title: Analysis of spatiotemporal fidelity in quantitative 3D first-pass perfusion cardiovascular magnetic resonance.
abstract: BACKGROUND
  Whole-heart first-pass perfusion cardiovascular magnetic resonance (CMR) relies on highly accelerated image acquisition. The influence of undersampling on myocardial blood flow (MBF) quantification has not been systematically investigated yet. In the present work, the effect of spatiotemporal scan acceleration on image reconstruction accuracy and MBF error was studied using a numerical phantom and validated in-vivo.
  
  
  METHODS
  Up to 10-fold scan acceleration using k-t PCA and k-t SPARSE-SENSE was simulated using the MRXCAT CMR numerical phantom framework. Image reconstruction results were compared to ground truth data in the k-f domain by means of modulation transfer function (MTF) analysis. In the x-t domain, errors pertaining to specific features of signal intensity-time curves and MBF values derived using Fermi model deconvolution were analysed. In-vivo first-pass CMR data were acquired in ten healthy volunteers using a dual-sequence approach assessing the arterial input function (AIF) and myocardial enhancement. 10x accelerated 3D k-t PCA and k-t SPARSE-SENSE were compared and related to non-accelerated 2D reference images.
  
  
  RESULTS
  MTF analysis revealed good recovery of data upon k-t PCA reconstruction at 10x undersampling with some attenuation of higher temporal frequencies. For 10x k-t SPARSE-SENSE the MTF was found to decrease to zero at high spatial frequencies for all temporal frequencies indicating a loss in spatial resolution. Signal intensity-time curve errors were most prominent in AIFs from 10x k-t PCA, thereby emphasizing the need for separate AIF acquisition using a dual-sequence approach. These findings were confirmed by MBF estimation based on AIFs from fully sampled and undersampled simulations. Average in-vivo MBF estimates were in good agreement between both accelerated and the fully sampled methods. Intra-volunteer MBF variation for fully sampled 2D scans was lower compared to 10x k-t PCA and k-t SPARSE-SENSE data.
  
  
  CONCLUSIONS
  Quantification of highly undersampled 3D first-pass perfusion CMR yields accurate MBF estimates provided the AIF is obtained using fully sampled or moderately undersampled scans as part of a dual-sequence approach. However, relative to fully sampled 2D perfusion imaging, intra-volunteer variation is increased using 3D approaches prompting for further developments.
authors.affiliation: Institute for Biomedical Engineering, University and ETH Zurich, Gloriastrasse 35, 8092, Zurich, Switzerland.
authors.forename: Lukas
authors.identifier: http://orcid.org/0000-0001-8849-1470
authors.initials: L
authors.lastname: Wissmann
authors.affiliation: Institute for Biomedical Engineering, University and ETH Zurich, Gloriastrasse 35, 8092, Zurich, Switzerland.|Department of Cardiology, University Hospital Zurich, Zurich, Switzerland.|Division of Internal Medicine, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Alexander
authors.initials: A
authors.lastname: Gotschy
authors.affiliation: Institute for Biomedical Engineering, University and ETH Zurich, Gloriastrasse 35, 8092, Zurich, Switzerland.
authors.forename: Claudio
authors.initials: C
authors.lastname: Santelli
authors.affiliation: Institute for Biomedical Engineering, University and ETH Zurich, Gloriastrasse 35, 8092, Zurich, Switzerland.
authors.forename: Kerem Can
authors.initials: KC
authors.lastname: Tezcan
authors.affiliation: Department of Cardiology, University Hospital Zurich, Zurich, Switzerland.|Department of Cardiology, RWTH Aachen University, Aachen, Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Hamada
authors.affiliation: Institute for Biomedical Engineering, University and ETH Zurich, Gloriastrasse 35, 8092, Zurich, Switzerland.|Department of Cardiology, University Hospital Zurich, Zurich, Switzerland.|Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Robert
authors.initials: R
authors.lastname: Manka
authors.affiliation: Institute for Biomedical Engineering, University and ETH Zurich, Gloriastrasse 35, 8092, Zurich, Switzerland. kozerke@biomed.ee.ethz.ch.|Division of Imaging Sciences, King's College London, London, UK. kozerke@biomed.ee.ethz.ch.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kozerke
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D003326:Coronary Circulation; D005240:Feasibility Studies; D005583:Fourier Analysis; D064368:Healthy Volunteers; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008955:Models, Cardiovascular; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D055414:Myocardial Perfusion Imaging / Q000295:instrumentation / Q000379:methods*; D009716:Numerical Analysis, Computer-Assisted; D019047:Phantoms, Imaging; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013997:Time Factors; D055815:Young Adult
keywords: 3D-MTF; First-pass myocardial perfusion; Modulation transfer function; Myocardial blood flow; Whole-heart perfusion; k-t PCA; k-t SPARSE-SENSE