Terada H, Barkovich A J, Edwards M S, Ciricillo S M
Department of Radiology, University of California, San Francisco, USA.
AJNR Am J Neuroradiol. 1996 Apr;17(4):755-60.
To characterize the temporal evolution of the foci of T1 shortening in basal ganglia lesions in patients with neurofibromatosis type 1 (NF-1).
A retrospective review of MR images of 37 patients with NF-1 revealed 8 patients in whom regions of T1 shortening were noted in the basal ganglia. We reviewed sequential images obtained in these selected patients with special attention to chronological changes in the foci of T1 shortening and their relationship to changes on T2-weighted images.
Regions of short T1 in the globus pallidus were observed in 8 patients. In 2 of 3 patients in whom foci of T1 shortening were not identified on the initial imaging study, T1 shortening developed and T2 prolongation diminished after an initial increase. In the third patient, T1 and T2 prolongation appeared simultaneously. Sequential scans in the other 5 patients, in whom areas of increased signal intensity in the globus pallidus were present on both T1-weighted and T2-weighted images on the initial MR examination, showed a diminution in the size of the region of T2 prolongation in 2 patients, an increase in the size of the region of T2 prolongation in 1 patient, a mixed pattern of change in the size of the region of T2 prolongation in 1 patient, and no change in the region of T2 prolongation in 1 patient. During the periods of these T2 changes, the areas of T1 shortening showed no significant interval change.
The foci of prolonged T2 relaxation in the basal ganglia appear to evolve in a manner similar to the foci of T2 prolongation in the white matter of the posterior fossa. However, the corresponding foci of short T1 in the basal ganglia may evolve with a different time course. In some patients, the foci of short T1 develop at a later time than the T2 prolongation and progress; these foci of short T1 do not appear to regress over periods as long as 90 months. Possible causes of the T1 shortening are remyelination and calcification.
描述1型神经纤维瘤病（NF-1）患者基底节病变中T1缩短灶的时间演变特征。
对37例NF-1患者的磁共振图像进行回顾性分析，发现8例患者基底节区存在T1缩短区域。我们回顾了这些选定患者的序列图像，特别关注T1缩短灶的时间变化及其与T2加权图像变化的关系。
8例患者苍白球出现T1缩短区域。在初始影像学检查未发现T1缩短灶的3例患者中，有2例在初始增加后出现T1缩短且T2延长减轻。在第3例患者中，T1和T2延长同时出现。另外5例患者在初始磁共振检查的T1加权和T2加权图像上苍白球均有信号强度增加区域，序列扫描显示2例患者T2延长区域大小减小，1例患者T2延长区域大小增加，1例患者T2延长区域大小呈混合变化模式，1例患者T2延长区域无变化。在这些T2变化期间，T1缩短区域无明显间隔变化。
基底节区T2弛豫延长灶的演变方式似乎与后颅窝白质T2延长灶相似。然而，基底节区相应的T1缩短灶可能以不同的时间进程演变。在一些患者中，T1缩短灶比T2延长出现得晚且持续进展；这些T1缩短灶在长达90个月的时间内似乎不会消退。T1缩短的可能原因是再髓鞘化和钙化。
