Magnetic resonance of water protons in fresh human blood plasma.

Spin-lattice (T1-) relaxation times of fresh human blood plasma at 13.2 MHz and 29 degrees C ranged from 1263 milliseconds (msec) to 1709 msec. Spin-spin (T2-) relaxation times of those samples were between 446 msec and 753 msec. Proton magnetic resonance (p.m.r.) phantoms of such blood plasma were made with ferric chloride and corn starch in dilute hydrochloric acid, and also in dilute sulfuric acid. Their Fe3+ ion concentrations approximated 138 micrograms (micrograms) per deciliter (dl). Both T1 and T2 of any of these p.m.r. phantoms were within limits of those described above for fresh human blood plasma. Lowering of the concentration of the Fe3+ ion--in an experimental corn starch solution--was manifested in longer T1.