Premium
Creatine kinase rate constant in the human heart measured with 3 D ‐localization at 7 tesla
Author(s) -
Clarke William T.,
Robson Matthew D.,
Neubauer Stefan,
Rodgers Christopher T.
Publication year - 2017
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.26357
Subject(s) - flip angle , nuclear magnetic resonance , physics , creatine kinase , amplitude , saturation (graph theory) , monte carlo method , creatine , phosphocreatine , magnetic resonance imaging , voxel , chemistry , mathematics , medicine , optics , statistics , combinatorics , energy metabolism , biochemistry , radiology
Purpose We present a new Bloch‐Siegert four Angle Saturation Transfer (BOAST) method for measuring the creatine kinase (CK) first‐order effective rate constant k f in human myocardium at 7 tesla (T). BOAST combines a variant of the four‐angle saturation transfer (FAST) method using amplitude‐modulated radiofrequency pulses, phosphorus Bloch‐SiegertB 1 + ‐mapping to determine the per‐voxel flip angles, and nonlinear fitting to Bloch simulations for postprocessing. Methods Optimal flip angles and repetition time parameters were determined from Monte Carlo simulations. BOAST was validated in the calf muscle of two volunteers at 3T and 7T. The myocardial CK forward rate constant was then measured in 10 volunteers at 7T in 82 min (after 1 H localization). Results BOASTk f CKvalues were 0.281 ± 0.002 s −1 in the calf and 0.35 ± 0.05 s −1 in myocardium. These are consistent with literature values from lower fields. Using a literature values for adenosine triphosphate concentration, we computed CK flux values of 4.55 ± 1.52 mmol kg −1 s −1 . The sensitive volume for BOAST depends on the B 1 inhomogeneity of the transmit coil. Conclusion BOAST enables measurement of the CK rate constant in the human heart at 7T, with spatial localization in three dimensions to 5.6 mL voxels, using a 10‐cm loop coil. Magn Reson Med 78:20–32, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.