UTE bi-component analysis of T2* relaxation in articular cartilage.
UTE bi-component analysis of T2* relaxation in articular cartilage.
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关节软骨 T2 松弛的 UTE 双成分分析
DOI：
10.1016/j.joca.2015.08.017
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发表时间：
2016-02
影响因子：
7
通讯作者：
Du J
中科院分区：
文献类型：
--
作者：
Shao H;Chang EY;Pauli C;Zanganeh S;Bae W;Chung CB;Tang G;Du J
使用超短回波时间（UTE）成像和双成分分析确定关节软骨中的T2* 弛豫，重点是深层桡骨和钙化软骨。使用二维（2D）UTE和Car-Purcell-Meiboom-Gill（CPMG）序列对10个髌骨样本进行成像。用双组分模型拟合UTE图像以计算T2* 和相对分数。用单组分模型拟合CPMG图像以计算T2。软骨下骨上方的高信号线为桡骨深部钙化软骨。用组织病理学和偏振光显微镜（PLM）分析T2*、分数和T2的深度和方向依赖性，确认关节软骨的正常区域。提出了一种用于体内应用的交错多回波UTE采集方案（n = 5）。短T2* 值在整个软骨深度上保持相对恒定，而长T2* 值和长T2* 分数倾向于从软骨下骨到浅表软骨增加。长T2*s和T2 s对从内侧到外侧关节面的所有软骨层都显示出显著的魔角效应，而短T2* 值和T2* 分数对魔角效应不敏感。桡骨深段和钙化软骨在体外的平均短T2* 为0.80 ± 0.05 ms，短T2* 分数为39.93 ± 3.05%;在体内的平均短T2* 为0.93 ± 0.58 ms，短T2* 分数为35.03 ± 4.09%。UTE双组分分析可以表征跨软骨深度的短和长T2* 值和分数，包括深桡侧和钙化软骨。短T2* 值和T2* 分数是魔角不敏感的。
To determine T2* relaxation in articular cartilage using ultrashort echo time (UTE) imaging and bi-component analysis, with an emphasis on the deep radial and calcified cartilage. Ten patellar samples were imaged using two-dimensional (2D) UTE and Car-Purcell-Meiboom-Gill (CPMG) sequences. UTE images were fitted with a bi-component model to calculate T2* and relative fractions. CPMG images were fitted with a single-component model to calculate T2. The high signal line above the subchondral bone was regarded as the deep radial and calcified cartilage. Depth and orientation dependence of T2*, fraction and T2 were analyzed with histopathology and polarized light microscopy (PLM), confirming normal regions of articular cartilage. An interleaved multi-echo UTE acquisition scheme was proposed for in vivo applications (n = 5). The short T2* values remained relatively constant across the cartilage depth while the long T2* values and long T2* fractions tended to increase from subchondral bone to the superficial cartilage. Long T2*s and T2s showed significant magic angle effect for all layers of cartilage from the medial to lateral facets, while the short T2* values and T2* fractions are insensitive to the magic angle effect. The deep radial and calcified cartilage showed a mean short T2* of 0.80 ± 0.05 ms and short T2* fraction of 39.93 ± 3.05% in vitro, and a mean short T2* of 0.93 ± 0.58 ms and short T2* fraction of 35.03 ± 4.09% in vivo. UTE bi-component analysis can characterize the short and long T2* values and fractions across the cartilage depth, including the deep radial and calcified cartilage. The short T2* values and T2* fractions are magic angle insensitive.