Wu Mei, Ma Ya-Jun, Kasibhatla Akhil, Chen Mingxin, Jang Hyungseok, Jerban Saeed, Chang Eric Y, Du Jiang
Department of Radiology, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou, Guangdong, China.
Department of Radiology, University of California San Diego, San Diego, California, USA.
Magn Reson Med. 2020 Nov;84(5):2551-2560. doi: 10.1002/mrm.28317. Epub 2020 May 17.
To investigate the magic angle effect in three-dimensional ultrashort echo time Cones Adiabatic T (3D UTE Cones-AdiabT ) imaging of articular cartilage at 3T.
The magic angle effect was investigated by repeated 3D UTE Cones-AdiabT imaging of eight human patellar samples at five angular orientations ranging from 0° to 90° relative to the B field. Cones continuous wave T (Cones-CW-T ) and Cones- sequences were also applied for comparison. Cones-AdiabT , Cones-CW-T and Cones- values were measured for four regions of interest (ROIs) (10% superficial layer, 60% transitional layer, 30% radial layer, and a global ROI) for each sample at each orientation to evaluate their angular dependence.
3D UTE Cones-AdiabT values increased from the radial layer to the superficial layer for all angular orientations. The superficial layer showed the least angular dependence (around 4.4%), while the radial layer showed the strongest angular dependence (around 34.4%). Cones-AdiabT values showed much reduced magic angle effect compared to Cones-CW-T and Cones- values for all four ROIs. On average over eight patellae, Cones-AdiabT values increased by 27.2% (4.4% for superficial, 23.8% for transitional, and 34.4% for radial layers), Cones-CW-T values increased by 76.9% (11.3% for superficial, 59.1% for transitional, and 117.8% for radial layers), and Cones- values increased by 237.5% (87.9% for superficial, 262.9% for transitional, and 327.3% for radial layers) near the magic angle.
The 3D UTE Cones-AdiabT sequence is less sensitive to the magic angle effect in the evaluation of articular cartilage compared to Cones- and Cones-CW-T .
研究3T场强下三维超短回波时间圆锥绝热T（3D UTE Cones-AdiabT）关节软骨成像中的魔角效应。
通过对8个人类髌骨样本在相对于B场从0°到90°的五个角度方向上进行重复的3D UTE Cones-AdiabT成像来研究魔角效应。还应用了圆锥连续波T（Cones-CW-T）和圆锥序列进行比较。在每个方向上，对每个样本的四个感兴趣区域（ROI）（10%表层、60%过渡层、30%放射状层和一个整体ROI）测量Cones-AdiabT、Cones-CW-T和圆锥值，以评估它们的角度依赖性。
在所有角度方向上，3D UTE Cones-AdiabT值从放射状层到表层增加。表层显示出最小的角度依赖性（约4.4%），而放射状层显示出最强的角度依赖性（约34.4%）。对于所有四个ROI，Cones-AdiabT值与Cones-CW-T和圆锥值相比，魔角效应显著降低。在八个髌骨上平均而言，Cones-AdiabT值增加了27.2%（表层为4.4%，过渡层为23.8%，放射状层为34.4%），Cones-CW-T值增加了76.9%（表层为11.3%，过渡层为59.1%，放射状层为117. Eight%），在魔角附近，圆锥值增加了237.5%（表层为87.9%，过渡层为262.9%，放射状层为327.3%）。
与圆锥和Cones-CW-T相比，3D UTE Cones-AdiabT序列在评估关节软骨时对魔角效应不太敏感。
