The spin-lattice relaxation time in the blood of healthy subjects and patients with malignant blood disease.

To establish which constituents of blood influence the NMR relaxation time T1 of water protons in malignant blood diseases, 55 blood samples were studied (20 from healthy donors and 35 from patients with leukaemia, myelofibrosis and multiple myeloma). Relaxation time measurements were performed at 19.8 MHz resonance frequency and at a temperature of 33 +/- 1 degree C. There is a significant elevation of T1 over the normal level in whole blood, packed cells, and plasma of patients with blood disease. The relaxation rate R1 (= 1/T1) depends very strongly on the ratio of dry solids to water, which is in accordance with the three-state fast-exchange relaxation model.