Nieminen M T, Rieppo J, Töyräs J, Hakumäki J M, Silvennoinen J, Hyttinen M M, Helminen H J, Jurvelin J S
Department of Anatomy, University of Kuopio, Kuopio, Finland.
Magn Reson Med. 2001 Sep;46(3):487-93. doi: 10.1002/mrm.1218.
It has been suggested that orientational changes in the collagen network of articular cartilage account for the depthwise T2 anisotropy of MRI through the magic angle effect. To investigate the relationship between laminar T2 appearance and collagen organization (anisotropy), bovine osteochondral plugs (N = 9) were T2 mapped at 9.4T with cartilage surface normal to the static magnetic field. Collagen fibril arrangement of the same samples was studied with polarized light microscopy, a quantitative technique for probing collagen organization by analyzing its ability to rotate plane polarized light, i.e., birefringence (BF). Depthwise variation of safranin O-stained proteoglycans was monitored with digital densitometry. The spatially varying cartilage T2 followed the architectural arrangement of the collagen fibril network: a linear positive correlation between T2 and the reciprocal of BF was established in each sample, with r = 0.91 +/- 0.02 (mean +/- SEM, N = 9). The current results reveal the close connection between the laminar T2 structure and the collagen architecture in histologic zones.
有人提出，关节软骨胶原网络的取向变化通过魔角效应解释了MRI的深度方向T2各向异性。为了研究层状T2表现与胶原组织（各向异性）之间的关系，对牛骨软骨栓（N = 9）在9.4T下进行T2成像，软骨表面垂直于静磁场。用偏光显微镜研究相同样本的胶原纤维排列，这是一种通过分析其旋转平面偏振光的能力（即双折射，BF）来探测胶原组织的定量技术。用数字密度测定法监测番红O染色的蛋白聚糖的深度变化。空间变化的软骨T2遵循胶原纤维网络的结构排列：在每个样本中，T2与BF的倒数之间建立了线性正相关，r = 0.91 +/- 0.02（平均值 +/- 标准误，N = 9）。目前结果揭示了组织学区域中层状T2结构与胶原结构之间的紧密联系。
