Armspach J P, Gounot D, Rumbach L, Chambron J
Institut de Physique biologique Faculté de Médecine 4, Strasbourg, France.
Magn Reson Imaging. 1991;9(1):107-13. doi: 10.1016/0730-725x(91)90104-t.
In vivo measurement of T2 relaxation times in multiple sclerosis (MS) lesions by magnetic resonance imaging (MRI) is potentially useful for the evaluation of the disease activity. Seven patients with definite MS were investigated over a period of three years (19 examinations), using a whole-body MRI scanner operating at 0.15 T with a specially designed high-power radio-frequency head coil. A modified CPMG sequence with a 180 degree pulse interval of TE = 6 msec and 128 echoes was used for the T2 relaxation measurement of the areas of increased signal (AIS) and white matter (WM). A biexponential T2 analysis of each pixel of the spin-echo images was computed. The T2 relaxation processes were found to be a monoexponential function in WM. The T2 relaxation times of apparently normal white matter in MS patients was significantly longer than in control subjects. The T2 relaxation curves of the AIS were found in most cases to fit a biexponential function characterized by a short and a long T2. T2 long relaxation times of AIS were spread out over a wide range (150-560 msec). The study of T2 long histograms shows that some AIS can be divided into two or three parts depending on the T2 long values. Each of these parts may correspond to a pathological process such as edema, demyelination and gliosis. Evolution of T2 relaxation times over a period of time cannot as yet be correlated with modifications in the clinical state.
通过磁共振成像（MRI）对多发性硬化症（MS）病灶进行T2弛豫时间的体内测量，对于评估疾病活动具有潜在的应用价值。在三年时间里（共19次检查），对7例确诊为MS的患者进行了研究，使用的是一台全身MRI扫描仪，其场强为0.15 T，并配备了专门设计的高功率射频头部线圈。采用改良的CPMG序列，TE = 6毫秒，180度脉冲间隔，128个回波，用于测量信号增强区域（AIS）和白质（WM）的T2弛豫。对自旋回波图像的每个像素进行双指数T2分析。结果发现，白质中的T2弛豫过程为单指数函数。MS患者中看似正常白质的T2弛豫时间显著长于对照组。在大多数情况下，AIS的T2弛豫曲线符合双指数函数，其特征为短T2和长T2。AIS的T2长弛豫时间分布在较宽的范围内（150 - 560毫秒）。T2长直方图研究表明，根据T2长值，一些AIS可分为两部分或三部分。这些部分中的每一个可能对应于诸如水肿、脱髓鞘和胶质增生等病理过程。一段时间内T2弛豫时间的变化目前尚无法与临床状态的改变相关联。
