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.
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.
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 |
Read more about this topic: Relaxation (NMR)
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