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Relaxation enhancement of the transverse magnetization of water protons in paramagnetic suspensions of red blood cells.
- Source :
-
Magnetic resonance in medicine [Magn Reson Med] 1995 Nov; Vol. 34 (5), pp. 713-20. - Publication Year :
- 1995
-
Abstract
- The enhancement of the water proton transverse relaxation, delta R2, brought about by a difference between intra and extracellular paramagnetic susceptibilities in a suspension of red blood cells (RBC) has been evaluated both experimentally and theoretically in terms of (i) the refocusing interval, delta 180, of a CPMG pulse sequence, (ii) the difference in paramagnetic susceptibility, and (iii) the shape of the cell surface. At a hematocrit of 45, the increase in the relaxation enhancement, delta R2, with increasing delta 180, was a factor of two greater for the naturally biconcave RBC, than for the quasi-spherical RBC in hypotonic suspensions. This difference could be modeled in terms of a transmembrane correlation time, tau = 5.5 ms, across an RBC surface characterized by a demagnetizing factor which differs by 0.13 from that of a sphere. The increase in delta R2 with increasing magnetization difference between the RBC and its surroundings was found to be marginally less than quadratic, both experimentally and from the model.
- Subjects :
- Animals
Computer Simulation
Dogs
Hematocrit
Erythrocytes
Magnetics
Water
Subjects
Details
- Language :
- English
- ISSN :
- 0740-3194
- Volume :
- 34
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Magnetic resonance in medicine
- Publication Type :
- Academic Journal
- Accession number :
- 8544692
- Full Text :
- https://doi.org/10.1002/mrm.1910340510