First-pass myocardial perfusion MRI with reduced subendocardial dark-rim artifact using optimized Cartesian sampling.
J Magn Reson Imaging
; 45(2): 542-555, 2017 02.
Article
em En
| MEDLINE
| ID: mdl-27532501
ABSTRACT
PURPOSE:
The presence of subendocardial dark-rim artifact (DRA) remains an ongoing challenge in first-pass perfusion (FPP) cardiac magnetic resonance imaging (MRI). We propose a free-breathing FPP imaging scheme with Cartesian sampling that is optimized to minimize the DRA and readily enables near-instantaneous image reconstruction. MATERIALS ANDMETHODS:
The proposed FPP method suppresses Gibbs ringing effects-a major underlying factor for the DRA-by "shaping" the underlying point spread function through a two-step process 1) an undersampled Cartesian sampling scheme that widens the k-space coverage compared to the conventional scheme; and 2) a modified parallel-imaging scheme that incorporates optimized apodization (k-space data filtering) to suppress Gibbs-ringing effects. Healthy volunteer studies (n = 10) were performed to compare the proposed method against the conventional Cartesian technique-both using a saturation-recovery gradient-echo sequence at 3T. Furthermore, FPP imaging studies using the proposed method were performed in infarcted canines (n = 3), and in two symptomatic patients with suspected coronary microvascular dysfunction for assessment of myocardial hypoperfusion.RESULTS:
Width of the DRA and the number of DRA-affected myocardial segments were significantly reduced in the proposed method compared to the conventional approach (width 1.3 vs. 2.9 mm, P < 0.001; number of segments 2.6 vs. 8.7; P < 0.0001). The number of slices with severe DRA was markedly lower for the proposed method (by 10-fold). The reader-assigned image quality scores were similar (P = 0.2), although the quantified myocardial signal-to-noise ratio was lower for the proposed method (P < 0.05). Animal studies showed that the proposed method can detect subendocardial perfusion defects and patient results were consistent with the gold-standard invasive test.CONCLUSION:
The proposed free-breathing Cartesian FPP imaging method significantly reduces the prevalence of severe DRAs compared to the conventional approach while maintaining similar resolution and image quality. LEVEL OF EVIDENCE 2 J. Magn. Reson. Imaging 2017;45542-555.Palavras-chave
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Doença da Artéria Coronariana
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Processamento de Sinais Assistido por Computador
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Aumento da Imagem
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Artefatos
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Angiografia por Ressonância Magnética
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Endocárdio
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Imagem de Perfusão do Miocárdio
Tipo de estudo:
Diagnostic_studies
/
Risk_factors_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article