Relaxation (NMR) - Common Relaxation Time Constants in Human Tissues

Common Relaxation Time Constants in Human Tissues

Following is a table of the approximate values of the two relaxation time constants for nonpathological human tissues, just for simple reference.


At a main field of 1.5 T
Tissue Type Approximate T1 value in ms Approximate T2 value in ms
Adipose tissues 240-250 60-80
Whole blood (deoxygenated) 1350 50
Whole blood (oxygenated) 1350 200
Cerebrospinal fluid (similar to pure water) 4200 - 4500 2100-2300
Gray matter of cerebrum 920 100
White matter of cerebrum 780 90
Liver 490 40
Kidneys 650 60-75
Muscles 860-900 50

Following is a table of the approximate values of the two relaxation time constants for chemicals that commonly show up in human brain magnetic resonance spectroscopy (MRS) studies, physiologically or pathologically.


At a main field of 1.5 T
Signals of Chemical Groups Relative resonance frequency Approximate T1 value (ms) Approximate T2 value (ms)
Creatine (Cr) and Phosphocreatine (PCr) 3.0 ppm gray matter: 1150-1340,
white matter: 1050-1360		 gray matter: 198-207,
white matter: 194-218
N-Acetyl group (NA),
mainly from N-Acetylaspartate (NAA)		 2.0 ppm gray matter: 1170-1370,
white matter: 1220-1410		 gray matter: 388-426,
white matter: 436-519
—CH3 group of
Lactate		 1.33 ppm
(doublet: 1.27 & 1.39 ppm)		 (To be listed) 1040

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