Journal of Bioengineering & Biomedical Science

Lars Malmgren

Publications

• Research Article
  Paramagnetic Ions Affect Relaxation Rate Dispersion of Blood: Implications for Magnetic Resonance Relaxation Dispersion Imaging
  Author(s): Bertil R.R. Persson, Lars Malmgren and Leif G. SalfordBertil R.R. Persson, Lars Malmgren and Leif G. Salford
  
  The proton relaxation rate dispersion of paramagnetic ions in blood samples was studied in the frequency interval from 10 kHz to 10 MHz. With the Field cycling method we applied, the samples were first magnetized by a relatively high magnetic field (0.5 T). By electronic means this field was rapidly (1 ms) reduced to a lower value in the interval 0.1 mT - 0.5 T, where the excited proton spin may relax during a time interval of about 3·T1max. Then the magnetic field is again quickly raised up to the higher level for the detection of the NMR-signal. The relaxation characteristics were analyzed by applying a model with three compartments of water proton-spin exchange. For each compartment we estimated a correlation frequency by fitting the dispersion curves to a sum of Lorentz distributions. We found that low concentrations of paramagnetic ions have a large influence on the relaxati.. Read More»
  DOI: 10.4172/2155-9538.1000105

  Abstract PDF