[Effects of blood oxygenation on the shape of a NMR signal]

The relationship of the width of a NMR proton signal from blood to its oxygenation degree was examined. Its width is shown to consist of a symmetrical spread caused by a dipole-dipole interaction, and increasing (with reduced oxygenation) asymmetrical spreading induced by the fact that erythrocytes are distorted from the spherical shape. The shape of red blood cells can be controlled by the ratio of asymmetrical spreading to the shift of signal resonance frequency.