Jones C, MacKay A, Rutt B
Tom Lawson Family Imaging Research Labs, John P. Robarts Research Institute, London, Ontario, Canada.
Magn Reson Imaging. 1998;16(1):83-5. doi: 10.1016/s0730-725x(97)00250-6.
MRI phantoms are an important part of any experiment because they provide a reference of known parameters. There are many choices of mono-exponential T2 phantoms, but few choices for bi-exponential T2 phantoms. We have found that dairy cream provides an excellent bi-exponential T2 model with similar relaxation times to those found in white matter. Five cream phantoms of different milk fat percentages (2, 6, 10, 18 and 35 %) were imaged with an optimized Carr-Purcell-Meiboom-Gill sequence. The decay curves for each of the phantoms were fit using Non-Negative Least Squares. We found that the short T2 component fraction relative to the total energy in the distribution correlated linearly (r = 0.9973) with the milk fat percentage. The short T2 time was 38+/-4 ms and the long T2 time was 135+/-4 ms.
磁共振成像（MRI）体模是任何实验的重要组成部分，因为它们提供了已知参数的参考。单指数T2体模有很多选择，但双指数T2体模的选择很少。我们发现，乳脂提供了一个出色的双指数T2模型，其弛豫时间与白质中的弛豫时间相似。使用优化的 Carr-Purcell-Meiboom-Gill 序列对五个不同乳脂百分比（2%、6%、10%、18% 和 35%）的乳脂体模进行成像。使用非负最小二乘法拟合每个体模的衰减曲线。我们发现，相对于分布中的总能量，短T2成分分数与乳脂百分比呈线性相关（r = 0.9973）。短T2时间为38±4毫秒，长T2时间为135±4毫秒。
