Diffuse myocardial fibrosis evaluation using cardiac magnetic resonance T1 mapping: sample size considerations for clinical trials

Journal of Cardiovascular Magnetic Resonance

Research

Peter Kellman¹  Nadine Kawel²  Jacquin Jones²  Christopher T Sibley³  Marcelo S Nacif³  David A Bluemke³  Songtao Liu³  Jing Han⁴ 

[1] Laboratory of Cardiac Energetics, National Heart, Lung and Blood Institute, Bethesda, MD, USA;Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD, USA;Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD, USA;Molecular Biomedical Imaging Laboratory, National Institute of Biomedical Imaging and Bioengineering, Bethesda, MD, USA;U.S. Food and Drug Administration, Rockville, MD, USA;

关键词: Partition Coefficient;    Cardiac Magnetic Resonance;    Late Gadolinium Enhancement;    Gadobenate Dimeglumine;    Diffuse Myocardial Fibrosis;   

DOI  :  10.1186/1532-429X-14-90

 received in 2012-08-06, accepted in 2012-12-18,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundCardiac magnetic resonance (CMR) T1 mapping has been used to characterize myocardial diffuse fibrosis. The aim of this study is to determine the reproducibility and sample size of CMR fibrosis measurements that would be applicable in clinical trials.MethodsA modified Look-Locker with inversion recovery (MOLLI) sequence was used to determine myocardial T1 values pre-, and 12 and 25min post-administration of a gadolinium-based contrast agent at 3 Tesla. For 24 healthy subjects (8 men; 29 ± 6 years), two separate scans were obtained a) with a bolus of 0.15mmol/kg of gadopentate dimeglumine and b) 0.1mmol/kg of gadobenate dimeglumine, respectively, with averaged of 51 ± 34 days between two scans. Separately, 25 heart failure subjects (12 men; 63 ± 14 years), were evaluated after a bolus of 0.15mmol/kg of gadopentate dimeglumine. Myocardial partition coefficient (λ) was calculated according to (ΔR1myocardium/ΔR1blood), and ECV was derived from λ by adjusting (1-hematocrit).ResultsMean ECV and λ were both significantly higher in HF subjects than healthy (ECV: 0.287 ± 0.034 vs. 0.267 ± 0.028, p=0.002; λ: 0.481 ± 0.052 vs. 442 ± 0.037, p < 0.001, respectively). The inter-study ECV and λ variation were about 2.8 times greater than the intra-study ECV and λ variation in healthy subjects (ECV:0.017 vs. 0.006, λ:0.025 vs. 0.009, respectively). The estimated sample size to detect ECV change of 0.038 or λ change of 0.063 (corresponding to ~3% increase of histological myocardial fibrosis) with a power of 80% and an alpha error of 0.05 for heart failure subjects using a two group design was 27 in each group, respectively.ConclusionECV and λ quantification have a low variability across scans, and could be a viable tool for evaluating clinical trial outcome.

【 授权许可】

Unknown   
© Liu et al.; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.