Table 2:
T2 weighting of the spin echoes at 1.5T and 3T
| T2 Weighting for Creatine | FID | Echo 1 | Echo 2 | Echo 3 | Echo 4 | Echo 5 | Echo 6 | Sum |
|---|---|---|---|---|---|---|---|---|
| 1.5T (TE = 288 ms) | 100 | 26.8 | 7.2 | 1.9 | 0.5 | 0.14 | 0.04 | 36.4 |
| 3T (TE = 144 ms) | 100 | 39.7 | 15.8 | 6.3 | 2.5 | 1.0 | 0.4 | 65.7 |
Note:—FID indicates free induction decay; TE, echo time. Values are expressed as percentages. T2 weighting factors calculated for creatine for different spin echoes relative to the FID signal strength using an echo time and echo spacing of 288 ms at 1.5T and an echo time and echo spacing of 144 ms at 3T. The T2 value of creatine in white matter was assumed to be 219 ms at 1.5T11 and 156 ms at 3T.12 The total fraction of the FID signal intensity, collected over 4 echoes at 1.5T and over 6 echoes at 3T, is stated in the last column.