T1 mapping for myocardial extracellular volume measurement by CMR: bolus only versus primed infusion technique.
JACC Cardiovasc Imaging
; 6(9): 955-62, 2013 Sep.
Article
em En
| MEDLINE
| ID: mdl-23582361
ABSTRACT
OBJECTIVES:
The aim of this study was to determine the accuracy of the contrast "bolus only" T1 mapping cardiac magnetic resonance (CMR) technique for measuring myocardial extracellular volume fraction (ECV).BACKGROUND:
Myocardial ECV can be measured with T1 mapping before and after contrast agent if the contrast agent distribution between blood/myocardium is at equilibrium. Equilibrium distribution can be achieved with a primed contrast infusion (equilibrium contrast-CMR [EQ-CMR]) or might be approximated by the dynamic equilibration achieved by delayed post-bolus measurement. This bolus only approach is highly attractive, but currently limited data support its use. We compared the bolus only technique with 2 independent standards collagen volume fraction (CVF) from myocardial biopsy in aortic stenosis (AS); and the infusion technique in 5 representative conditions.METHODS:
One hundred forty-seven subjects were studied healthy volunteers (n = 50); hypertrophic cardiomyopathy (n = 25); severe AS (n = 22); amyloid (n = 20); and chronic myocardial infarction (n = 30). Bolus only (at 15 min) and infusion ECV measurements were performed and compared. In 18 subjects with severe AS the results were compared with histological CVF.RESULTS:
The ECV by both techniques correlated with histological CVF (n = 18, r² = 0.69, p < 0.01 vs. r² = 0.71, p < 0.01, p = 0.42 for comparison). Across health and disease, there was strong correlation between the techniques (r² = 0.97). However, in diseases of high ECV (amyloid, hypertrophic cardiomyopathy late gadolinium enhancement, and infarction), Bland-Altman analysis indicates the bolus only technique has a consistent and increasing offset, giving a higher value for ECVs above 0.4 (mean difference ± limit of agreement for ECV <0.4 = -0.004 ± 0.037 vs. ECV >0.4 = 0.040 ± 0.075, p < 0.001).CONCLUSIONS:
Bolus only, T1 mapping-derived ECV measurement is sufficient for ECV measurement across a range of cardiac diseases, and this approach is histologically validated in AS. However, when ECV is >0.4, the bolus only technique consistently measures ECV higher compared with infusion.Palavras-chave
AS; CMR; CVF; ECV; EQ-CMR; HCM; LGE; ROI; ShMOLLI; T1 mapping; aortic stenosis; bolus; cardiac imaging techniques; cardiac magnetic resonance; collagen volume fraction (%); dynamic; equilibrium; equilibrium contrast cardiac magnetic resonance; extracellular space; extracellular volume; extracellular volume fraction; fibrosis; hypertrophic cardiomyopathy; infusion; late gadolinium enhancement; region of interest; shortened modified look-locker inversion recovery
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Cardiomiopatia Hipertrófica
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Imagem Cinética por Ressonância Magnética
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Matriz Extracelular
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Miocárdio
Tipo de estudo:
Prognostic_studies
Limite:
Adult
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Aged
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Aged80
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article