title: First-pass myocardial perfusion MRI with reduced subendocardial dark-rim artifact using optimized Cartesian sampling.
abstract: 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.
  
  
  
  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.
  
  
  
  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.
  
  
  
  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.
  
  
  
  2 J. Magn. Reson. Imaging 2017;45:542-555.
authors.affiliation: Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.|Department of Bioengineering, University of California, Los Angeles, California, USA.
authors.forename: Zhengwei
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Siemens Healthcare, Los Angeles, California, USA.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Bi
authors.affiliation: Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.|Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA.|Cedars-Sinai Heart Institute, Los Angeles, California, USA.
authors.forename: Janet
authors.initials: J
authors.lastname: Wei
authors.affiliation: Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.|Department of Bioengineering, University of California, Los Angeles, California, USA.
authors.forename: Hsin-Jung
authors.initials: HJ
authors.lastname: Yang
authors.affiliation: Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.|Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA.|Cedars-Sinai Heart Institute, Los Angeles, California, USA.
authors.forename: Rohan
authors.initials: R
authors.lastname: Dharmakumar
authors.affiliation: Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.|Cedars-Sinai Heart Institute, Los Angeles, California, USA.
authors.forename: Reza
authors.initials: R
authors.lastname: Arsanjani
authors.affiliation: Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA.|Cedars-Sinai Heart Institute, Los Angeles, California, USA.
authors.forename: C Noel
authors.initials: CN
authors.lastname: Bairey Merz
authors.affiliation: Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.|Department of Bioengineering, University of California, Los Angeles, California, USA.|Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA.
authors.forename: Debiao
authors.initials: D
authors.lastname: Li
authors.affiliation: Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.|Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA.
authors.forename: Behzad
authors.initials: B
authors.lastname: Sharif
mesh_terms: D000465:Algorithms; D000818:Animals; D016477:Artifacts; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D004285:Dogs; D004699:Endocardium / Q000000981:diagnostic imaging*; D005260:Female; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D015203:Reproducibility of Results; D018401:Sample Size; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
keywords: Gibbs ringing; dark rim artifact; first pass perfusion; ischemic heart disease; myocardial perfusion; subendocardial ischemia