Abstract: Based on Zimmerman-Brittins model of spin exchange between two phases,the line-shape relaxation correlation technique, also called spin-grouping technique,was analysed.The programs processing experimental data are complied.This technique can be used in the study of NMR apparent and inherent relaxation characteristic of different components in heterogeneous system.In this paper the sample is the healthy fresh mouse muscle.T₁ experment(π-τ-π/2) was performed using h-h,s-h,s-s pulse sequence at high field(0.9T).The results indicate that the T₁=1050 ms,T₂=4500μs component is caused by "free water" in muscle, the proton relative content of which is 69%;the T₁=530 ms,T₂=26 μs component is caused by "bound water"in muscle,the proton relative content of which is 9%, the T₁=530 ms,T₂=1250μs component is caused by various large molecules and organic compounds in muscle,the proton relative content is 9%;the T₁=470 ms,T₂=1250 μs componentis eaused by the fat in the sample,the proton relative content is 13%. Between theproton in muscle tissues and the proton in water fast exchange is dominant but thereis no exchange between the proton in fat and other components.

Key words: NMR, Apparent relaxation, Inherent relaxation, Spin exchange