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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