Influence of myocardial fibrosis and blood oxygenation on heart T2* values in thalassemia patients

Meloni, Antonella; Pepe, Alessia; Positano, Vincenzo; Favilli, Brunella; Maggio, Aurelio; Capra, Marcello; Pinto, Carmela Lo; Gerardi, Calogera; Santarelli, Maria Filomena; Midiri, Massimo; Landini, Luigi; Lombardi, Massimo

doi:10.1002/jmri.21704

Cited by 28 publications

(22 citation statements)

References 38 publications

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“…The use of a combined truncation method with image corrections [9, 16, 45] might be considered in future work. Here, local susceptibility artifacts might have influenced T2* heterogeneity even though its presence, after correction, is known to not significantly affect global heart T2* heterogeneity [18, 46]. Another suggestion made in the literature is the use of susceptibility correction [15–18].…”

Section: Discussionmentioning

confidence: 99%

Semi-automated myocardial segmentation of bright blood multi-gradient echo images improves reproducibility of myocardial contours and T2* determination

Triadyaksa

Prakken

Overbosch

et al. 2016

Magn Reson Mater Phy

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ObjectivesEarly detection of iron loading is affected by the reproducibility of myocardial contour assessment. A novel semi-automatic myocardial segmentation method is presented on contrast-optimized composite images and compared to the results of manual drawing.Materials and methodsFifty-one short-axis slices at basal, mid-ventricular and apical locations from 17 patients were acquired by bright blood multi-gradient echo MRI. Four observers produced semi-automatic and manual myocardial contours on contrast-optimized composite images. The semi-automatic segmentation method relies on vector field convolution active contours to generate the endocardial contour. After creating radial pixel clusters on the myocardial wall, a combination of pixel-wise coefficient of variance (CoV) assessment and k-means clustering establishes the epicardial contour for each segment.ResultsCompared to manual drawing, semi-automatic myocardial segmentation lowers the variability of T2* quantification within and between observers (CoV of 12.05 vs. 13.86% and 14.43 vs. 16.01%) by improving contour reproducibility (P < 0.001). In the presence of iron loading, semi-automatic segmentation also lowers the T2* variability within and between observers (CoV of 13.14 vs. 15.19% and 15.91 vs. 17.28%).ConclusionApplication of semi-automatic myocardial segmentation on contrast-optimized composite images improves the reproducibility of T2* quantification.

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Section: Discussionmentioning

confidence: 99%

Semi-automated myocardial segmentation of bright blood multi-gradient echo images improves reproducibility of myocardial contours and T2* determination

Triadyaksa

Prakken

Overbosch

et al. 2016

Magn Reson Mater Phy

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“…Relaxography of excised rat myocardium showed T1 values of 907±77 ms, T2 values of 32±6 ms and T2* values of 32±6 ms [28]. T2 values of 50-60 ms [54] and T2* values of 35±3 ms [55] were measured on healthy volunteers while T2* values of 27±20 ms were measured on patients with myocardial fibrosis [30]. T1 values of 1100±67 ms and 950-1050 ms were measured in vivo on domestic farm pigs [56] and normal volunteers [57-59] respectively.…”

Section: Discussionmentioning

confidence: 99%

“…The T2 fluctuations may reflect hyperemia and tissue cellular edema in accord with the known pathophysiology of ischemic and post-ischemic yet viable muscle [29]. Myocardial fibrosis and blood oxygenation did not seem to influence T2* [30]. The diffusion anisotropy was used to obtain information on the spatial architecture of the musculoskeletal or cardiac muscle, especially the collagen fibber tractography [31-37].…”

Section: Introductionmentioning

confidence: 99%

Multi-parametric MRI as an indirect evaluation tool of the mechanical properties of in-vitrocardiac tissues

Périé

Dahdah

Foudis

et al. 2013

BMC Cardiovasc Disord

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BackgroundEarly detection of heart failure is essential to effectively reduce related mortality. The quantification of the mechanical properties of the myocardium, a primordial indicator of the viability of the cardiac tissue, is a key element in patient’s care. Despite an incremental utilization of multi-parametric magnetic resonance imaging (MRI) for cardiac tissue characteristics and function, the link between multi-parametric MRI and the mechanical properties of the heart has not been established. We sought to determine the parametric relationship between the myocardial mechanical properties and the MR parameters. The specific aim was to develop a reproducible evaluative quantitative tool of the mechanical properties of cardiac tissue using multi-parametric MRI associated to principal component analysis.MethodsSamples from porcine hearts were submitted to a multi-parametric MRI acquisition followed by a uniaxial tensile test. Multi linear regressions were performed between dependent (Young’s modulus E) and independent (relaxation times T1, T2 and T2*, magnetization transfer ratio MTR, apparent diffusion coefficient ADC and fractional anisotropy FA) variables. A principal component analysis was used to convert the set of possibly correlated variables into a set of linearly uncorrelated variables.ResultsValues of 46.1±12.7 MPa for E, 729±21 ms for T1, 61±6 ms for T2, 26±7 for T2*, 35±5% for MTRx100, 33.8±4.7 for FAx10-2, and 5.85±0.21 mm2/s for ADCx10-4 were measured. Multi linear regressions showed that only 45% of E can be explained by the MRI parameters. The principal component analysis reduced our seven variables to two principal components with a cumulative variability of 63%, which increased to 80% when considering the third principal component.ConclusionsThe proposed multi-parametric MRI protocol associated to principal component analysis is a promising tool for the evaluation of mechanical properties within the left ventricle in the in vitro porcine model. Our in vitro experiments will now allow us focused in vivo testing on healthy and infracted hearts in order to determine useful quantitative MR-based biomarkers.

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“…There is a paucity of data regarding late enhancement in patients with chronic anaemia but it has previously been reported in 33% of patients with TM with a predominantly patchy, non-transmural pattern 3. In contrast, only two of a series of 47 patients with sickle cell disease were found to have regional fibrosis using late enhancement 19.…”

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confidence: 99%

“…T2* is a unique, quantifiable CMR parameter (measured in milliseconds) which is shortened in proportion to the level of particulate iron (in the form of haemosiderin) within myocardial cells. Although there are minor effects from deoxygenated blood and fibrosis, these are minimal in comparison with the effect of the iron at clinically relevant levels of myocardial iron overload 3. Low T2* values are associated with decreasing LV ejection fraction and an increased risk of developing heart failure as a result of cardiac iron overload 2…”

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confidence: 99%

Myocardial fibrosis in thalassaemia: recalling the past or telling the future?

Carpenter

Prasad

Pennell

2009

Heart

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Influence of myocardial fibrosis and blood oxygenation on heart T2* values in thalassemia patients

Cited by 28 publications

References 38 publications

Semi-automated myocardial segmentation of bright blood multi-gradient echo images improves reproducibility of myocardial contours and T2* determination

Semi-automated myocardial segmentation of bright blood multi-gradient echo images improves reproducibility of myocardial contours and T2* determination

Multi-parametric MRI as an indirect evaluation tool of the mechanical properties of in-vitrocardiac tissues

Myocardial fibrosis in thalassaemia: recalling the past or telling the future?

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