Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.
J Magn Reson Imaging. 2019 Oct;50(4):1207-1218. doi: 10.1002/jmri.26664. Epub 2019 Jan 28.
In addition to the articular cartilage, osteoarthritis (OA) affects several other tissues such as tendons, ligaments, and subchondral bone. T1 relaxation study of these short T tissues may provide a more comprehensive evaluation of OA.
To develop a 3D spin-lattice relaxation in the rotating frame (T ) prepared zero echo time (ZTE)-based pointwise encoding time reduction with radial acquisition (3D-T -PETRA) sequence for relaxation mapping of semisolid short-T tissues on a clinical 3 T scanner.
Prospective.
Phantom, two bovine whole knee joint and Achilles tendon specimens, 10 healthy volunteers with no known inflammation, trauma or pain in the knee or ankle.
FIELD STRENGTH/SEQUENCE: A customized PETRA sequence to acquire fat-suppressed 3D T -weighted images tissues with semisolid short T / relaxation times in the knee and ankle joints at 3 T.
Mono- and biexponential T relaxation components were assessed in the patellar tendon (PT), anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), and Achilles tendon (AT).
Kruskal-Wallis with post-hoc Dunn's test for multiple pairwise comparisons.
Phantom and ex vivo studies showed the feasibility of T relaxation mapping using the proposed 3D-T -PETRA sequence. The in vivo study demonstrated an averaged mono-T relaxation of (median [IQR]) 15.9 [14.5] msec, 23.6 [9.4] msec, 17.4 [7.4] msec, and 5.8 [10.2] msec in the PT, ACL, PCL, and AT, respectively. The bicomponent analysis showed the short and long components (with their relative fractions) of 0.65 [1.0] msec (46.9 [15.3]%) and 37.3 [18.4] msec (53.1 [15.3]%) for PT, 1.7 [2.1] msec (42.5 [12.5]%) and 43.7 [17.8] msec (57.5 [12.5]%) for ACL, and 1.2 [1.9] msec (42.6 [14.0]%) and 27.7 [14.7] msec (57.3 [14.0]%) for PCL and 0.4 [0.02] msec (58.8 [13.3]%/) and 31.3 [10.8] msec (41.2 [13.3]%) for AT. Statistically significant (P ≤ 0.05) differences were observed in the mono- and biexponential relaxation between several regions.
The 3D-T -PETRA sequence allows volumetric, isotropic (0.78 × 0.78 × 0.78 mm), biexponential T assessment with corresponding fractions of the tissues with semisolid short T / .
2 Technical Efficacy Stage: 1 J. Magn. Reson. Imaging 2019;50:1207-1218.
除了关节软骨，骨关节炎（OA）还会影响到其他一些组织，如肌腱、韧带和软骨下骨。这些短 T 组织的 T1 弛豫研究可能为 OA 提供更全面的评估。
在临床 3T 扫描仪上开发一种基于三维旋转晶格弛豫在旋转框架（T1）的准备零回波时间（ZTE）的点编码时间减少的径向采集（3D-T1-PETRA）序列，用于半固态短 T 组织的弛豫图。
前瞻性。
幻影、两个牛整个膝关节和跟腱标本、10 名无膝关节或踝关节炎症、创伤或疼痛的健康志愿者。
场强/序列：一种定制的 PETRA 序列，用于在 3T 时采集具有半固态短 T1/弛豫时间的膝关节和踝关节的脂肪抑制 3D T1 加权图像组织。
在髌腱（PT）、前交叉韧带（ACL）、后交叉韧带（PCL）和跟腱（AT）中评估单指数和双指数 T1 弛豫分量。
Kruskal-Wallis 检验，用于多个配对比较的事后 Dunn 检验。
幻影和离体研究表明，使用所提出的 3D-T1-PETRA 序列进行 T1 弛豫映射是可行的。在体内研究中，在 PT、ACL、PCL 和 AT 中分别平均观察到单 T1 弛豫时间为（中位数[IQR]）15.9[14.5]msec、23.6[9.4]msec、17.4[7.4]msec 和 5.8[10.2]msec。双指数分析显示，0.65[1.0]msec（46.9[15.3]%）和 37.3[18.4]msec（53.1[15.3]%）的短和长分量（相对分数）和 1.7[2.1]msec（42.5[12.5]%）和 43.7[17.8]msec（57.5[12.5]%）在 ACL 中，和 1.2[1.9]msec（42.6[14.0]%）和 27.7[14.7]msec（57.3[14.0]%）在 PCL 和 0.4[0.02]msec（58.8[13.3]%/）和 31.3[10.8]msec（41.2[13.3]%）在 AT 中。在几个区域的单指数和双指数弛豫之间观察到统计学显著（P≤0.05）差异。
3D-T1-PETRA 序列允许具有半固态短 T1/弛豫时间的组织的体积、各向同性（0.78×0.78×0.78mm）、双指数 T1 评估以及相应的分数。
2 技术功效阶段：1 J. Magn. Reson. Imaging 2019;50:1207-1218.
