructure from histological studies of the myocardium and suggest a role for MR diffusion tensor imaging in characterization of not only fiber orientation but, also, other tissue parameters, such as the extracellular volume fraction.

Abstract 17263: Pre-Clinical Left Ventricular Myocardial Remodeling in Patients With Friedreich’s Ataxia: A Cardiac MRI Study

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_1) ◽  
Author(s):  
Karen A Takazaki1 ◽  
Thiago Quinaglia A. C. Silva ◽  
Alberto Martinez ◽  
Tomas Neilan ◽  
Ravi SHAH ◽  
...  
Keyword(s):  
Heart Failure ◽  
Volume Fraction ◽  
Extracellular Volume ◽  
Extracellular Volume Fraction ◽  
Friedreich’S Ataxia ◽  
Left Ventricular ◽  
Friedreich's Ataxia ◽  
Intracellular Water ◽  
Lv Mass ◽  
Burn Out

Background: Heart Failure (HF) is the most common cause of death in Friedreich’s ataxia (FRDA), an inherited mitochondrial disease. Myocardial fibrosis is a well-documented histopathological feature among FRDA patients with HF. Objectives: In this study we will investigate the myocardial extracellular volume fraction (ECV) and intracellular water lifetime (τ ic ), using T1-weighted CMR imaging, in a cohort of patients with FRDA without signs of heart failure. We will also investigate whether myocardial tissue phenotyping by CMR can highlight particular characteristics of LV remodeling in FRDA’s cardiomyopathy, beyond those currently assessed with imaging-based classification of disease severity. Methods: Twenty-six FRDA’s patients (age 26.6±9.3 years, 15 women) without signs of HF, and 10 healthy controls (32.6±7.3 years, 5 women) underwent cardiac magnetic resonance (CMR) studies for assessment of left ventricular (LV) function, myocardial T1, late gadolinium enhancement (LGE), extracellular volume fraction (ECV), and intracellular water-lifetime (τ ic ) as marker of cardiomyocyte size. Neurological decline was determined using the FRDA rating scale (FARS 3). Results: FRDA patients had normal LV ejection fraction (LVEF: 67.66±11.4 vs. 63.9±9.0, P=0.311), larger LV mass index (LVMASSi: 61.03±22.1 vs. 45±4.2g/m 2 , P<0.001), and decreased LV end-diastolic volume index (LVEDVi 53.42±12 vs. 75.7±16.1, P=0.002), compared with controls. ECV and τ ic , were increased in FRDA patients (ECV: 0.36±0.05 vs. 0.25±0.02, P<0.0001; τ ic : 0.13±0.07 vs. 0.06±0.03, P=0.001). ECV was positively associated with LV mass-to-volume ratio (r=0.628, P<0.001). FARS 3 correlated positively with disease duration (r=0.669, P<0.001), and negatively with τ ic , (r=0.478, P=0.039). LVMASSi and cardiomyocyte mass-index [(1–ECV)LVMASSi] declined with age, indicating that LV hypertrophy may transition to a “burn-out” phase with LV atrophy. Conclusions: LV hypertrophy in FRDA reflects an expansion of the myocardial interstitium and an increase in cardiomyocyte size. In contrast, the neurological decline was more likely with decreasing cardiomyocyte size, possibly an early sign of myocardial “burn-out” in FRDA.

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 &lt; 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

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