title: Matrix-algebra-based calculations of the time evolution of the binary spin-bath model for magnetization transfer.
abstract: Quantification of magnetization-transfer (MT) experiments are typically based on the assumption of the binary spin-bath model. This model allows for the extraction of up to six parameters (relative pool sizes, relaxation times, and exchange rate constants) for the characterization of macromolecules, which are coupled via exchange processes to the water in tissues. Here, an approach is presented for estimating MT parameters acquired with arbitrary saturation schemes and imaging pulse sequences. It uses matrix algebra to solve the Bloch-McConnell equations without unwarranted simplifications, such as assuming steady-state conditions for pulsed saturation schemes or neglecting imaging pulses. The algorithm achieves sufficient efficiency for voxel-by-voxel MT parameter estimations by using a polynomial interpolation technique. Simulations, as well as experiments in agar gels with continuous-wave and pulsed MT preparation, were performed for validation and for assessing approximations in previous modeling approaches. In vivo experiments in the normal human brain yielded results that were consistent with published data.
authors: Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, 04103 Leipzig, Germany. dirk.mueller@cbs.mpg.de
authors: Dirk K
authors: DK
authors: Müller
authors: André
authors: A
authors: Pampel
authors: Harald E
authors: HE
authors: Möller
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D046911:Macromolecular Substances / Q000032:analysis* / Q000737:chemistry*; D060526:Magnetic Fields; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008956:Models, Chemical; D057054:Molecular Imaging / Q000379:methods*; D011522:Protons
chemical_list: D046911:Macromolecular Substances; D011522:Protons